EtherScope™ Series II Network Assistant Next generation network analyzer helps first responders solve problems fast ECA02132007

EtherScope™ Series IINetwork Assistant

Next generation network analyzer helps first responders

solve problems fast

ECA02132007

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Outline

• Introduction to EtherScope LAN• Introduction to EtherScope WLAN• Additional EtherScope WLAN Features• RFC 2544 Testing

– (Throughput, Latency, and Frame Loss Rate)

Introduction to EtherScope LAN

LAN analysis and performance testing

10/100/1000Mbps RJ-45 twisted pair interface

1000Mbps LC fiber optic interface

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Components

Specifications:• OS: Embedded LinuxTM (X-scale based)

• Touch Screen: 640x480 TFT (Active)

• Custom network testing hardware

• 256Mb RAM, 32Mb ROM

• 64 Mb Compact Flash Card Included (for saved test results/reports)

•Expandable

• Weight: .82 kilograms or 2 pounds

• Dimensions: 19.1 x 15.2 x 4.4 centimeters or 7.5 x 6 x 1.75 inches

Serial Port (can be used to configure network devices)

Audio Ports (MIC, Headphone)

USB (optional mini-keyboard, mouse)

Power

Stylus

SFP Fiber Transceiver

LAN Test Port

WLAN Card (PCMCIA)Compact Flash (CF2)

Kensington Lock

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Power On/Off•Two modes:

Shut Down or Suspend

Protective Rubberized “Boot”

Bright Active Matrix Touch Screen

Battery:•Lithium-Ion Rechargeable•Approx. 4 hours use / charge•Optional extra battery and charger stand

Status LEDs•Link•Utilization•Collisions•Errors•Transmit

Components

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Home Page: Test Results and Navigation

Blue text indicates hyperlinks to more detail

“Menu”-based navigation with highlights of selected test shown at left

“Details” drills in on selected test for more results

Tool Bar – a convenient and consistent navigation and information platform.

Easy navigation:• Back• Home• Tools• Help

Touch icon for instant link to specific tests

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Instrument Settings

Drill in on Connection to reach Instrument Settings, where you can configure TCP/IP, Ethernet, Security, and General instrument settings. Add community strings and security passwords, change Ethernet negotiation characteristics and interfaces.

Get an IP Address via

DHCP, or manually -

DHCP Server Log appears after hitting

“Apply”

Password to control

community string and Remote U/I

access

Note the default

community strings

Save time with ‘Fast Connect Mode’ • Check for Link• Check Address• Go to next drop

Add management VLAN devices here

Full control of your

connection settings

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Cable Verification

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Cable Verification Details

Launches on-board ANALOGToner

Changes the color code order in wiremap results

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IntelliTone Toner

• Generate analog or IntelliTone tones to help locate copper cabling– choice of two tones

• Click Cable Verification, Details and Cable Toner

choice of modes

and tones

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Fiber test kit (DSP-FTK) support• Measure the optical power or the loss of an optical fiber link using the

DSP-FTK fiber test kit– DSP-FTK = DSP-FOM and FOS-850/1300

• Click Cable Verification, Details, then select the Fiber button• Connect DSP-FOM to LAN port

power, loss and margin set reference for loss

measurement

auto wavelength detection

(FOM)

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Signal Verification Scans for DC voltage levels andover voltage conditions. Perfect for trouble-shooting Power Over Ethernet!

Checks for presence and amplitude of link pulse and data signals

Supported signaling and link partner-EtherScope advertised auto-negotiation

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Traditional switched network

Switch

Switch

SwitchSwitchRouter Floor 1

Floor 2

Floor 3

Broadcast domain

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Switched network with VLANs

Switch

Switch

SwitchLayer 3 Switch or Router

Router Floor 1

Floor 2

Floor 3

Broadcast domain

Engineering VLAN

Accounting VLAN

Sales VLAN

Either dedicated cables or a VLAN “trunk”. A trunk link can carry traffic from multiple VLANs.

