Activity 1 Ece 583l

7/30/2019 Activity 1 Ece 583l

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ACTIVITY 1: Standards, Standards Organization and Introduction to the OSI Reference Model LearningObjectives

Upon completion of this experiment, the student shall be able to:

Explain the standardization process Explain the importance of standards in data communication

Enumerate organizations and their contributions in the field of data communication Explain the functions of the different Layers of the OSI Reference Model

Requirements

Internet Access

Background

During the 1970's and 1980's data and computer networking is growing exponentially. Furthermore theincreasing demands for support services have disturbed the stability of the market over the years. For thisreason, a process called standardization is introduced. As a result International, regional, and nationalorganizations have worked together to speak the same language. Standardization enabled the market to bestable by allowing vendors to manufacture equipments compatible with any other equipment including aspecific standard. For example home and business networkers are looking to buy wireless local area network(WLAN) routers and they end up in array of choices like D-link, Linksys, Trendnet, etc and yet all of thoseequipments conform to an IEEE 802.11x standard. Standards have been adopted by most communicationcompanies and carriers to provide quality service worldwide. These are the list of the principal advantages anddisadvantages during the standard- making process:

Advantages:

a. A standard assures that there will be a large market for a particular piece of equipment or software.This encourages mass production and, in some case, the use of large-scale-integration (LSI) or very-large-scale-integration (VLSI) techniques, resulting in lower costs.

b. A standard allows product from multiple vendors to communicate, giving the purchaser more flexibilityin equipment selection and use.

Disadvantages:

a. A standard tends to freeze the technology. By the time a standard is developed, subjected to reviewand compromise, and promulgated, more efficient techniques are possible.

b. There are multiple standards for the same thing. This is not a disadvantage of standards per se, but of the current way things are done. Fortunately, in recent years the various standards-makingorganizations have begun to cooperate more closely. Nevertheless, there are still areas where multipleconflicting standards exist. Data communication standards fall into two categories: de facto (by fact orby convention) and de jure (by law or regulation) De facto : Standards that have not been approved byan organized body but have been adopted as standards through widespread use are de facto standards.Such were established originally by the manufacturers to define the functionality of a new product ortechnology. De jure : Standards that have legislated by an officially recognized body are de jurestandards.

I. Standardization Process: An Example

A step in a Standardization process includes having a recommendation from IETF (Internet Engineering TaskForce) for the advancement of the protocol, and ratification of IAB (Internet Architecture Board). Moreover, astandardization process must be finished at a minimum practical time. A proposed standard must remain for at


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least six months and a draft standard for at least four months for the allotment of time for revisions. Anexperimental comment known as RFC (Request for Comment) is published for protocol/s or specifications thatare not considered ready for standardization. However, it may be resubmitted after further work byimplementation and operational experience with consideration of stability and significance to provideworldwide service, and then a RFC number will be assigned to the proposed standard. On the other hand, whena protocol becomes out of date, it is assigned to the historic state.

Questions:

1.1 Discuss the importance of having a standard.It is important to have a standard to assure that there will be a large market for a particular piece of

equipment or software. This assures mass production, and in some case, the uses of LSI or VLSI techniquesresult in lower costs. One also of its advantage allows product from multiple vendors to communicate, givingthe purchaser more flexibility in equipment selection and use.

1.2 Why can it take up to four years or more for the ITU to adopt a recommendation?The major subdivision of CCITT was into Study Groups identified by roman numerals (Study Group VII isone of the more important for OSI work). (ITU-T has similar divisions, but arabic numerals are now used, soStudy Group VII has become Study Group 7). The Study Groups tend to have a relatively permanentexistence, while lower-level structures ( Rapporteur Groups ) are more transient. It is the Study Group thatforms the basis for most international meetings (almost all at the headquarters of CCITT/ITU-T in Geneva),with all the Rapporteur Groups (and their subdivisions) of the Study Group meeting together over a periodof two to three weeks.

