High Definition Videoconferencing: Codec Performance, Security, and Collaboration Tools ‡

Gregg Trueb (Student), Suzanne Lammers (Student), Prasad Calyam (PI) Ohio Supercomputer Center, USA; Email: {gtrueb, slammers, pcalyam}@osc.edu

Abstract Internet Videoconferencing has rapidly emerged as a beneficial technology to many application domains. Recent developments in videoconferencing technology are allowing users to videoconference using high definition video (HDVC). The HDVC technology has many advantages over the current standard definition videoconferencing (SDVC) and is being seen as vital technology in health care, education, judicial, and business. The goal of this report is to determine the differences between HDVC and SDVC in terms of end-user usability and reliability. Specifically, we compare their traffic characteristics, subjective and objective Quality of Experience (QoE) measurements and study the ways to secure them on the Internet. This report will also inform potential users about the requirements, strengths and weaknesses of HDVC and will assess its future as a means of communication. We conclude this paper with a comparison of different collaboration tools and their future in HDVC.

‡ This work has been sponsored by the American Distance Consortium and the National Science Foundation under the Summer Research Experience for Undergraduates (REU) program. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Table of Contents

1. Introduction 1 2. Background and Related Work 2

2.1. Internet Videoconferencing 2 2.2. HDVC compared with SDVC 3 2.3. Video Codecs 4 2.4. Security Concerns 4 2.5. Collaboration Tools 5

3. Methodology and Results 8 3.1. Codec Performance 8

3.1.1 Test bed setup 8 3.1.2. Traffic Characteristics 10 3.1.3. End-user Quality of Experience 16 3.1.4: Performance conclusions 19

3.2. Security 20 3.2.1. GNU Gatekeeper 21 3.2.2. Polycom V2IU solution 22 3.2.2. Cisco PIX firewall with “H.323 fixup” 23

3.3. Collaboration 24 3.4. HDVC Applications 25

3.4.1. Health Care 25 3.4.2. Education 25 3.4.3. Judicial 26 3.4.4. Business 26

4. The Future for HDVC 26 5. Conclusions 28 6. Acknowledgements 28 7. Bibliography 29 Appendix I: Annual Distance Teaching and Learning Conference – Trip Report I Appendix II: Features comparison of Collaboration tools III Appendix III: Research Poster XV

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1. Introduction It is hard to argue that the most defining change in the last few decades has been in the area of communication. Businesses, educators and consumers alike are able to transfer ideas, pictures and documents instantly using the Internet. This report deals with videoconferencing, specifically high definition videoconferencing (HDVC). The goal is to examine the feature sets, traffic characteristics, security issues, and future uses in order to assess the usability and reliability of HDVC technology.

Performance problems associated with videoconferencing include latency, jitter, and packet loss. Latency, otherwise known as delay, is the time it takes for a packet of information to travel from a source to a receiving system [1]. If a videoconferencing system begins to have long latencies, the video conference is no longer real time which hinders its effectiveness. It effects interaction because the participants may interrupt each other unknowingly. Jitter is when network conditions cause the latency to be inconsistent throughout a videoconferencing session [1]. Jitter can make a simple conversation difficult because of the unpredictable performance that makes it difficult to adjust buffer sizes at the receiving ends. Packet loss is when pieces of information are lost over the network [1] [13]. In videoconferencing, packet loss causes the video to tile or sound snippets to dropout. These issues might be due to the amount of traffic in the network or improperly configured or inadequate network equipment.

Also affecting videoconferencing performance are security measures taken by network administrators. There are two conflicting forces in networking: security and usability. With both areas being essential, engineers and software designers are forced to work in the middle ground when designing systems. This report compares the ways common security measures are dealt with by VC administrators.

The traffic characteristics and end-user Quality of Experience (QoE) in terms of Mean Opinion Scores (MOS) are used to compare HDVC and SDVC. Our research is also focused on the collaboration tools in context of HDVC applications. Examining the different features, this report discusses the future of collaboration tools and their integration into HDVC.

The remainder of this report is organized as follows: Section 2 explains related research and literary reviews about high definition video, codecs, collaboration tools, and security concerns of HDVC and SDVC. Section 3 presents the methodology, testbed setup and results of our experiments. The results show the differences in performance between HDVC and SDVC. Section 3 also describes how HDVC is being preferred over SDVC today in different application domains. Finally, in Section 4, our vision on the future of HDVC is described. Section 5 concludes the report.

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2. Background and Related Work 2.1. Internet Videoconferencing

Since its humble beginnings with AT&T in 1930[1], videoconferencing (VC) has become a common form of communication. Unlike telephone or text chat, videoconferencing allows for a more realistic conversation between two physically separated parties over the Internet. It facilitates easier communication between barriers such as clean rooms and nuclear installations, or distances with multinational corporations, military, or distance learning. Aiding the development and growth of VC is continual improvements in network technology and infrastructure. Over 68% of the US population now has direct access to the Internet, which continues to increase every year [24]. Even more instrumental to VC growth is corporations, research, and educational facilities gaining access to increasingly capable networks. Corporations, researchers, and even families are now able to hold meetings and communicate over the Internet, thus saving time and travel costs. Educators are also taking advantage by using the technology to reach a larger base of students in distance learning applications sometimes including multinational classrooms. The improved broadband access is allowing more and more people to use VC technology. Like in any other form of communication technology there are standards in place to foster compatibility in VC. The most common standard for videoconferencing is the H.323 standard. In 1996, the International Telecommunications Union (ITU-T) completed the first version of the H.323 based on earlier versions of H.32x standards. H.323 provides a means for communication between a variety of different hosts such as end points, gatekeepers and gateways. The protocol was designed to communicate through packet based networks such as, IP, local area networks (LAN) and wide area networks (WAN) [1]. This makes it perfect for the modern Internet which is based on the IP protocol. Rivaling the H.323 standard is a standard developed by the Internet Engineering Task Force (IETF) around the same time. This technology is called Session Initiation Protocol (SIP) which acts as an initiator of communication between endpoints. Unlike H.323, the SIP protocol is independent of the type of data that it is carrying and acts only as a session starter [1]. Many commercial VC systems are compatible with both protocols [18] [15]. Advances in audio and video display, compression/decompression, and transmission technology are being utilized in VC. High definition is a technology that after finding a home in movies and television has started to be incorporated into videoconferencing. High definition videoconferencing (HDVC) provides both a richer and in some situations, a more informative video session. The combination of high definition video and sound provides the participants with a more realistic setting. It has the benefit of decreasing meeting fatigue and loss of attention as well as increasing the use of visually detailed material [25]. Combining these benefits with collaboration tools, effective and efficient meeting can be held across a campus or across the world in inspiring clarity. An example of high definition video frame and standard definition video frame is in Figure 2.1.

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Figure 2.1: Visually apparent difference between HD (left) and SD (right)

2.2. HDVC compared with SDVC

The differences between HDVC and SDVC systems are in a variety of different areas, most notably in image size and data requirements. Video images are made up of pixels, tiny pieces of color information laid out in a grid to form an image. High definition’s increased resolution, shown in Figure 2.1 and Table 2.1, is due to its use of more pixels within an image than standard definition; this makes the images clearer and more representative of the actual image [2] as shown in Figure 2.1. High definition also requires a larger screen to display video than a standard definition system because of its higher resolution [2]. Table 2.1 shows some of the differences between HDVC and SDVC.

Table 2.1: Comparison of HDVC and SDVC systems High Definition Standard Definition Cost $12,000 [20] - $300,000 $100 - $12,000 [20] Vendors LifeSize

Polycom Sony Tandberg

Polycom Sony Tandberg

Systems LifeSize Room [15] HDX Series [18] PCS-HG90 [16] Edge 95/85/75 [17]

View Station VSX 7000 PCS-TL30 Centric 150 MXP

Features Application Sharing Data Sharing Security

Application Sharing Data Sharing Security

Resolution 1280 x 720 16:9 aspect ratio

704 x 480 4:3 aspect ratio

Primary Video Codecs H.264 H.263

H.263 H.264

Dialing Speeds 128 Kb/s, 256 Kb/s, 384 Kb/s 512 Kb/s, 768 Kb/s, 1024 Kb/s 1152 Kb/s, 1472 Kb/s, 1920 Kb/s, 2500 Kb/s, 3000 Kb/s, 4000 Kb/s, 5000 Kb/s

128 Kb/s, 256 Kb/s, 384 Kb/s 512 Kb/s, 768 Kb/s

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2.3. Video Codecs

Videoconferencing relies on video codecs to compress and decompress the information being transmitted, because using the raw data would use more network resources than necessary or in most cases possible. Video codecs use static areas, irrelevant information and predictive algorithms to compress the number of bits needed for a sequence. The compression and decompression of data can allow for a lower bandwidth than would be necessary without it [13]. These video codecs need to be patched regularly otherwise it can lead to functionality problems during a videoconference [12]. The performance of a videoconferencing system is directly related to a video codec’s ability to cope with different network conditions on the Internet.