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EtherScope network visibility boundaries

From a single connection, EtherScope can see the • Collision Domain - local statistics• Broadcast Domain – device, network, VLAN discovery

Collision domain statistics

Broadcast domain discovery (SNMP)

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EtherScope local VLAN statistics

• If the ES is connected to a trunk port, multiple VLANs will be present

• Use “VLAN Statistics” to identify the VLANs that are active on the port (includes the Native or untagged VLAN traffic)

• If you select a VLAN ID that is unconfigured on the port to which the EtherScope is connected, it might not be able to communicate with the network (e.g. DHCP fails)– Try configuring the ES for the VLAN with

the highest packet count

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EtherScope VLAN discovery

• The number of VLANs reported by VLAN Statistics and VLAN Discovery will frequently differ

• VLAN Statistics shows VLANs detected by monitoring the local network segment while VLAN Discovery is using active (SNMP) discovery

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IEEE 802.1Q

• Standard methodology for constructing a VLAN trunk• A “VLAN tag” is added to the Ethernet frame by the switch

that is trunking traffic to identify the VLAN• The last trunk switch will strip off the tag before forwarding

the frame to the destination

VLAN tag(includes CoS)

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EtherScope on a trunk port• Tap “Enable 802.1Q” checkbox to turn on VLAN tagging• Use the “VLAN ID” field to designate the VLAN number that

the ES will use• Use the “Priority” field to set the user priority (CoS) for the

frames generated by the ES

• Active discovery will be limited to the devices on the selected VLAN (broadcast domain)

• Can only enable 802.1Q if the port of the link partner has .1Q enabled

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Class of service (CoS) priority

• CoS provides a means of prioritizing which traffic the switch will process first– Example: give VoIP traffic higher priority than web traffic– 802.1p is an subset of 802.1Q VLAN tagging

• Layer 2 intranetwork priority mechanism (switches and MAC addresses)

• 802.1Q and 802.1p CoS support added to EtherScope to facilitate observation of layer 2 CoS priority on link performance– User can configure the priority of

the traffic EtherScope generates

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Type of Service priority• Like CoS, provides a means of prioritizing traffic

– Layer 3 internetwork traffic (routers and IP addresses)– Examples: VoIP traffic over web traffic , critical application traffic

over email

• Two versions– TOS with IP precedence

• 4 attributes (delay, throughput, reliability, cost)

– TOS with differentiated services code point (DSCP)• 8 attributes for more flexible control

• Support added for IP type of service (TOS)

Dest MAC

Source MAC

Source IP

Dest IP Data FCSType0800

Layer 2 Addressing Layer 3 Addressing

TOS Byte of IP header

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Local Statistics

Notice the detailed preview information – giving you a quick look so you can decide at a glance whether you want to drill-in further… Something looks suspicious here, don’t you think? –

Just click on ‘Details’

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Local Statistics, Details

Note that you can also change the source, and the interface to trend a remote device as well. This helps you follow the scent of problems and enables you to track them down and fix them quickly!

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Local Statistics, Details

So you click on the Details button or on the Local Utilization link to see what’s happening.

Note that you can also change type of information displayed. Here you see Error Details. Oversize and Undersize frames

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Remote Statistics, DetailsChoose a different source (switches only!) and interface to monitor

On selected device and interface,

EtherScope reads only the

Layer 2 interfaces.

It Pulls MIB II information, but

no RMON history, so single port statistics are

shown

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Top Protocols

Notice the summary protocol statistics, listed in BLUE – that means they are ‘clickable’ to drill in for additional details

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Protocol Statistics Detail

Top sources of the selected packet type are listed in order.

Throughout EtherScope’s User Interface, data can be sorted by headings, and selected by type

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Top Talkers At the top level, see top talkers at a glance. Drill in to see details of this particular bandwidth hog

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Top Talker DetailDetailed information available on top talkers. Select a particular talker and tap the ‘Details’ button to obtain still another level of drill-in.