In the past (up to the 1988 Blue Books - the last of the series), CCITT worked to a strict 4-year schedule(in particular, 1976 to 1980, 1980 to 1984, and finally 1984 to 1988). At the start of these four year StudyPeriods a set of Questions would be formulated and agreed by a CCITT plenary meeting. These Questionswere assigned to the Study Groups, and formed the programme of work for each Group in the coming StudyPeriod. Roughly speaking, each Question would give rise to a new or amended Recommendation oncompletion of the four year Study Period. Following the end of the Study Period, the entire set of CCITTRecommendations (whether changed or not) was republished as a set of volumes in bindings whose colourchanged with each Study Period. Thus people spoke of "the Yellow Books" (published after the 1980 plenarywhich approved the 1980 Recommendations), or "the Yellow Book Era" (1980 to 1984), "the Red Books"published after the 1984 plenary, and finally "the Blue Books" published after the 1988 plenary, the last of the set. From 1990 onwards, CCITT/ITU-T will publish Recommendations only when necessary. Completepublication every four years has ceased.


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1.3 What is a RFC (Request for Comment)? ExplainAn experimental comment known as RFC (Request for Comment) is published for protocol/s or

specifications that are not considered ready for standardization. However, it may be resubmitted afterfurther work by implementation and operational experience with consideration of stability and significanceto provide worldwide service, then a RFC number will be assigned to the proposed standard. On the otherhand, when a protocol becomes out of date, it is assigned to the historic state.

II. Standards Organization

Standards are developed through the cooperation of standards creation committees, forums and governmentregulatory agencies. International Organization for Standardization (ISO) the ISO is a multinational body whosemembership is drawn mainly from the standard creation committees of various governments throughout theworld. It is active in developing cooperation in realms of scientific, technological and economic activity.Log on to the homepage of ISO (http://www.iso.org/iso/home.htm). Look at the About ISO section, then click The ISO System.

2.1 As abbreviated, the International Organization for Standardization was given the acronym ISO. How was theacronym derived?

ISO (International Organization for Standardization) is the worlds largest developer of voluntaryInternational Standards. International Standards give state of the art specifications for products, services andgood practice, helping to make industry more efficient and effective. Developed through global consensus, theyhelp to break down barriers to international trade. The ISO story began in 1946 when delegates from 25countries met at the Institute of Civil Engineers in London and decided to create a new internationalorganization to facilitate the international coordination and unification of industrial standards. In February1947 the new organisation, ISO, officially began operations.

Since then, we have published over 19, 000 International Standards covering almost all aspects of technology and manufacturing. Today we have members from 164 countries and 3 335 technical bodies to takecare of standard development. More than 150 people work full time for ISOs Central Secretariat in Geneva,Switzerland. Because 'International Organization for Standardization' would have different acronyms in differentlanguages (IOS in English, OIN in French for Organisation internationale de normalisation ), our founders decided

to give it the short form ISO. ISO is derived from the Greek isos, meaning equal. Whatever the country, whateverthe language, the short form of our name is always ISO.

2.2 How are standards developed by ISO?ISO standards are developed by the people that need them, through a consensus process. Experts from all

over the world develop the standards that are required by their sector. This means they reflect a wealth of international experience and knowledge. An ISO standard is developed by a panel of experts, within a technicalcommittee. Once the need for a standard has been established, these experts meet to discuss and negotiate adraft standard. As soon as a draft has been developed it is shared with ISOs members who are asked tocomment and vote on it. If a consensus is reached the draft becomes an ISO standard, if not it goes back to thetechnical committee for further edits.

2.3 What are the three categories of membership to the ISO? Describe each category. Is the Philippines amember body of the ISO? If so, what governing body represents the Philippines to the ISO?

Full members (or member bodies) influence ISO standards development and strategy by participatingand voting in ISO technical and policy meetings. Full members sell and adopt ISO International Standardsnationally.

Correspondent members observe the development of ISO standards and strategy by attending ISOtechnical and policy meetings as observers. Correspondent members can sell and adopt ISO International Standards nationally.


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Subscriber members keep up to date on ISOs work but cannot participate in it. They do not sell or adopt ISO International Standards nationally.

Philippines is a member body of the ISO. The governing body that represents the Philippines to the ISO is theBureau of Product Standards or (BPS).