The two primary video codecs used in video conferencing are H.263 and H.264. Both video codecs use a variety of different schemes such as static segments and inter-frame memory to compress and decompress the video streams to a manageable size. One of the points of comparison is rooted in the codecs’ ability to compress the necessary data. Because of its increased frame size, and resolution HDVC requires an increased amount of data. This means that the systems performance has an increased reliance on the video codecs performance.

H.263 which was developed in the mid 90’s and has undergone a few revisions and was a precursor to the H.264 standard. The H.264 was the first video codec designed to be network friendly with many features that help to makeup for lost or delayed packets in the stream. It also provides an increased compression ratio and thus is the codec of choice in HDVC systems. For more information on video codecs, see [33].

2.4. Security Concerns

A fundamental step that network administrators take in securing networks is to deploy a firewall. A firewall is a system that checks information entering and leaving a network. It checks based on a set of rules and either denies or allows the information to pass to its destination. This is a powerful step in preventing hackers and malicious software from gaining access to a network. This however poses a problem for videoconferencing and H.323 based applications specifically. The problem arises due to the method in which firewalls make decisions, which are based on address, port and message type criteria. This information is stored in the header portion of each packet sent through a packet switching network. H.323, which is designed to run on a packet switching network, has two phases: a connection phase and a transmission phase. The connection phase is on a well known port, i.e. 1720, and is easily allowed through a firewall. [1] However in this connection process subsequent transmission ports are negotiated between the two VC units in the body of the control packets. This poses a problem because a normal firewall will have no knowledge of this transaction, so when the transmitted packets reach the firewall on the new port they will be dropped per the firewall rules. In line with firewalls is another mechanism used in modern networks that cause problems in VC situations. Devices that eliminate the need for multiple public IP addresses by converting messages to correspond to internal private IP address, called network address translation (NAT). The problem posed by NAT and a more detailed description of the firewall problem is given in section 3 of this report.

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There are four main solutions to these problems. One is to open the network during videoconferencing session by disabling the firewall on the RTP port range. However, this is not an option in certain situations where security is a high priority and does not solve NAT problems. Solution provided by the open-source community i.e., openH323 in particular is the GNU gatekeeper software. This software runs on a dedicated server that facilitates connections of videoconferencing end-points. Each end-point that wants to engage in videoconferencing first makes a connection to the gatekeeper. The gatekeeper is then responsible for forwarding all traffic between the two end-points on either side of the firewall, effectively working as a way around a closed firewall and NAT devices [27]. In order for the gatekeeper to bypass the firewall, it must have unrestricted access to both the inside and outside of the network. It is therefore placed in a demilitarized zone (DMZ). The problem with the gatekeeper solution is that the gatekeeper itself is vulnerable to attacks and if compromised, allows unrestricted access to the internal network. So users of this solution need to harden the gatekeeper server as much as possible [27]. The next two are commercial solutions offered by Cisco and Polycom. First the Cisco PIX firewall is a device that in normal operation is a powerful versatile firewall. The special feature of the PIX is that is has an implementation of “H.323 fixup.” The firewall itself has the ability to examine the body of H.323 control packets and make decisions based on the contents [28] [29]. The Polycom solution includes the V2IU system which provides routing and firewall solutions. The V2IU system is specially designed to allow H.323 through without compromising security [26]. This is done by the unit examining and effectively relegating H.323 traffic to the units internal DMZ so as not to be checked by the firewall and tunneling them through using the H.460 protocol. 2.5. Collaboration Tools

In addition to videoconferencing being used for Internet collaboration, a whole host of different tools are also available. They provide more ways for people to work together than just using video and voice. The most widely used of these tools is email, though this report is interested in more real time collaboration tools. There are tools available that will allow users to work jointly on documents, software, give presentations, and conduct online training and classes - increasing productivity and reducing cost of travel and lost time. Collaboration tools can be broken up into three main categories: chat, multi-point conferencing and web conferencing. Chat simply allows users to communicate one on one using text/video/voice. Multi-point conferencing is when users are in a many to many environment. Web conferencing is similar to conferencing adding different functionality such as application and desktop sharing. Depending on the situation one or more of these different types may be appropriate. The main feature in most network collaboration tools is usually instant messaging, the sending of text messages from user to user. This is mainly used in the chat format but can be used in a conference form where all users see all messages i.e. chat rooms. Advancing up the scale adds videoconferencing capabilities i.e., voice and video chat. Internet collaboration also gives the ability to move away from simple chat and conferencing, and adds a richer framework for user participation. Features such as

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application and desktop sharing, annotation and white boarding tools allow multiple users to work on the same project simultaneously over the Internet. Advanced features include recording of collaboration sessions, the ability to poll participants, and even to control instruments remotely. The use of these features together allow for highly effective meetings over the Internet.

Internet collaboration tools are separated from each other by their platform, available features and price among other things. Below in Table 2.2 and Table 2.3 are comparison charts of some of the more popular collaboration tools available.

Table 2.2 Comparison of common high-end collaboration tools

Acrobat Connect

Acrobat Connect Pro

Unyte Meeting I-Linc

MSFT Live

Meeting WebEx Horizon

Wimba

Platform Win/Mac/ Linux

Win/Mac/ Linux

Win/Mac/ Linux

Win/Mac/Linux Win Win/Mac/

Linux Win/Mac/

Linux Part List Yes Yes Yes Yes Yes

White Board Yes Yes Yes Yes Yes Yes

File Transfer Yes Yes

App. Sharing Yes Yes Yes Yes Yes Yes Yes

Duplex Audio Yes Yes Yes Yes Yes Yes Yes

Shared Browser Yes Yes Yes Yes

One way Video Yes Yes Yes Yes No No

Text Chat Yes Yes Yes Yes Yes Yes Yes Polling Yes Yes Yes Yes Yes Yes Record Yes Yes Yes Yes Yes Yes H.323

Multicast Yes Yes Yes Possibly Yes Pay

Structure $39/mon $375-750/mon

$0.09- $0.15/min $46K+ $23000 5 Users

$375/m

Notes Present Not all available

Geared toward Class

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Table 2.3 Comparison of common inexpensive collaboration tools

VSee Skype

Unyte +

Skype Evo Ekiga Group

World Gizmo VNC MSFT

Net Meeting

Platform Win Win/ Mac/ Linux

Win/ Mac/ Linux

Win/ Mac/ Linux

LinuxWin/ Mac/ Linux

Win/ Mac/ Linux

Win/ Mac/ Linux

Win

Part List

White Board Form

Of Yes Yes

File Transfer Yes Yes Yes

App. Sharing Yes Yes Yes Yes Yes

Duplex Audio Yes Yes Yes Yes Yes Yes Yes

Shared Browser Yes

Text Chat Yes Yes Yes Yes Yes Yes Yes Yes

Polling

Record Yes Flash Yes Yes Yes

H.323 Yes Yes SIP Yes

Multicast Yes

Pay Structure

Free (Limit) Free $30-

450/year Free Free $25/mon $750 Free Free

Notes Run

through Skype

Server based

Desktop Sharing

only

Out of date

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3. Methodology and Results 3.1. Codec Performance

We gained the information presented in this report by using Internet, electronic journals, interviews with experts and everyday users of HDVC systems and experimental sources. System information was obtained from the VC distributor’s websites and online reviews. OhioLink was used for the electronic journals. Contacts for interviews and assessments for this project were made through the Megaconference mailing list, H.323 forum mailing list, The Ohio State University and OSC. Experimental data was collected through tests run at OSC as described below. The goals of this research are to assess the quality of HDVC streams in different network conditions and compare them to a SDVC stream measured in the same conditions and to compare the traffic characteristics of both. 3.1.1 Test bed setup Shown in Figure 3.1 is a block diagram of the research setup used to collect the data from both HDVC and SDVC systems. The packets leaving the source machine pass through a switch on V-LAN 1. The switch routes the data through a network emulator and then to the other side of the switch running V-LAN 2, where it is sent to the destination unit. The network emulator is capable of inducing bandwidth caps, packet loss, jitter, and delay. This gives the ability to simulate different network conditions in real time.

Figure 3.1: Test bed setup for HD/SD comparison

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Test procedure for traffic characteristics: 1. Connect DVD player to source SD and HD unit 2. Play low motion clip (Streaming Kelly)* 3. Gather packet information using wireshark packet capture program on network

monitor server 4. Play medium motion clip (Foremen sequence)** 5. Repeat step 3 6. Play high motion clip (Soccer sequence)*** 7. Repeat step 3 8. Repeat from step 1 using different dialing speeds for both SD and HD units

Test procedure for MOS measurements:

1. Connect DVD player to source SD and HD units 2. Play, record and have the group watch all three source clips (low*, medium**,

high***) through an open network. 3. Reset the network emulator to good level indicated in table 3.1 below 4. Play, record and have group watch and score all three source clips 5. Reset the network emulator to acceptable level indicated in table 3.1 below 6. Repeat step 4 7. Rest the network emulator to poor level indicated in table 3.1 below 8. Repeat step 4 9. Repeat sequence from 1 for both HD and SD at selected dialing speeds

*Streaming Kelly is a prerecorded video sequence with typical VC video activity levels i.e., talking head movements **Foreman sequence is a prerecorded video sequence with moderate VC video activity levels and camera movement i.e., rapid movements and a few scene changes ***Soccer sequence is a prerecorded video sequence with high VC video activity levels and camera movement i.e., rapid movements and a rapid scene changes

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3.1.2. Traffic Characteristics Figures 3.2 and 3.3 show the instantaneous throughput of SD and HD respectively, at the popular dialing speed of 768 Kbit/s. The plots show both systems hovering somewhere around the available maximum, i.e., 768Kbit/s, when the clip exhibits high and medium motions. A noticeable difference between the two systems is shown in the low motion clip. It is apparent that the HD system used all of the available bandwidth on the low motion clip while the SD system did not.