Select the radio buttons to list senders of Errors, Broadcasts and Multicast traffic

Note that where appropriate, applicable buttons will appear, in-context… Here you can ‘Clear’ the packet counts, or generate and store a ‘Report’

Click to see Layers of protocols available

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Top Talker IPV4 Protocol Detail

Detailed information available on the distribution of IPV4 Protocol

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Device Discovery Summary level information about the devices discovered. Again, you can drill in to see a list of all devices, or a particular type of device you are interested in, just by selecting it

Note that while the green ‘check-mark’ indicates that EtherScope has completed its first pass on Device Discovery - it continues to listen to traffic to identify and report on new network devices it discovers.

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Device Discovery, Details Drilled-in on All Devices, see the Name, IP Address, Switch Slot/Port, VLAN, and any associated problems

Use these radio buttons or use the scroll-bar to navigate through the table to see additional details on the devices.

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Device Discovery Report

A sample report listing pertinent information on all devices.

Column headings can be sorted here as well.

Document the network!

Reports saved to Compact Flash, accessible via Web interface

MUST have CF installed to save reports!

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Device Details by Type - Switches

Overview of device configuration information is shown here

Individual Device Traffic shown here. Select a device and tap the ‘Details’ button to again to obtain still another level of drill-in.

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Specific Device Details

Device-specific links and appropriate troubleshooting tools are now available.

Note that you can drill in on the switch interfaces to see who’s connected on each port

Quick launch troubleshooting tools

Detailed information about this particular switch is shown in the main screen

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Switch Interface DetailsHere we have drilled-in on the switch Interface Detail link which shows the status and configuration of all the ports, including who’s connected to each!

You can even select one of the hosts and drill in further on it…

Notice the problem icon showing Host EVTPC1272… time for some investigation. You can sort on that column to see all the problems discovered on this switch port…

Problem discovery speeds troubleshooting.

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Trace Switch RouteTrace Switch Route shows you the Layer 2 connection path between EtherScope and the selected device.

The “from” device is always the EtherScope. The “destination” is selected in the drop down box.

Want to see the interface details or monitor utilization on the connecting switch port? Just drill in on the BLUE highlighted Slot/Port to go there.

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Network Discovery Overview

EtherScope lists all the networks discovered, and provides quick information about the number of hosts on each

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Network Discovery Details

Select and expand the IP Subnets to see detailed information on how the network is organized, and which hosts are members

By now, you recognize that you can select and drill-in on any subnet or device to get additional details…

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VLAN Discovery

See VLANs, and associated switch ports and hosts.

Trunks are not shown.

Discovery of all VLANs within connected broadcast domain only (discovered switches).

Finds by way of reading switch configs

Lists hosts by VLAN

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Nearest Switch

EtherScope locates the nearest switch and monitors it for you

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Switch Scan

Monitoring these switches for high utilization and errors.

Automatically shows nearest switch and one other user-selected switch.

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Switch Scan Details

See the Average and Peak Utilization on all the active ports of two selected switches.

Visibility of traffic IN and OUT.

Average and Peak reading results shown since Switch Scan was activated.

Select another switch to monitor from the drop-down list

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Switch Scan Trending

Select a port from the previous then click Trend for Utilization History

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Key Devices

EtherScope automatically checks on selected Key Devices when it starts up, and again whenever you select ‘Start Test’

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Problem Log Details

EtherScope monitors network conditions and automatically alerts you to detected problems.

Errors, Warnings, and Info Messages are listed. Intermittent Problems are reported and listed as Resolved, so even if they go away you know about them

You can delete selected or resolved problems (or ‘undo’ if deleted by accident)

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Documenting the LAN• Save results as a Report to document wired LAN attributes

– click on Report button found on most Detail screens

• Use Report Viewer and File Manager applications to view and manage reports on-board

open to view

open, rename or

delete

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Remote Access Via Web Browser

Access real time or saved reports

Launch a remote session; can require password – default is blank (nothing)

Direct link to support resources at www.flukenetworks.com

Access the embedded Online Help file

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Performance testing

• How do you know that a newly installed network link or network device is really delivering the performance he expects?

• Is the performance sufficient for successful data transfers, email, web-based seminars, VoIP and other applications?