2.4 Return to the homepage of the ISO. At the Standards Development Section, click the Technical Committeeslink. Look at the list of the ISO technical committees and complete the table below:

Committee Title Standards PublishedJTC1 Information Technology 2547TC43 Acoustics 196TC48 Laboratory Equipment 110TC69 Applications of Statistical Methods 93

TC172 Optics and Photonics 289TC181 Safety of Toys 5

One of ISOs greatest contribution s in the field of data communications is the Open Systems InterconnectionModel (ISO 7498) since ISO7498 is not a free document, one may learn the highlights of the OSI model throughthe wiki (http://en.wikipedia.org/wiki/OSI_model) . Proceed to the wiki site and answer the following:

2.5 Describe the layering approach as a means of analyzing network architecture.According to recommendation X.200, there are seven layers, labeled 1 to 7, with layer 1 at the bottom.

Each layer is generically known as an N layer. An "N+1 entity" (at layer N+1) requests services from an "N entity"(at layer N). At each level, two entities (N-entity peers) interact by means of the N protocol bytransmitting protocol data units (PDU). A Service Data Unit (SDU) is a specific unit of data that has been passeddown from an OSI layer to a lower layer, and which the lower layer has not yet encapsulated into a protocol dataunit (PDU). An SDU is a set of data that is sent by a user of the services of a given layer, and is transmittedsemantically unchanged to a peer services user. The PDU at a layer N is the SDU of layer N-1. In effect the SDU isthe 'payload' of a given PDU. That is, the process of changing an SDU to a PDU, consists of an encapsulationprocess, performed by the lower layer. All the data contained in the SDU becomes encapsulated within the PDU.The layer N-1 adds headers or footers, or both, to the SDU, transforming it into a PDU of layer N. The addedheaders or footers are part of the process used to make it possible to get data from a source to a destination.2.6 In order, what are the layers of the OSI model?

OSI ModelData Unit Layer Function

Hostlayers

Data7.Application Network process to application

6.Presentation Data representation, encryption and decryption, convert machine dependentdata to machine independent data

5.Session Interhost communication, managing sessions between applicationSegments 4.Transport End to end connections, reliability and flow control

Medialayers

Packet/Datagram 3.Network Path determination and logical addressing

Frame 2.Data Link Physical addressing

Bit 1.Physical Media, signal and binary transmission
http://en.wikipedia.org/wiki/Protocol_data_unithttp://en.wikipedia.org/wiki/Protocol_data_unithttp://en.wikipedia.org/wiki/Protocol_data_unithttp://en.wikipedia.org/wiki/Service_Data_Unithttp://en.wikipedia.org/wiki/Service_Data_Unithttp://en.wikipedia.org/wiki/Service_Data_Unithttp://en.wikipedia.org/wiki/Service_Data_Unithttp://en.wikipedia.org/wiki/Protocol_data_unit


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2.7 Associate the following services/processes/protocols to their corresponding OSI layer:

Services/Processes/Protocols OSI LayerPackets PhysicalModulation PresentationPhysical Addressing Data LinkLogical Addressing Network

Transmission Control Protocol (TCP) TransportDialog Control SessionInternet Protocol ApplicationFrame Data LinkHTTP Application

International Telecommunications Union the ITU is the leading United Nations agency for information andcommunication technology issues, and the global focal point for governments and the private sector indeveloping networks and services. To know more of the ITU, log-on to the ITU site(http://www.itu.int/net/about/) . Briefly answer the following.

2.8 What are the three sectors of the ITU and describe the functions of each sector.ITU has three main areas of activity organized in Sectors which work through conferences and meetings:

RadiocommunicationITU's Radiocommunication Sector (ITU-R) coordinates this vast and growing rangeofradiocommunication services, as well as the international management of the radio-frequencyspectrum and satellite orbits. An increasing number of players need to make use of these limitedresources, and participating in ITU-R conferences and study group activities where important work isdone on mobile broadband communications and broadcasting technologies such as Ultra HDTV and 3DTV is becoming an ever-higher priority for both governments and industry players.

StandardizationITU standards (called Recommendations) are fundamental to the operation of todays ICT networks.Without ITU standards you couldnt make a telephone call or surf the Internet. ForInternetaccess, transport protocols, voice and video compression, home networking, and myriad other aspectsof ICTs, hundreds of ITU standards allow systems to work locally and globally.

DevelopmentITU's Telecommunication Development Sector (ITU-D) has a programme to offer you whether you areinterested in entering or expanding your presence in emerging markets, demonstrating global ICTleadership, learning how to put goodpolicy into practice, or pursuing your mandate for corporate socialresponsibility.