Bandwidth usage SD 768(Kbit/s)

0

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500

600

700

800

900

0 200 400 600 800 1000

Packet #

Insta

nta

ne

ou

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hro

ug

hp

ut

(Kb

it/

s)

Low motion

Medium Motion

High Motion

Figure 3.2: Bandwidth usage of high, medium, and low motion clips through SD unit

at a dialing speed of 768Kbit/s

Bandwidth usage HD 768 Kbit/s

0

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500

600

700

800

0 200 400 600 800 1000 1200 1400

Packet #

Insta

nta

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hpu

t(K

bit

/s)

Low motion

Medium Motion

High Motion

Figure 3.3: Bandwidth usage of high, medium, and low motion clips through HD unit

at a dialing speed of 768Kbit/s

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What can be seen in contrasting the two systems is that HD has no separation in how the different motion clips are transmitted that was seen in the SD system. Increasing the speed of the HD system to 2500Kbit/s shown below in Figure 3.4, HD still does not seem to show a noticeable difference in bandwidth usage between the different motion clips.

Bandwidth usage HD 2500Kbit/s

2340

2360

2380

2400

2420

2440

2460

2480

2500

2520

2540

0 500 1000 1500

Packet #

Insta

nta

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hro

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hp

ut

(Kb

it/

s)

Low motion

Medium Motion

High Motion

Figure 3.4: Shows the bandwidth usage with low, medium, high motion clips running

HD at a dialing speed of 2500Kbit/s.

This fact is summarized by Figures 3.5 and 3.6 where the average bandwidth

usage of the three clips, high, medium, and low motion, is plotted against the dialing speed for SD and HD.

What can be seen is that the average for HD stays pretty linear with the bandwidth used by the video being slightly less then the dialing for all clips. This shows that the HD system uses all of its available bandwidth and does not seem to discriminate between high and low motion. In contrast, we see in Figure 3.5 that there is a noticeable difference between the average usage in low, medium and high motion clips on the SD system. It is apparent that - the lower the motion in the clip transmitted, lesser available bandwidth is being utilized. Examining figure 3.6 shows that the HD system does not make this distinction.

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Average instantaneous throughput per dialing speed

0

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700

800

900

0 100 200 300 400 500 600 700 800 900

Dialing speed (Kbit/s)

Aver

age

inst

anta

neou

s th

roug

hput

(K

bit/s

)

Low MotionMedium MotionHigh Motion

Figure 3.5: Average bandwidth usage vs. dialing speed of SD system

Average instantaneous throughput per dialing speed

0

500

1000

1500

2000

2500

3000

0 500 1000 1500 2000 2500 3000

Daling speed (Kbit/s)

Aver

age

inst

anta

neou

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roug

put

(Kbi

t/s)

Low MotionMedium MotionHigh Motion

Figure 3.6: Average bandwidth usage vs. dialing speed of HD system

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Another difference that is worth noting is the manner in which the two systems manage the sizes of their video packets. Figures 3.7 and 3.8 show the two using a different packet size strategy. The medium motion clip run through SD shows a wide variety of packet sizes, ranging from approximately 200 bytes to slightly over 1400bytes with the average size at 1144. There does not seem to be a noticeable pattern to the packet size distribution. In Figure 3.8 the packet sizes of the medium clip played through the HD system at 768 Kbit/s is shown. The HD system uses a similar range as the SD system from approximately 200 bytes to 1400 bytes. The difference is shown in the average, with the HD system having an average packet size of 775 bytes. From Figures 3.2 and 3.3, we can see that the two systems running the medium motion clip use approximately the same bandwidth. Combining this with the difference in packet size distribution would indicate that the SD takes a slower but larger packet size approach than the HD system, with the SD having a larger inter-packet time.

Packet length SD medium motion 768Kbit/s

0

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600

800

1000

1200

1400

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0 200 400 600 800 1000 1200

Packet #

Pa

ck

et

len

gth

(b

its)

Figure 3.7: Shows the packet length variability during a medium motion clip through

SD at a dialing speed of 768Kbit/s

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Packet length HD medium motion 768Kbit/s

0

200

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600

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1000

1200

1400

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0 200 400 600 800 1000 1200 1400

Packet #

Pa

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len

gth

(b

its)

Figure 3.8: Shows the packet length variability during a medium motion clip through

HD at a dialing speed of 768Kbit/s The HD system starts to look like the SD in terms of packet sizes when the dialing

speed is increased, which is shown in Figure 3.9 where the packet sizes are plotted at 2500Kbit/s. At the 2500Kbit/s, the average packet sizes jumps higher than 1280 bytes like the SD clip nearing the packet size constraints for Ethernet. With both systems, the increasing dialing speed leads to an increase in packet size with both leveling off at around 1400 bytes maximum. This trend is shown in Figures 3.10 and 3.11 which graph the average packet sizes to dialing speed using the low motion and medium motion clip. The packet size has an increasing trend for both systems with higher motion clips. Figure 3.10 shows that there is a distinct difference in packet size between the medium and low motion clip, while in Figure 3.11, no noticeable difference is evident.

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Packet length HD medium motion 2500(Kbit/s)

0

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1000

1200

1400

1600

0 500 1000 1500 2000 2500 3000

Packet #

Pa

ck

et

Le

ng

th (

bit

s)

Figure 3.9: Shows the packet length variability during a medium motion clip through HD at a dialing speed of 2500Kbit/

Average packet length per dialing speed SD

0

200

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800

1000

1200

1400

0 100 200 300 400 500 600 700 800 900

Dialing speed (Kbit/s)

Ave

rage

pac

ket l

engt

h (b

its)

Medium motionLow motion

Figure 3.10: Shows the average packet lengths of low and medium motion clips per

dialing speed

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Average packet length per dialing speed HD

0

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1000

1200

1400

1600

0 1000 2000 3000 4000 5000 6000

Dialing speed (Kbit/s)

Aver

age

pack

et le

ngth

(bits

Medium motionLow motion

Figure 3.11: Shows the average packet lengths of low and medium motion clips per

dialing speed

3.1.3. End-user Quality of Experience

The Mean Opinion Scores (MOS) values that quantify end-user QoE in this report are broken up into two different categories: subjective and objective. Test were performed using both HD and SD equipment in three different network conditions: good, acceptable, and poor. The reader is referred to Table 3.1 for definition of network conditions defined by [32]. The setup used was identical to the setup used to obtain the traffic characteristic shown in Figure 3.1. The tests were performed using the network emulator to shape the traffic into the characteristics shown in Table 3.1. To obtain the subjective values, a group of test subjects were exposed to the original clips, low, medium and high motion, and then asked to watch the same clips running through VC units in different network conditions. Rating each on a scale of 1-5 where, 1-3 range is unusable to poor with frequent faults, 3-4 range is considered acceptable with few faults, and 4-5 range is deemed good with very few if no noticeable faults. The same network and rating standards were applied when obtaining the objective measurements. The objective measurements were taken using the NTIA VQM software that compares original and processed clips and searches for a variety of faults and provides an objective MOS value.

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Table 3.1: Network conditions configured on network emulator for MOS testing Delay

(ms) Jitter (ms)

Loss (%)

Good Network

80 5 0

Acceptable Network

200 25 .5

Poor Network

450 60 1.5

Table 3.2: Network bandwidth provisioned for MOS testing

HD (Kbit/s)

SD (Kbit/s)

Good Network

3000 960

AcceptableNetwork

2500 768

Poor Network

1250 400

The results echoed what would be expected. The low motion clip performed the best under all three network conditions on both SD and HD, with medium being rated second best. Comparing the two systems with both objective and subjective MOS measurements it can be concluded that in both good and acceptable network conditions the HD performed better, this as shown in Figures 3.12, 3.13, and 3.14.

SDVC Subjective MOS

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

Poor

Acceptable

Good

Ne

two

rk C

on

dit

ion

s

Average MOS

High Motion

Medium Motion

Low Motion

Figure 3.12: Subjective video performance of SD at a dialing speed of 768Kbit/s in

Good, Acceptable, and Poor network conditions.

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HDVC Subjective MOS

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

Poor

Acceptable

Good

Ne

two

rk C

on

dit

ion

s

Average MOS

High Motion

Medium Motion

Low Motion

Figure 3.13: Subjective video performance of HD at a dialing speed of 2500Kbit/s in

Good, Acceptable, and Poor network conditions.