• Are user complaints of a slow network true?• How will adding additional users to a segment of your

network impact network performance?• The RFC 2544/ITO Option helps answer these questions.

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RFC 2544/ITO Option

• This option includes– RFC 2544 performance testing– a traffic generator– the proprietary Throughput Test found on other Fluke Networks

analyzers like the OneTouch Network Assistant and the OptiView Integrated Network Analyzer

• Select the RFC 2544 tests to characterize the performance of a network link using the well-accepted IETF recommendation

• Select the proprietary Throughput Test for quick verification that a link can carry a specific, user-defined data rate for a set interval of time

• Test at up to full line Gigabit rates• Over twisted pair or optical fiber (SX, LX, ZX) cabling

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RFC 2544 Tests• Characterize network performance by

selecting one or more of the three most valuable RFC 2544 performance metrics– throughput– latency– frame loss rate

• For each test, you can use the default frame and test defaults, or customize the configuration– When testing a trunk port for example,

you can identify a VLAN ID, turn on 802.1Q VLAN tagging and override the default 802.1Q priority setting

– You can override the Type of Service (TOS) IP Precedence and DSCP parameter

– You can also control the time it takes to complete a test by adjusting the accuracy and failure thresholds.

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Maximize efficiency and timesavings

• Select multiple target devices for each RFC 2544 test to maximize testing efficiency and timesavings– Add the same target device, with

differing test configurations, multiple times to the same test to see how traffic differences affect link performance

– Add different target devices to the same test to measure multiple links within your network

– Devices and configurations can vary by test

– Once you construct your test suite, click the Start button once to commence testing to all device Main Remote

Network

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Save, print, email or store test results

• Tests run in both upstream and downstream directions, saving time by eliminating the need to physically swap source and target devices

• You can view the results by device and by test

• See test results in table view or graph view mode

• Save, print, email and store the results to document link performance.

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ITO Traffic Generator• Use a single EtherScope to generate traffic up to full line rate at

10/100/1000 Mbps speeds• Simulate the addition of new users on a segment by generating

broadcast, multicast or unicast traffic• Select the frame type and size and the test duration.

can also access from

Tools

Introduction to EtherScope WLAN

802.11a/b/g wireless LAN analysis

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What are the problems with wireless networks• Don’t know what network types are active

– feature: Network Discovery

• Don’t know who is using the WLAN• Need to verify device configurations• Can’t connect or login• Not getting the expected performance (“too slow”)• Security concerns (e.g. rogue clients)• WLAN isn’t documented

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Discovering the types of wireless networks

• click “Network Discovery”• Four network types are discovered

– an infrastructure network is comprised of systems and mobile clients connected through an Access Point (AP) which is connected to wired Ethernet network. Most common type.

– an adhoc network is comprised of mobile clients transmitting directly to any other; No AP needed

– a bridge network is comprised of two APs or dedicated 802.11 bridges that communicate to provide link between two physically separate networks

– a IP subnet is comprised of WLAN devices for which IP addresses have been discovered including EtherScopes

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Network discovery

• Click Details to see the wireless network hierarchy discovered by EtherScope at its present physical location

insert screen shot of Network

Discovery details

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• Don’t know who is using the WLAN– feature: Device Discovery

• Need to verify device configurations• Can’t connect or login• Not getting the expected performance (“too slow”)• Security concerns (e.g. rogue clients)• WLAN isn’t documented

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Discovering who is using the network

• Click “Device Discovery” then “Details”• see the number of devices on the network by type• an access point is the “connecting” point used to coordinate wireless

traffic and provide connectivity to the LAN. • a bridge node is a device that provide a wireless connection between

wired networks. This feature can be built into Access Points.• a mobile client is an end point or node on the wireless network. These

are typically general purpose computers but might also include other dedicated wireless devices.

• an adhoc client is a node that comprises a peer-to-peer network that requires no access point.

• a host is a special category that only includes This EtherScope.