ITU-T Recommendations are defining elements in information and communication technology (ICT)infrastructure. Whether we exchange voice, data or video messages, communications cannot take place withoutstandards linking the sender and the receiver. In data communications, the most notable recommendationsinclude the V, X, I, G, H and the Q-series recommendations. View the recommendation page(http://www.itu.int/ITUT/publications/recs.html) to complete the table below:
http://www.itu.int/itu-rhttp://www.itu.int/itu-dhttp://www.itu.int/itu-dhttp://www.itu.int/itu-r


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ITU-T Recommendation DescriptionV-series Data communication over the telephone network

X-series Data networks, open system communications and security

I-series Integrated services digital network G-series Transmission systems and media, digital systems and networks H-series Audiovisual and multimedia systems

Q-series Switching and signalling

To get an insight of some of the ITU-T recommendations mostly used in data communications, see the ITU-Trecommendations page (http://www.itu.int/itu-t/recommendations/index.aspx) . Complete the table belowwith the following recommendations:

ITU-T Recommendation DescriptionG.711 (PCM) Pulse code modulation of voice frequencies (11/1988)V.24 List of definitions for interchange circuits between data terminal

equipment (DTE) and data circuit-terminating equipment (DCE)(02/2000)

X.200 Information technology Open Systems Interconnection BasicReference Model: The basic model (07/1994)H.323 Packet-Based multimedia communications systems (12/2009)

2.9 Comparatively, the OSI model can be compared to what ITU-T standard?

OSI model describes from the ITU-T as the X.200 series of recommendations.

Institute of Electrical and Electronics Engineers (IEEE) By far, the IEEE is considered as the largest professionalorganization for electrical, electronics, and computing engineers. Notably, IEEE is highly acclaimed in the datacommunications industry because of their efforts in the development of the IEEE802 standards. To get anoverview of the IEEE802 standards, please view their portfolio on this web linkhttp://standards.ieee.org/getieee802/portfolio.html Answer the following questions:

2.10 Identify the following names of the following IEEE802 active working groups:

Group TitleIEEE802.3 ETHERNETIEEE802.5 TOKEN RINGIEEE802.11 WIRELESS LANs(Local Area Networks)IEEE802.15 WIRELESSPANs ( Personal Area Networks)

2.11 Click the link of the IEEE802 Working groups. What are the two inactive working groups?

The Two Hibernating Working Groups and Study Groups

802.17 Resilient Packet Ring Working Group 802.20 Mobile Broadband Wireless Access (MBWA) Working Group
http://standards.ieee.org/getieee802/portfolio.htmlhttp://standards.ieee.org/getieee802/portfolio.htmlhttp://standards.ieee.org/getieee802/portfolio.html


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Electronic Industries Alliance (EIA) is a non-profit trade organization composed as an alliance of tradeassociations for electronics manufacturers in the United States. EIA is accredited by ANSI to help developstandards on electronic components, consumer electronics, electronic information, telecommunications, andInternet security. The recommended standards (formerly designated as RS-#, currently EIA-#) are designed sothat manufacturers equipment can be interchanged and compatible. Some of the well -knownrecommendations made by the EIA include the EIA-232, EIA-449 and EIA-530. To have a glimpse of the EIA-232,proceed to the wiki site as provided (http://en.wikipedia.org/wiki/RS-232) . Answer the following questions:

2.11 What four specifications does the EIA-232C of 1969 define?The Electronic Industries Association (EIA) standard RS-232-C as of 1969 defines:

Electrical signal characteristics such as voltage levels, signalling rate, timing and slew-rate of signals,voltage withstand level; short-circuit behaviour, and maximum load capacitance.

Interface mechanical characteristics, pluggable connectors and pin identification. Functions of each circuit in the interface connector. Standard subsets of interface circuits for selected telecom applications.

Proceed to the Connectors Section to answer this question.

2.12 RS-232 devices may be classified as Data Terminal Equipment (DTE) or Data Circuit-terminating Equipment(DCE). What type of connector should be used for devices with DTE pin functions? With DCE pin functions? Inthe RS-232 specification, the pin connector is composed of how many pins?