Objective MOS of Low motion clip

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Poor

Acceptable

Good

MO

S S

core

Network Condition

SDHD

Figure 3.14: Objective MOS of low motion clips in good, acceptable, and poor

network conditions. The SD stream was run at 768Kbit/s and the HD stream was run at 2500Kbit/s.

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3.1.4: Performance conclusions

1. HD provides a better user experience at good and acceptable network conditions while in poor network conditions HD and SD have similar performance.

2. SD and HD behave differently in packet size configurations at different dialing speeds. At lower dialing speed SD adapts a larger/slower transmission scheme while HD opts for a smaller/faster approach.

3. SD and HD have different bandwidth usage approaches when different amounts of motion are present in the clip. SD tends to consume different amounts of bandwidth for different clip motions (e.g. less bandwidth consumption for low motion clips) while HD does not make any distinction.

The data here suggests that HD has a performance advantage to SD under good and acceptable network conditions as illustrated by the MOS measurements of both systems. This advantage is lost when suboptimal network conditions are imposed i.e., by letting the network conditions into poor grade. Observations from the clips were that in these situations the HD picture did exhibit more detail than the SD clip but were prone to more faults such as tailing and section shifting. The objective MOS caught this by ranking the two clips close to equal. Conclusion drawn is that with good and acceptable network conditions, HD is the better choice of the two. One note to make though is that - HD has higher expectations for network conditions than SD under similar conditions. Therefore if the increased network conditions cannot be met, there is no real QoE performance advantage when running HD.

The two systems take a different approach when placed at the same dialing speed. At a dialing speed of 768Kbit/s, which is the high end of SD and low end of HD, the two systems take different approaches with regards to handling the transmission packet sizes. At this speed, the SD structures its packets larger and transmits them slower with a larger inter-packet time than does HD. This can be shown in Figure 3.7 and 3.8. The largest noticeable difference between the two is the amount of bandwidth used in normal operating procedures. Examining Figures 3.5 and 3.6, we can see that HDVC is capable of using a significantly increased bandwidth than SD. Also shown by the traffic characteristic data is that - simply reducing motion will not lower the bandwidth usage of an HD system. This bandwidth consumption cannot be ignored in a practical sense and would not be advisable for users who cannot provide the needed extra bandwidth to switch from SD to HD. This is because the QoE testing shows that HD does not perform better than SD with a restricted bandwidth and network conditions. However with increased access to bandwidth, HDVC will run into less and less hindrances. It is currently being used already with large companies, research institutions and hospitals that have access to the needed bandwidth as explained in Section 3.4 of this report.

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3.2. Security We now look at three different Firewall/NAT traversal solutions including Cisco PIX with “H.323 fixup”, Polycom V2IU device, and GNU Gatekeeper. We utilize websites, manuals, and common topologies to analyze Firewall/NAT solutions.

The problem with security arises because firewalls and NAT devices, necessary in modern networks, either block or make traffic between the two VC endpoints not routable. A standard firewall such as IPTables, Cisco PIX without “H.323 fixup”, or a multitude of others rely on a packet’s header, specifically source and destination IP addresses and port numbers in order to make decisions to allow or deny through to their respective end-points. The firewalls rule-set relies on the system administrator selecting which services i.e. ports allowed to pass to hosts on the network. An example being a web server that needs to be open to the outside network to serve a web page. The system administrator would place a rule in the firewall that would allow anything destined for port 80 to the web server to pass. This works the same way with H.323 traffic. The two VC end-points first talk to each other establishing a connection using the H.225 and H.245 protocols that pass on a well known port, usually 1720. This works well with firewalls because it is known in advance what port the connection message will be destined. The problem arises during this control exchange when two VC end-points negotiate port numbers between 210 and 216 that they will use subsequently to transmit video and audio streams. The firewall will then block the incoming packets on these negotiated ports because it has no prior knowledge of the connection.

A NAT device poses a slightly different but no less problematic situation when dealing with H.323 traffic. A NAT device is implemented in networks to handle network address translation allowing for a single public IP address to be shared among multiple computers. It does this by translating incoming message destination address to one of a set of private IP address corresponding to a particular host. For example consider two VC units one in front of and one behind a NAT device. The NAT device has an outside address of 000.000.000.000 and the VC unit has a private address of 192.168.1.100. VC unit on the outside network attempts to call a VC unit on the inside by dialing 000.000.000.000, the address it believes the inside unit is located. The control message is allowed to pass and is translated to 192.168.1.100 because as with the firewall it is known beforehand what to do with H.225 and H.245 messages. The problem arises again when the subsequent transmission ports are negotiated. The inside unit believes that its address is 192.168.1.100 and therefore instructs the outside unit to transmit voice and video data to this address at the negotiated ports. All messages transmitted to 192.168.1.100 are therefore not routable and never reach the inside unit.

The following three sections are dedicated to the three common solutions in modern networks to solve the problems created by firewall and NAT device implementation.

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3.2.1. GNU Gatekeeper The GNU gatekeeper (GNUGK) is a free open source program developed in the OpenH.323 project. The GNUGK is distributed and maintained by http://www.gnugk.org which also holds all the documentation and links supporting development and implementation. Able to run on all of the major operating systems, Linux, Windows, FreeBSD, Solaris, and MacOSX, the GNUGK is versatile enough to be implemented in a variety of different environments [30]. GNUGK is able to run on machines with modest specs when operating with basic functionality such as a connection establisher. Therefore, it is a low priced option for E.164, GDS number options. In the more complex functions mode, the speed of the deploying system needs to increase accordingly. Running GNUGK in more advanced modes such as proxy usually requires a server grade system to minimize effect on VC performance. Though the program is distributed with many functions; the proxy capabilities are what allows GNUGK to be used as a traversal device and is the function this report is interested in. The GNUGK solution entails placing the machine running the gatekeeper to be placed in the “demilitarized zone” (DMZ) on the network front end. The diagram of this is shown in Figure 3.15. The DMZ is a logical side area where packets can be routed first without being scrutinized by the firewall or translated by the NAT device. GNUGK running the proxy function has the ability to route relevant data around the firewall and NAT device therefore eluding the negative results without opening up the network to intrusion. By configuring the firewall to allow the gatekeeper to tunnel data through, it does not need to know the H.323 ports beforehand. This solution allows all but VC traffic to be handled by the firewall and NAT without intrusion, thus keeping the integrity of the security system. VC endpoints use the gatekeeper by engaging in a few different steps to ensure the correct routing of data. First the VC endpoint inside the protected and translated network must registers with the gatekeeper. If need be, the gatekeeper can issue a E.164 GDS number to distinguish it when more then one end-point is present. A system on the outside of the network then calls the unit it wants by dialing the outside IP address. This signal gets routed to the gatekeeper who runs through the motion to establish the connection between the two units. It then acts as a gateway between the two units tunneling the data between the two, diagram shown in Figure 3.15.

Figure 3.15: Shows diagram of GNUGK firewall/NAT traversal solution.

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The GNUGK working on smaller loads cost significantly less then the either the V2IU or PIX “H.323 fixup”, though as the load increases the cost rises with the needed hardware. One of the best advantages the GNUGK provides is that - it allows system administrators to continue using their current configuration with minor changes. The disadvantages with this approach are its cost to the overall system performance and security concerns. Given that the GNUGK acts as a proxy forwarding all of the data between the two endpoints, it introduces an element of delay. This can be a significant factor in high volume systems or when there are multiple calls running through the same gatekeeper. The other disadvantage is the slight cost to security. Because the GNUGK must sit in the demilitarized zone it has access to the inside of the network, therefore if the system itself is compromised then so is the network. This means that the machine running the GNUGK needs to be hardened itself with regular maintenance and monitoring necessary to ward against attacks. There effect of HD in particular is not well known and research is being done in that area. Looking at the MOS values, it is clear that if the GNUGK system is not able to handle that traffic load associated with HDVC than you will see a significant penalty. If the GNUGK’s system impact can be contained to reasonable values, it would certainly be an attractive solution. 3.2.2. Polycom V2IU solution The solution developed by Polycom is a variety of units dubbed as the V2IU systems. As of the writing of this report, they come in three different varieties: the S, E and traversal units. The E units are designed for enterprise application and are able to handle heavier loads then the normal traversal units. The S series are designed to be used in situation where scalability with multiple units is a higher priority. While the traversal unit is consumer grade, it is good for small firms with a lower traffic volume. Each of the different series of units provides a different set of functionality and level of performance but all are capable of firewall and NAT traversal which is the function this report is interested in. The V2IU units are self contained therefore do not need a host system in order to implement its functionality. The system is usually situated at the front end of the network and works as a barrier between two or more networks. The units themselves provide firewall and NAT capabilities with an embedded SPI firewall [26]. The unit then can act as a substitute for the traditional firewall, NAT unit, eliminating or reducing the need for redundant systems. The traversal solution implemented by the V2IU system is based on its internal gatekeeper and uses the H.460 tunneling protocol. The H.460 standard has a couple of different modes, with H.460.18 being the relevant protocol to this report. The H.460.18 signal is an extension of the H.323 standard enabling it to allow H.323 traffic to transverse firewalls and is applicable in NATed environments [26]. As stated earlier a H.323 session requires the use of many different connections, such as the H.225 and H.245 connection establishment and the multiple UDP real time protocol (RTP) streams that carry the content data. The H.460 standard traverses the firewall and NAT devices by allowing for the unit behind them to initiate and therefore establish the connections. By making these changes to the H.323 standard the firewall problem is circumvented

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because by having the private side unit initiates the connection the firewall is therefore aware and will allow the data to pass. The same reasoning is established when traversing NAT devices, by allowing all messages to be established by the private side host the subsequent data traffic is translated to the correct destination.