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Device discovery

• Click Details to see a comprehensive list and summary device information

insert screen shot of Device

Discovery details

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• Don’t know who is using the WLAN– feature: Device Discovery

• Need to verify device configurations– feature: Device Discovery Details

• Not getting the expected performance (“too slow”)• Security concerns (e.g. rogue clients)• Can’t connect or login• WLAN isn’t documented

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Configuration information presented• SSID is Service Set ID. Typically, the wireless network comprised of an

AP and wireless stations is given an SSID name. This uniquely identifies a WLAN and is used when configuring security options.

• MAC is a medium access control address. 802.11 devices have unique MAC addresses that are used to identify devices.

• Channel is a common frequency used to direct communication between an 802.11 radio card and an access point.

• Signal is the transmission of 802.11 frames by radiating RF energy at a given strength. The stronger the signal the better the coverage and connection.

• Noise is unwanted, interfering RF energy that disrupt normal system operations. Noise level impacts connectivity and performance.

• Security represents the level of 802.11 packet encryption and network authentication for which a device is configured.

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See traffic summary information by device

• Select a device– packets are units by which

802.11 traffic is transported. – broadcasts are packets sent

to all station on a network (SSID).

– (packet) retries are sent when a receiving station fails to acknowledge a packet

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See device detail overview

• Highlight a device and click Details• See detailed configuration information and options for

additional troubleshooting tools and tests

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– feature: Network Discovery• Don’t know who is using the WLAN

– feature: Device Discovery• Need to verify device configurations

– feature: Device Discovery Details• Not getting the expected performance (“too slow”)

– feature: Channel statistics• Security concerns (e.g. rogue clients)• Can’t connect or login• WLAN isn’t documented

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Troubleshooting wireless LAN performance and connectivity issues

• A common measure of wireless network performance is speed, typically expressed in Mbps

• Speed is impacted by the transmission technology and local RF conditions

• Enterprise WLAN technologies:– 802.11b networks operate in the 2.4 GHz Industrial, Scientific and

Medical (ISM) band of the RF spectrum, sub-divided into 14 channels 22 MHz wide, with indoor range of ~300 feet and max throughput of 11mbps.

– 802.11g networks operate in the 2.4 GHz band of the RF spectrum, sub-divided into 14 channels 22MHz wide, with indoor range of ~300 feet, and max throughput of 54mbps.

– 802.11a networks operating in the 5 GHz band of the RF spectrum (less contention than the 2.4 GHz band), is sub-divided into 12 non-overlapping channels 20 MHz wide, with indoor range of 60-80 feet, and max throughput of 54mpbs.

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Analyze performance and connectivity issues by examining channel statistics• A channel is defined as the common frequency that is used

to direct communication between an 802.11 radio card and an access point. – 802.11b/g

• 14 channels; 11 in US • Channels 1, 6, and 11 non-overlapping• Uses 22MHz wide channels

– 802.11a • 30 channels• Uses 20MHz wide channels• NO overlapping channels

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Channels• Start wireless LAN performance analysis by looking at channel

usage• Click on Channels – Details then select the “Total Utilization %”

channel metric

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Channels

• Next look at coverage– indication of signal quality

• Click on Channels – Details then select the “Signal vs Noise dBm” metric

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Noise

• Non 802.11 energy (non-compliant signal strength)• Get noise readings from radio card • Indicates noise floor level • Used to evaluate channel quality

– Signal-to-Noise ratio

• Noise level impacts connectivity and performance • Shows distribution of noise across channels • Channel Quality represented by signal-to-noise ratio (rule

of thumb?)

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Channels

• Next look at ability to successfully transmit packets• Click on Channels – Details then select the “Retry %” channel metric

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Channels

• If you want to drill deeper on a specific channel, click on channel of interest then Details– focused on a channel, get

more accurate information• Same channel metrics as

available via pull down box

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Channels

• If you want to know more about the devices on a channel, click on channel of interest then Devices

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Analyze wireless network health by examining channel utilization• A channel utilization measures the % of bandwidth

consumed by packets transmitted by wireless devices (Access Points, mobile clients, etc.) on a single frequency

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Channel utilization

• Click on Channels Utilization then Details for utilization by frame (traffic) type and protocol

• Protocols– data is a frame that is used to send data;

contains the payload.– management is a frame used to enable stations

to establish and maintain communications.