RS-232 devices may be classified as Data Terminal Equipment (DTE) or Data Communication Equipment(DCE); this defines at each device which wires will be sending and receiving each signal. The standardrecommended but did not make mandatory the D-subminiature 25 pin connector . In general and according tothe standard, terminals and computers have male connectors with DTE pin functions, and modems have femaleconnectors with DCE pin functions. Other devices may have any combination of connector gender and pindefinitions. Many terminals were manufactured with female terminals but were sold with a cable with maleconnectors at each end; the terminal with its cable satisfied the recommendations in the standard. The standard

specifies 20 different signal connections. Since most devices use only a few signals, smaller connectors can oftenbe used.

For PC technology leading manufacturers started early to replace the once common DB-25M connector by themore compact and thus somewhat cheaper DE-9M connector for their devices. As the pin assignments neededto be condensed a noticeably different pin order was selected for that mechanical variant (for this see serialport) . This type of connector became the de-facto standard for PCs and as well for many other DTE devices.

Internet Society (ISOC) Internet standards are developed by group of organizations which operate under theauspices of the Internet Society (ISOC). Log-on to the standards section of the ISOC(http://www.isoc.org/standards/) and answer this question.

2.13 What are the three key areas of the standards and technology priorities of the ISOC?The Three Key Areas of the Standards and Technology of the Internet SOCiety (ISOC) The Internet Engineering Task Force (IETF) is an organized activity of the Internet Society (ISOC), The Internet Research Task Force (IRTF) focuses on longer term research issues related to the Internet

while the parallel organization, and The Internet Architecture Board (IAB) is a committee of IETF. It exists to serve and help the IETF,

attempting to strike a balance between action and reaction.
http://en.wikipedia.org/wiki/D-subminiaturehttp://en.wikipedia.org/wiki/D-subminiaturehttp://en.wikipedia.org/wiki/Serial_port#Pinoutshttp://en.wikipedia.org/wiki/Serial_port#Pinoutshttp://irtf.org/http://irtf.org/http://en.wikipedia.org/wiki/Serial_port#Pinoutshttp://en.wikipedia.org/wiki/Serial_port#Pinoutshttp://en.wikipedia.org/wiki/D-subminiature


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Internet Engineering Task Force (IETF) The IETF is a large, open international community of network designers,operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smoothoperation of the Internet. It is open to any interested individual. The IETF's technical work is performed byworking groups, organized into major topic areas.

The IETF's official products are documents, published free of charge as Request for Comments (RFC). The IETF isas the group of people who work together to improve the technology of the Internet on a daily basis. As well as

producing RFCs, the IETF is a forum where network operators, hardware and software implementers, andresearchers talk to each other to ensure that future protocols, standards and products will be even better.

To have an overview of RFC, log on to IETFs RFC page (http://www.ietf.org/rfc.html) . On the IETF RepositoryRetrieval, type 1918, then click Go. Browse the document to answer the following questions:

2.14 What does RFC 1918 describe?

RFC 1918 or Address Allocation for Private Internets: The allocation permits full network layer connectivityamong all hosts inside an enterprise as well as among all public hosts of different enterprises. The cost of usingprivate internet address space is the potentially costly effort to renumber hosts and networks between publicand private.

2.15 How do you differentiate hosts that require private from public IP addresses?Hosts within enterprises that use IP can be partitioned into three categories:Category 1: hosts that do not require access to hosts in other enterprises or the Internet at large; hosts

within this category may use IP addresses that are unambiguous within an enterprise, but may be ambiguousbetween enterprises.

Category 2: hosts that need access to a limited set of outside services (e.g., E-mail, FTP, netnews,remote login) which can be handled by mediating gateways (e.g., application layer gateways). For manyhosts in this category an unrestricted external access (provide via IP connectivity) may be unnecessary andeven undesirable for privacy/security reasons. Just like hosts within the first category, such hosts may us IPaddresses that are unambiguous within an enterprise, but may be ambiguous between enterprises.

Category 3: hosts that need network layer access outside the enterprise (provided via IP connectivity);hosts in the last category require IP addresses that are globally unambiguous.Hosts in the first and second categories refer as "private", and the hosts in the third category as "public".

2.16 According to RFC1918, what are the three blocks of IP private addresses space reserved by the InternetAssigned Numbers Authority (IANA) for private internets?

The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP addressspace for private internets:

10.0.0.0 - 10.255.255.255 (10/8 prefix) 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)

192.168.0.0 - 192.168.255.255 (192.168/16 prefix)


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Activity 1 Ece 583l