Figure 3.16: Shows diagram of V2IU firewall/NAT traversal solution

Though dependent on the situation at which it is being deployed, the V2IU system is usually placed at the front end of a LAN or subnet. In larger networks or in the case of an MCU it may be necessary to place the V2IU in the DMZ of the networks firewall and configure the firewall to allow for H.460 tunneling [31]. The V2IU systems embedded gatekeeper then acts as the proxy for all the H.323 units behind it. This allows for a range of different calling structures including IP, E.164 GDS and a new feature that allows calls to be placed by email address [31]. This gives the V2IU the added capability of creating a neat and organized call structure. The main advantage of the V2IU systems is that it can be implemented into almost any network without compromising security or requiring the purchasing of multiple IP addresses. The V2IU system is also relatively easy to configure and is a supported solution unlike the GNUGK. This combined with the many different models also makes this an attractive option for small firms that don’t need the power of say the PIX system described in the next session. The disadvantage associated is there may be issues of performance if the traffic load reaches to high a level. It also is not intended to be used with other traversal solutions, including “H.323 fixup”. Like the GNUGK, the V2IU has the potential to be a complete and attractive solution for HDVC security if the penalty of implementation can be kept to a minimum. Future research of its effects with the different units will show if it is a viable solution. 3.2.2. Cisco PIX firewall with “H.323 fixup” The Cisco PIX firewall is an enterprise grade firewall and NAT device that is deployed manly on large corporate, governmental, or educational networks. Being the most expensive of the three solutions covered in this report costing around $30,000+ it is impractical for small firms that do not have large traffic demands. What makes this system interesting to VC users and network administrators is its ability to host the “H.323 fixup” routine, an attractive solution to larger firms.

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The functionality that makes it possible to use H.323 devices with the PIX units is the “H.323 fixup” software that can run on the PIX itself. The “fixup” software has two major functions; to transverse NAT and to opening the needed media channels. To do this the system administrator must open the well known port 1720 for H.323 connection establishment and tell the PIX that H.323 traffic will flow through this port. Hence, the PIX will then know to implement the “H.323 fixup” on that traffic. The PIX transverses NAT situations by examining the H.323 control messages namely H.225 and H.245 and applying the need address translation [28]. The second function of the “fixup” software is to dynamically allocate the needed control and data messages to allow for the H.323 traffic to pass. This is done by inspecting the H.225 signal channel and obtaining the information about the upcoming H.245 signals. Each subsequent H.245 signals is run through the NAT translation. Also the “fixup”, after inspecting the control signals, dynamically opens the necessary channels in the firewall to accommodate the incoming and outgoing voice and video streams.

Figure 3.17: Shows diagram of Cisco PIX “H.323 fixup” firewall/NAT traversal

solution The advantage to this system is that it is a robust implementation on a robust platform. The idea is that it should do little if any noticeable difference in the systems performance. The downside being that it is an expensive and complicated system that really should only be used in large environments and require a qualified administrator to configure. The PIX system shows the best promise for being the most compatible to HDVC because it is the most powerful of the three systems. Research into its effects on the quality and usability of the “fixup” on HDVC traffic will show its compatibility. 3.3. Collaboration We looked at collaboration tool vendor websites to look at the different features of common collaboration tools. We also compared the cost of the various collaboration tools. We were also able to use a report by other researchers about collaboration tools.

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We built contacts that included experts and everyday users of collaboration tools. The results of the collaboration tool research are documented in Appendix II. Recall from Section 2, Tables 2.2 and Table 2.3 show the comparison of features and suggested use of the popular tools to data. The future of these tools is to integrate HD video, images and advanced control. One promising application of this technology is in the area of advanced instruments control and research collaboration. The idea is that a single high powered microscope with a scientific sample may be viewed by researchers around the world. The advantage of HD video in this application would be that the capabilities of the advanced instruments would not be degraded by the quality of video. This would allow for doctors of different specialties in different location to look at the same sample concurrently improving diagnosis and patient care as one example. There are many other domains that would be improved by the integration of HD video into collaboration tools. An example of domains that would benefit from this technology included video and image production, engineering, military and research. These factors will push research and development into this area. 3.4. HDVC Applications 3.4.1. Health Care

Doctors and nurses could use HDVC for the diagnosis of patients and training

purposes. They could better diagnose remote patients without access to a specialist with the use of HDVC [6]. Yet using videoconferencing for medical assessments could allow for intruders to view the video feed [6]. This creates an issue for doctor-patient confidentiality [1]. Doctors and nurses could even learn new procedures with the detailed video that HDVC broadcasts to its viewer. The University of Minnesota is installing HDVC equipment to allow medical students to view X-rays and MRIs. This will train them to identify abnormalities within these X-rays and MRIs from cases anywhere around the world. 3.4.2. Education

A child’s school experience could be enriched by HDVC [7] [9]. HDVC would

allow these students to learn about things like different species of fish more effectively. They can clearly see the scales and fins of each fish using HDVC. Students will get the sense of “being there” on HDVC field trips [9]. School districts could even offer classes over HDVC to students without them being physically present. In St. Clair County, Michigan, students can take classes like foreign language and advanced placement using VC equipment. They even have VC field trips for students across the county.

The Center of Excellence for Remote and Medically Under-Served Areas (CERMUSA) worked with a program that taught American Sign Language over SDVC equipment. When using the SDVC system, they had to use a dark background to make their signing discernable. HDVC would be a great benefit to student understanding of sign language. When using American Sign Language, you need to be able to clearly see the motions and hand gestures of the person on screen. A HDVC system would allow for a much better video quality than a SDVC system to accomplish this.

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Music instruction could be better delivered over HDVC. Music students from Ohio could be instructed by the best teacher in the country that lives in California using HDVC. The instructors would be better able to see if they have the correct finger placement on their violin strings. Music schools like Cleveland Institute of Music and New World Symphony are already using HDVC to benefit instruction of their students. Videoconferencing is becoming so important to the business world that business colleges are putting it in their curriculum [10]. This demonstrates that many businesses are using VC systems that need dedicated staff to maintain. 3.4.3. Judicial Some courts are now using videoconferencing systems to arraign prisoners from jail [1]. This reduces the transportation costs for the state or county. It also helps decrease the security needed in courthouses. In St. Clair County, Michigan, they offer GED courses to prisoners over videoconferencing equipment. We believe that this idea will become more common in jails in the future. It will give prisoners a chance to turn their lives around after they are released from prison. It is more likely that they will find employment with a GED than without one. 3.4.4. Business Businesses use VC systems for meetings, training, and interviews. Different branches of a company from all over the world can collaborate of a VC system, thus saving travel costs. Training new employees can even be accomplished by one trainer broadcasted to many branches. Companies are even able to realistically interview an applicant with HDVC. Other methods of communication would not give an employer the necessary impression needed to hire someone compared to the clear video from HDVC. 4. The Future for HDVC

In time, we envision that HDVC will become the standard in communication. HDVC has many promising possibilities for the future. Many fields could benefit from the use of HDVC such as, judicial, education, health care, and emergency applications. For example, an emergency response team could be available to contact through your videoconferencing equipment in the future [1]. Emergency care units could analyze patients using HDVC systems so that responders are able to administer the appropriate care faster. HDVC system would allow them to see the patents injuries clearer than on a SDVC system allowing for a better diagnosis. Therefore, they could give patients a better chance of survival and effective treatment. If HDVC becomes as common place as the telephone, it will make emergency care through HDVC easier to accomplish.

HDVC could benefit insurance companies in the future. Instead of sending employees to check claims on cars, they could use HDVC to look at the claims from the mechanic shop in high detail. They would be able to come to a conclusion about the car without having to leave the office. The travel costs for insurance companies would be reduced by the use of HDVC system.

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In the future, prisoners could participate in their trial purely through a videoconferencing system from jail. Judges and juries use the reactions and body language of the defendant in their deliberation. The use of a HDVC system could allow for judges and juries to still factor in these reactions because of its high quality video feed. The defendant’s rights to participate in their trial would still be upheld with the use of HDVC. The costs of transporting prisoners would greatly diminish. It would even decrease the need for security in the courthouse. Cisco’s TelePresence system could greatly benefit this application because it would give the participants a very realistic view of the court room. TelePresence makes each VC room have the same wall color and carpet along with three displays. This high definition system seamlessly creates the illusion of being in the same room.