– control is a frame that assist in the delivery of data frames between stations.

– retries are typically sent when a receiving station fails to acknowledge a packet.

– FCS errors are indications that corrupted packets have been received.

– Crosstalk is an indication that packets sent on one channel have been received on another channel due to channel overlap.

• Frame types– unicast is a packet for transporting information

directly from one point (node) to another.– multicast is a packet that contains a group

address that delivers the same packet to more than one destination.

– broadcast is a packet where the destination address refers to all nodes on the network.

– retries are typically sent when a receiving station fails to acknowledge a packet.

– FCS errors are indications that corrupted packets have been received.

– Crosstalk is an indication that packets sent on one channel have been received on another channel due to channel overlap.

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Channel utilization• The distribution of frames and protocols is useful to

understand network health• Click Packet Rates on Channel Utilization, Details

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– feature: Channel statistics• Security concerns (e.g. rogue clients)

– feature: Security Scan• Can’t connect or login• WLAN isn’t documented

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Identifying security vulnerabilities

• Security threats are identified two ways– unprotected devices are not using encryption to manage

connections• unprotected devices can be a path into your network

– unauthorized devices are not approved by the IT manager to be on the network

• EtherScope assumes all devices are unauthorized until made otherwise

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Unprotected devices

• Click Security Scan and the Unprotected hyperlink

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Locating unprotected devices

• Highlight the device of interest then click Details• Click the Locate hyperlink

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Locating methods

• Convergence method– Use common omni-directional antenna

– Divide search area into quadrants

– Measure signal strength in each corner

– Move to corner with highest power

– Repeat until found

• Vector method– Use uni-directional antenna

– Divide search area into quadrants

– From center, measure signal strength every 90°

– Move to quadrant with highest power

– Repeat until found

1 2

3, 74

5

8

12 11

6, 109

1

3

2

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Unauthorized devices• Click Security Scan and the Unauthorized hyperlink

– same Location feature to find devices

insert screen shot of security scan

unauthorized devices

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Authorizing devices

• Click Instrument Settings – Authorization to change the current level of authorization– select devices individually or by level

– change to authorized, unauthorized or neighbor• remember to Apply!

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– feature: Security Scan• Can’t connect or login

– feature: Login Diagnosis• WLAN isn’t documented

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Diagnosing client login problems

• If a client is unable to login, you can observe the login process to see where the process fails– Click Device Discovery, Details, Mobile Clients then highlight the

client (with ES physically near)– Click Details, Login Diagnosis and Start– Attempt a client login

Insert screen shot and emphasize key points

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– feature: Security Scan• Can’t connect or login

– feature: Login Diagnosis• WLAN isn’t documented

– feature: Reports

Additional EtherScope WLAN Features

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Other wireless LAN features

• Problem log• Survey site changes• Monitoring key devices• Top talkers• Using network maintenance tools• Configuring your EtherScope

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Detecting problems

• EtherScope automatically identifies potential problems and lists them by severity

• Problem identification is threshold-based

– click Wireless Instrument Settings – Wireless Problems

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Survey site changes

• Select a location from which to periodically survey the WLAN

– click Site Survey, Details, edit Location then Save

– survey data includes APs, channels, error and retry rates, utilization, signal and noise measurements

• Go back to that location at a future date and recall the Previous Survey

– Differences will be highlighted in red

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Monitoring key devices• Select any discovered device with an IP address• Click Key Devices, Details, then select device(s) from the pull down menu

insert screen shot of key devices,

details

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Learn who is hogging network bandwidth

• Click on Channels Top Talkers – Details

• Isolate where the problem is by filtering on channel, network

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What’s a network manager to do?