Social applications of HDVC will become more prevalent in the future. It will be like facebook and YouTube in its purpose. The online VC of today like Skype will become obsolete with their poor audio and video feed. HDVC will give a more realistic aspect to chatting with friends and family. Relationships will be better maintained with the use of HDVC. Collaboration tools will be useful in social applications like sharing photos with friends and family. Even getting help on homework by a friend or relative on HDVC could be easily accomplished using the application sharing feature on collaboration tools.

Collaboration tools will be integrated into HDVC in the future. Therefore, HDVC will be able to give a better VC experience. Businesses will easily be able to give presentations through HDVC with the use of collaboration tools. More and more business are having employees participate in virtual groups. The members of these virtual groups could be from branches of a company all over the world. Virtual groups will easily be able to work together on reports and presentations with the help of application sharing. Virtual groups work better with quality communication between members, which can be made possible with HDVC.

Firewalls/NAT will become less of a problem for video feed with the improvement of existing solutions and the design of new solutions. This will allow for video traffic to be sent over a network without hiccups caused by Firewalls/NAT. Eventually, complex encryption technologies may become so important that manufacturers would consider including them in their codec designs. Thus, the HDVC equipment will be secure from invaders from the first moment of operation.

In time, high definition screens will become immersive, e.g., they will be built into room walls for convenience. A wall-sized screen will allow for a more life-like experience. A HDVC system will eventually be found in almost every household and business worldwide. The usability and reliability will continually improve with familiarity and consequently costs will reduce to purchase the HDVC systems.

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5. Conclusions

The shift to high definition video is beginning in the U.S. Videogames, movies, and television are all making the change to high definition video as the new status quo. The movement has found its way to videoconferencing. High definition videoconferencing gives its audience clearer images compared to standard definition. It allows for easy and fast communication between people, with the ability to show the detail of body language or presentations. At this stage of the technology’s development, given current network infrastructure and display technology, questions have been raised on its reliability and usefulness.

A hindrance is the high costs of HDVC systems, which are a major concern with possible buyers [5]. The difference in cost between a HDVC system and a SDVC system is significant, especially considering that HDVC displays cost much more than SDVC displays. Many organizations are willing to pay the price for HDVC because it gives a more realistic experience of being in the same room, and the ability to show greater detail. The convenience and usefulness of high definition video keeps this technology in demand from many application domains. Future competition and technological development will cause the cost of HDVC to go down like most technologies.

The networks in which HDVC will be used must be able to handle the increased load of high definition streams. One focus of this research is to determine if there is a significant difference in the needed network capabilities between the SD systems and the HD systems. It is shown by the traffic characteristics that HD does need more bandwidth than SD. Yet with slight improvements to network infrastructure comes a jump in video performance when using HD. This leads to believe that HDVC is a viable and reliable solution. With the right network and security setup, HDVC is posed to become a useful and reliable tool in several application domains in our society. 6. Acknowledgements We would first like to thank the American Distance Education Consortium for providing this excellent NSF sponsored REU opportunity. We would also like to thank the Ohio Supercomputer Center for letting us use their facilities and equipment. We would like to thank Nathan Howes for helping us with our network problems and for participating in our experiment. We would like to thank Terry Lewis, David Kehrle, and Kenneth Fox for helping us procure VC equipment to test. We would also like to thank Arif Khan for helping us build contacts and for his advice. We would like to thank Abdul Kalash for participating in our experiments and for his help with the NTIA VQM software.

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7. Bibliography [1] “Videoconferencing Cookbook.” VIDe. March 2005. <http://www.vide.net/cookbook /cookbook.en/>. [2] Ou, George. “Is High Definition video conferencing worth it?” ZDNet. 4 May 2006. <http://blogs.zdnet.com/Ou/?p=207>. [3] “High-Definition: The Evolution of Video Conferencing.” Polycom. 1 June 2007. <http://www.polycom.com/common/documents/whitepapers/high_definition_the_evolution_of_video_conferencing.pdf>. [4] Golston, Jeremiah. "HD- Taking Compression into Account." Texas Instruments. <http://blogs.ti.com/2006/08/13/hd-taking-compression-into-account/>. [5] Van, Jon. “Videoconferencing goes high-definition.” Chicago Tribune. <http:// www.chicagotribune.com/business/local/monday/chi-0705112129may14,0,3805698. story?coll=chi-businessmonday-hed>. [6] Guilfoyle, Clare, Richard Wootton, Stacey Hassel, Jann Offer, Margo Warren, and Debbie Smith. “Preliminary experience of allied health assessments delivered face to face and by video conference to a residential facility for elderly people.” Journal of Telemedicine and Telecare, Volume 9, Issue 4. 1 August 2003. OhioLink. <http:// journals.ohiolink.edu/ejc/pdf.cgi/Guilfoyle_Clare.pdf?issn=1357633x&issue=v09i0004&article=230_peoahaarffep>. [7] Boxel, Patris van, Keith Anderson, and Claud Regnard. “The effectiveness of palliative care education delivered by videoconferencing compared with face-to-face delivery.” Pallative Medicine, Volume 17, Issue 4. 1 June 2003. OhioLink. <http:// journals.ohiolink.edu/ejc/pdf.cgi/van_Boxel_Patris.pdf?issn=02692163&issue=v17i0004&article=344_teopcebvcwfd>. [8] Videoconferencing Insight Newsletter. <http://www.vcinsight.com/>. [9] Richards, Erin. “Learning in high definition.” JSOnline. 25 April 2007. <http://www. jsonline.com/story/index.aspx?id=596494>. [10] Hildebrand, Janet E. Journal of Business and Technical Communication, Volume 9, Issue 2 April 1995. OhioLink. <http://journals.ohiolink.edu/ejc/pdf.cgi/Hildebrand_ Janet_E.pdf?issn=10506519&issue=v09i0002&article=228_vitbc>. [11] “The End of Analog.” Sony Learning Center. <http://www.learningcenter.sony.us/ HomeAudioandVideo/Televisions/Research1/ExploreDigitalFormatsDTV>. [12] “Protocol and Codec Specifications.” Rutgers Academic Video Services. <http:// videoconference.rutgers.edu/protocol_specs.jsp#codec>.

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[13] “Supporting Real-time Traffic Preparing Your IP Network for Video Conferencing.” Polycom. <http://www.polycom.com/common/documents/whitepapers/supporting_real time_traffic_preaparing_ip_network_for_videoconferencing.pdf>. [14] “User Datagram Protocol.” Wikipedia. 15 June 2007. <http://en.wikipedia.org/wiki/ User_Datagram_Protocol>. [15] “High Definition Video Communications.” LifeSize. <http://www.lifesize.com/ products/lifesize_room/>. [16] “Sony PCS-HG90.” IVCi. <http://www.ivci.com/videoconferencing-sony-pcshg90. html>. [17] “TANDBERG Edge 95/85/75 MXP.” Tandberg. <http://www.tandberg.com/product /video_systems/tandberg_95_85_75_mxp.jsp>. [18] “Polycom HDX Series Features and Benefits.” Polycom. <http://www.polycom. com/common/documents/support/sales_marketing/products/video/hdx_features_benefits.pdf>. [19] “Advanced Video Coding on Linux.” Linux Journal. <http://www.linuxjournal.com /node/9005/print>. [20] “LifeSize™ Redefines Videoconferencing Industry with New High Definition Video Communications Products.” LifeSize. <http://www.lifesize.com/press/press_releases/ press_041805.php>. [21] “PCS-HG90.” Sony. <http://bssc.sel.sony.com/BroadcastandBusiness/Display Model?m=10010&id=83891&navid=pcs_hg90_high_definition_visual_communications_system>. [22] "Configuring Application Inspection (Fixup)." Cisco Documentation. 4 Nov. 2002. Cisco Systems. 31 July 2007 <http://www.cisco.com/univercd/cc/td/doc/product/iaabu/ pix/pix_62/config/fixup.htm#xtocid15>.

[23] “High Definition Video.” LifeSize. <http://www.lifesize.com/downloads/pdf/data sheet_room.pdf>. [24] "Internet World Stats Usage and Population Statistics." 2007. Miniwatts Marketing Group. 2 July 2007 <http://www.internetworldstats.com/am/us.htm>. [25] High Definition: the Evolution of Video Conferrencing. California: Polycom, 2005. 21 June 2007. [26] NOECA V2IU Briefing. Edgewater Networking Inc. 2006. 11 July 2006.

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[27] Calyam, Prasad, Nathan Howes, Weiping Mandrawa, Arif Khan, Steve Gordan, Gabe Moulton, Megan Troyer, Chris Hartley, Brian Morller, and Bob Dixion. Videoconferencing Via Firewall/NAT Using GNU Gatekeeper Proxy. Ohio Supercomputer Center. 2006. [28] Roberts, Jonathan. Integrating Cisco Secure PIX Firewall and IP/VC Videoconferencing Networks an IP/VC Application Note. 2001. 31 July 2007. [29] Welcher, Peter J. "Cisco PIX Firewall Basics." Cisco PIX Firewall Basics. Netcraftsman. 31 July 2007 <http://www.netcraftsmen.net/welcher/papers/pix01.html>. [30] "GNU Gatekeeper - a Free VOIP Gatekeeper for H.323." GNU Gatekeeper. 31 July 2007. www.GNUGK.org. 16 Aug. 2007 <http://www.gnugk.org/>. [31] Users Guide V2IU. Polycom. Appendix-H460. [32] Calyam, Prasad, Eylem Ekici, Chang-Gun Lee, Mark Haffner, and Nathan Howes. A "GAP-Model" Based Framework for Online VVoIP QoE Measurment. Ohio Supercomputer Center. [33] Ghandari., Prof. M., Prof D. Crawford, Dr. M. Fleury, Dr. E. Khan, Dr. J. Woods, Mr. H. Lu, and Mr. R. Razavi. Future Performance of Video Codecs. Video Networking Laboratory, Department of Electonic System Engineering University of Essex. 2006. [34] Griffin, Robert E., Dana Parrish, and Michael Reigh. Using Virtual Classroom Tools in Distance Learning: Can the Classroom Be Re-Created At a Distance? 2006.

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Appendix I: Annual Distance Teaching and Learning Conference – Trip Report

As part of the REU program, we represented ADEC in a booth at the Distance Teaching and Learning Annual Conference (DTLAC) in Wisconsin in early August. The conference website is - www.uwex.edu/disted/conference.We met with conference participants interested in high definition videoconferencing. They asked our opinion on standard definition versus high definition video, and which HDVC systems to buy.

We were able to talk to people in other booths. We talked to companies like Cisco, GED for me, NCast, Embanet, AMSER, and READI. Cisco talked to us about their high definition videoconferencing system called TelePresence. The bandwidth needed for one screen in the TelePresence system is 3000 Kb/s per screen with a typical system is 3 screens. The “GED for Me” program is meant for people to earn their GED using video streaming of prerecorded lectures online. Students are able to study for their GED from the comfort of their own home. NCast is a company that deals in selling equipment for video streaming purposes. They offer portable capture and distribution devices, servers, and practical presentation and collaboration devices. Embanet is a company that helps universities set up online courses and degree programs. They offer help with marketing, admissions, program management, help desk support, instructional design and course development, and faculty training and recruiting. AMSER is part of the NSF’s National Science Digital Library (NSDL). They allow everyone to access resources that deal with math, science, and engineering topics. Their website is - http://www.amser.org. These resources could be helpful in current or future research. READI is a tool that determines the probability that students will be successful in an online course. It looks at five aspects to measure their success including on-screen reading speed and comprehension, technical competency, individual attributes, preferred learning styles, and typing speed and accuracy. Wiki was the subject of two separate seminars. Wiki is a collaboration tool. This tool can create and edit shared content. This tool is helpful for students separated by time and space. Editing wars are common when using this tool. The solution to editing wars is to allow both sides a forum to voice their opinions. There are intruders who can change your page, which can be frustrating. The wiki software does allow you to see who has changed anything and what has changed on the website. The wiki chosen by one of the seminars was PB Wiki and allows for a group of people to create a report collaboratively. The presenter claimed that they had limited problems with the technology.

Another seminar dealt with virtual teams. Our presenter taught online accounting classes. She told us that businesses like to use virtual teams, but they tend to fail. She studied the virtual teams set up in her course to examine why these teams fail. Virtual teams seemed to work better the more they communicated with each other. They also needed to trust each other. This is accomplished by having some sort of social relationship with each other. I think that virtual teams would run much smoother with a videoconferencing aspect. It would be easier to establish a social relationship and a sense of trust.

II

Another seminar was about the University of Minnesota’s UNITE program. It is a program for graduate students to take online courses. They record the lectures and download them online for the students to watch. Distance students were even able to watch the lecture live if they wanted to. Students from across the country participate in these classes. They use UMConnect which is like AdobeConnect for distance students to give presentations for class. The presenter was even considering using UMConnect for team projects in his courses. The UMConnect would allow them to have face-to-face interaction to broaden their team experience.

Another seminar called streaming and webcasting technology assessment was available. When using these technologies for classes, there are concerns about student attendance and crashing the network. Students tried to look at the lectures all at once like before midterms, which crashed the network. Students didn’t seem to do better with the use of webcasting lectures and attendance was down. The psychological effect of having this technology was calming to the students.

The seminars in general were geared towards educators and administrators, but we still had a great learning experience. We concluded that there were several aspects of online courses that could benefit from HDVC coupled with suitable collaboration tools.

III

Appendix II: Features comparison of Collaboration tools Vsee

Description: Vsee is a Windows based peer to peer collaboration tool developed by the Vsee lab which was founded in 2003 and funded by the National Science Foundation. Vsee is videoconferencing software that strives to use a low bandwidth though providing high quality video. Vsee allows between 3 and 6 simultaneous individual video chats, depending on bandwidth and computer speed. Also available with Vsee is the ability to annotate and edit documents, application and desktop sharing, and transfer files. Security is also taken into consideration with Vsee, using 256 bit encryption. Main Use: The Vsee system is good for small meetings of a few people working on collaborative project. The product claims to provide high quality video for microscopes and white board cameras and also provided a reliable, secure means of communication for important communications. Given the reliability and security, it has been chosen for use by such groups as U.S department of defense, Intel, and others. Requirements: Requires a broadband Internet connection, Windows operating system (Vista not supported as of writing this report), Camera. System strength dictates performance and the number of concurrent users. Cost Structure: Vsee offers their software in a couple of different ways, a professional version and a scientific version. The professional version is free for in enterprise and consumer use. A $39 a month version is available for cross enterprise calls and also adds features such as call to telephone, SMS to telephone, and 24 hour support. The software can also be privately deployed on an institution’s server for $99 a concurrent user up to 1000 users. The scientific version is available through contacting Vsee Company directly.

IV

Recommended Use: Good for small teams working on collaborative projects, such as software development. Sources: http://vsee.com/index.html : http://vsee.stanford.edu/wall/

Skype and Skype + Unyte

Description: Skype is an Internet calling tool that works off of a peer to peer architecture. Skype allows users to place voice and video calls with voice conferencing calls for up to 9 people. Along with voice and video calling Skype allows for individual and group text chats as well as file transfer capabilities. Unyte is a program that can be added onto Skype to add additional functionality. With Unyte free version desktop viewing is added which allows users to display their desktop. Unyte also has a purchase version called Unyte+ that adds; annotation, pointer, desktop and application sharing capabilities. Main Use: Skype itself is used as a social networking tool that allows communication between friends and family, though it can just as easily be used as a communication tool for coworkers. With the Unyte add-on, more of a work-collaboration feel and functionality is introduced. Using a paid version, small meetings can be setup. Requirements: Skype is compatible with Windows, Mac, and Linux, with speed of machine dictating performance. For the Unyte add on Windows and the appropriate plug-in is required (Minimum: 1 GHz CPU, 256MB RAM and broadband Internet). Voice and video require camera, microphone and speakers.

V

Cost Structure: Skype is free to download and use when calling Skype to Skype. Extras such as Skype to phone calls and SMS messages cast approximately $29 an month for unlimited calls and between 3~10 cents per SMS message. Unyte has two versions free and a paid version. The paid version cost between $30/year for a host and one viewer to $450/year for a host and 24 viewers. Recommended Use: Skype is the standard for voice calling across the Internet and with video and chat functions good for one on one communication. With the Unyte add on small to mid size meetings become possible. Sources: http://www.skype.com/ : http://www.unyte.net/ Evo

Description: Evo is a tool written in Java and accessible across platforms assuming that java is installed on the machine. Using the Evo client (kuala), users are able to join meetings using audio, video and text chat communication tools as well as a virtual white board and file exchanging. This is made possible using an intermediate server called Panda which establishes the connection between Evo members. To access Evo, first a user needs to register with the panda system from Evo's web page. Then the user is able to start the client program from the same page and proceed to make calls. Meetings can be held in point to point or by multipoint. Inside the meeting, users have access to all the features provided by Evo as well as private text and audio chat within a meeting. The client is also compatible with H.323 and SIP protocols, making a versatile system. Main Use: Evo was designed as a cross platform way for the scientific community to collaborate. Requirements: Windows, Linux, or Mac with 1.5 GHz processor and 512MB RAM for Intel processor and 1 GHz and 512MB with power PC processor. The Java runtime environment is also required.

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Cost Structure: Free Recommended Use: Ad-hoc meeting structure may be used to facilitate study groups and information sessions. Sources: http://evo.caltech.edu/

Groupworld

Description: Groupworld is a cross platform, client-server type conferencing solution. Groupworld provides an online meeting space in which users can log in and participate in voice, video and text chat as well as use a virtual white board and desktop sharing. The service can hold up to 10 users when using a hosted service or 25 users when privately hosted. This service can be expanded using custom licensing agreements. It is currently being used in tutoring situation by a verity of groups. Groupworld works using a plug-in to common web browsers such as Internet Explorer, Firefox, Safari, Netscape, and Mozilla. The meeting room is set up on a web server and is accessed by a URL link which participants use to enter meeting. There are two ways this can be achieved, using Groupworld's hosting service or installing the software onto a private server. Main uses: It is being used currently to host online tutoring sessions, and online schools. Also it is being deployed as an Internet conferencing space for a variety of different companies. Requirements: Groupworld works with all major browsers with available plug-in. A broadband connection to the Internet is needed. Cost Structure: The hosted solution allows for unlimited use with up to 10 concurrent users for 29.99 a month. Or a permanent license can be purchased for $999, run on private server. This solution allows for 25 concurrent users. Custom licenses are available.

VII

Recommended Use: Grourpworld is well adapted for online learning applications such as classes and homework groups. Sources: http://www.groupworld.net/

Acrobat Connect

Description: Acrobat connect is an online presentation and meeting space hosted by Adobe. It works based on client-server type architecture. There are two versions offered: Acrobat connect and Acrobat connect pro. Acrobat connect allows users to sign in to online meeting rooms, which can handle up to 15 concurrent users who are able to participate in voice, video and text chat. Also available is white boarding and annotation tools. The presenter also has the ability to initiate application and desktop sharing. This creates a virtual meeting room on the Internet where members of a group can convene. Acrobat connect pro adds to Acrobat connect a lot of features including; file transfer, rich media support, polling, and recording functionality. Main Uses: Adobe Connect in educational use is aptly suited for online classes and scheduled tutoring sessions. In business it is well suited to give sales presentations and hold meetings. Requirements: Required is a compatible web browser; Firefox, Internet Explore, Safari, or Netscape with Flash player 8 or 9. Also required is a broadband Internet connection.

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Cost Structure: Acrobat Connect gets one meeting room for $39 a month. Acrobat Connect Pro ranges from $375-700 a month for multiple rooms. Recommended Use: Good for business meetings, sales presentations and could be well suited for online classes. The presenter audience structure may cause a problem for ad-hoc meetings. Sources: http://www.adobe.com/products/connect/ VNC

Description: VNC is a simple desktop sharing program. Users can log into machines that have a VNC server running and are able to control the remote desktop. Main uses: VNC allows IT personnel to fix problems in servers and other systems using graphical user interfaces, making work easier. It also allows for giving support to users and customers through the Internet Requirements: Internet access and a VNC client and server

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Cost Structure: Free Recommended Use: Good for IT and has its uses for assisting people with computer issues through the Internet. Not so good for meetings. Sources: http://www.realvnc.com/ : http://www.tightvnc.com/ Gizmo

Description: Gizmo is an Internet telephone and instant messaging program that allows users to connect with many different voice and IM clients. Users of Gizmo are able to call Google talk, Windows live, and Yahoo messenger. Gizmo also has the ability to have one on one or group chats with a variety of different clients. Gizmo has the ability to participate in conference calls with the number of people dependent on the bandwidth. All functions are carried out using a buddy list similar to traditional chat programs; Gizmo is also compatible with SIP. Main Uses: Gizmo works well as a general Internet networking tool with the ability to make voice calls. Designed as a computer telephone and is capable of calling out to both standard and model phones. Requirements: Works with Windows, Mac and Linux

X

Cost Structure: Free for most uses, pay to place or receive calls from traditional or cellular phones. Call out prices are approximately 2 cents a minute while call in is $12 for three months or $35 for a year. Recommended Use: Good consumer product, useful for general communication. It lacks functionality to have high level collaboration meetings. Sources:

http://gizmoproject.com/

MSN Messenger

Description: MSN Messenger is an instant messaging program that is available on the Windows operating system. Besides the traditional instant messaging, Windows Live Messenger also allows for voice and video conversation with file transfer. It is similar to AIM and Yahoo messenger. Main Use: Its main use is as an instant messaging client allowing for general conversation and simple collaboration through file transfer. Requirements: Windows

XI

Cost Structure: Free, except when calling modal or traditional phones which costs ~2 cents a minute. Recommended Use: Good program but lacks functionality for meetings Sources: http://get.live.com/messenger/overview

I-Linc

Description: I-Linc is a high end provider of web conferencing. The company has geared their software suites to meetings, conferences, customer support and online learning. Backed by a 24 hour customer service and technical support I-Linc is a reliable service. I-Linc has two options either hosted, where the server is provided and maintained by I-Linc or installed that use a private server. The service is accessed using an I-Linc client installed on the local machine I-Linc provides a broad range of functionality including voice and video chat, white boards, application sharing, shared browsing, polling, question and answer, electronic hand raising, participants list, text chat and a variety of administrative controls is available Though not every function is available on every version of the program. Main Uses: Used by large firms to hold meetings, conferences, provided training and customer support. Requirements: It requires Windows operating system with compatible web browser, client installed and a broadband connection to the Internet. Cost Structure: $54,870 a year for a 30 seat licenses. [1] Recommended Use: It is recommended for large firms and agencies. Sources: http://www.ilinc.com/

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Microsoft Live Meeting

Descriptions: Live meeting is a fully functional meeting and conferencing environment developed by Microsoft. Meetings are hosted by Microsoft and can be entered either directly or though Microsoft Messenger providing the functionality such as application and desktop sharing, remote control, virtual white boards, annotation tools, chat, question manager, polling, as well as an innovative seating chart and mood indicator. The mood indicator allows for participants to expresses there opinion on such things as the speed of the meeting and quality of the content. Main Use: Used for business collaboration and web conferencing. Requirements: Windows operating system and Internet explore or Mac with Safari and at least a 56k Internet connection Cost Structure: There are three main ways one is by named users which cost $180 per user per year for standard version and $300 per year per user for the professional, in addition to a $3000 annual fee. The second option is to buy a room which costs $12000 a year for standard and $20000 a year for professional, plus a $3000 annual fee. Recommended Use: Large firms and agencies. Sources:

http://office.microsoft.com/en-us/livemeeting/FX101729061033.aspx

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WebEx

Description: WebEx is a high end, feature laden web conferencing provider geared toward business communication with services for individuals, and small and large businesses. WebEx is tailored to providing web conferencing tools such as application and desktop sharing as well as text chat, voice and videoconferencing. Like most high end conferencing tools it can be hosted by the company or managed in house by the user. Connection to the service requires only a browser and an Internet connection. Main Use: Business collaboration Requirements: A web browser and a telephone connection Cost Structure: Contacting WebEx. Recommended Use:

It is recommended for large firms and agencies. Sources: http://www.webex.com/

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Horizon Wimba

Description: Horizon Wimba is an online learning platform developed to provide a classroom feel. Providing all the features of a high end system, including voice, video and text chat as well as participants list, application sharing, polling and recording capabilities. Innovative features allow Horizon Wimba to be integrated into CMS programs such as blackboard. Horizon also provides hosting services with 24 hour support. Main Use: Virtual class room and presentation environment Requirements: Works with Windows, Mac and Linux provided having java runtime environment installed and compatible web browser. Cost Structure: 19,500 a year includes hardware to host service internally. [34] Recommended Use: Distance learning institutions. Sources: http://www.wimba.com/

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Sources List of Tools information: Vsee

http://vsee.com/index.html : http://vsee.stanford.edu/wall/ Skype and Unyte

http://www.skype.com/ : http://www.unyte.net/ Evo

http://evo.caltech.edu/ GroupWorld

http://www.groupworld.net/ Adobe Connect and Connect Pro

http://www.adobe.com/products/connect/ VNC http://www.realvnc.com/ http://www.tightvnc.com/ Gizmo

http://gizmoproject.com/ Microsoft Messenger

http://get.live.com/messenger/overview I-Linc

http://www.ilinc.com/ Microsoft Live Meeting

http://office.microsoft.com/en-us/livemeeting/FX101729061033.aspx WebEx

http://www.webex.com/ Horizon Wimba

http://www.wimba.com/

Appendix III: Research Poster

High Definition VideoconferencingGregg Trueb, Suzanne Lammers, Prasad Calyam

Ohio Supercomputer Center {gtrueb, slammers, pcalyam}@osc.edu

I. High Definition Videoconferencing (HDVC)

Vs. Standard Definition

Videoconferencing (SDVC) - HDVC is a new technology;

traffic characteristics not well understood; packet size distribution, video encoding rates, bandwidth consumption

- HDVC has unique display

requirements; higher resolution, larger screen

II. Collaboration Tools & HDVC

- Collaboration tools are becoming a necessity at the workplace

- Compare collaboration tool

features available today - Assess how they can be

implemented in HDVC in future

VSee

Adobe Connect

Microsoft Live Meeting

Application sharing

Chat

SD

HD

Videoconferencing

Annotation

High Definition Videoconferencing (Contd.)

Acknowledgements: OSC: Nathan Howes, Terry Lewis, Arif Khan, David Kehrle, Pankaj Shah

ADEC: Janet Poley, Janet Means

III. HDVC Security

- Misconfigured Firewall/NAT cause video problems - Solutions: H.323 Fixup in Cisco’s PIX, Polycom

V2IU device, and GNU Gatekeeper - Comparing HDVC performance with the

Firewall/NAT traversal solutions

IV. HDVC Application Domains

- Business Meetings - Health Care - Distance Education - Wild-life Conservation - Judicial Applications

This work has been supported by- • American Distance Education Consortium (ADEC) • NSF Research Experience for Undergraduates (REU) • Ohio Supercomputer Center