• What does a network manager do if EtherScope uncovers a performance or connectivity problem?– minimize congestion and/or interference by load-balancing

channels• APs and clients

– improve coverage by adding APs

– alter the RF environment• remove interferers• re-position APs, office equipment, walls

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Network maintenance tools• EtherScope contains many tools to help in configuring and

maintaining the WLAN

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Tools – Connectivity Testing• Ping

– Easy method for verifying IP-level connectivity between EtherScope and another device

– Sends packets to a device to see if it sends a return or an 'echo.' If all the packets 'timeout' the device may be disconnected from the network or at least unreachable

– Launched from within EtherScope application; results displayed on EtherScope Console

– Can run multiple sessions• Trace Route

– Used to determine the IP path a packet uses to reach a device. It shows the number of hops and the IP addresses of devices along the path to a destination host

– Launched from within EtherScope application; results displayed on EtherScope Console

– Can run multiple sessions

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Tools – Infrastructure Configuration • Web browser

– Uses Konqueror as the browser; more limited than multi-purpose Internet Explorer or NetScape

– Used to remotely access an infrastructure device web interface for checking and changing configuration

– Used to access web sites for knowledge base information• Telnet/Secure Telnet

– Used to remotely access an infrastructure device command line interface for checking and changing configuration

– Opens a telnet session – Secure Telnet offers more security before access a device console via an

additional login • Terminal

– Allows EtherScope to be used as an ASCII terminal (terminal emulation) – Connect to infrastructure device and EtherScope via a serial cable; opens a

terminal window – Used to initially configure a switch (e.g., set IP settings, passwords, enable SNMP)

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Tools – Infrastructure maintenance

• FTP/TFTP – File Transfer Protocol (FTP) is a common means used to move

files between devices – Used to transfer configuration and user files to and from

EtherScope– Trivial File Transfer Protocol is a simple version of FTP used by

most infrastructure venders to “put” configuration files and new operating system version onto switches and routers

– Files can be “put” on EtherScope and then used to update a switch or router configuration or version of code

– User configuration files can be stored on a compact flash card

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Configurations (Wireless Instrument Settings)

• TCP/IP Connection Log provides an unique view into the WLAN connection process.

insert screen shot of connection log

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Configurations (Wireless Instrument Settings)• Wireless Security is where

you set the SSID that EtherScope will use to establish link

• Depending upon the security authentication type you may have to enter additional keys, user names, passwords or certificates

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Configurations (Wireless Instrument Settings)• Click Radio to set the Country,

Active Bands, Transmit Settings and Signal measurement units

• You can also apply signal strength corrections– using corrections you can

have the EtherScope WLAN card emulate the RF characteristics of other WLAN cards

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Tools for network maintenance

Only available in LAN mode• Trace Switch Route• Traffic Generator• SSH Telnet• CDP Port Reporter

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Tools

• Trace Switch Route (TSR) – Used for troubleshooting connectivity – Determines the MAC data path between

EtherScope and another device including the starting and ending device and any switches along the path

– SNMP community strings must be configured for TSR use

– Switches must be discovered (or user added) for TSR to work properly

• Traffic Generator– Optional application that is used to generate

synthetic traffic– Used to test the performance of a network by

creating various network loads (high utilization, simulate large number of users)

– Can enable a password to protect the inexperienced user from creating serious network problems

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Tools

• CDP Port Reporter– Utility that provides quick reporting

of switch name, address, port identification

– Provides above information from point where EtherScope is connected to the LAN

– Cisco Discovery Protocol is used as the basis discovering; does not require SNMP to be enabled

– Designed to work in homogeneous environments

– Launched from within EtherScope application; runs and reports results from EtherScope console

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Channel metric definitions• Signal Strength - the average signal strength of all detected frames. Error, crosstalk and probe request

frames are not included. Display of dBm or percent values configured globally via Radio Settings.• Noise - the average channel noise value when any frame is detected (including error, crosstalk and probe

request frames).• Signal vs Noise - Signal strength value displayed on top along with the noise value on the bottom. • Signal to Noise Ratio - a measure of average signal strength relative to average noise. The ratio is always

displayed in dBm.• Good Packet Rate - The number of good frames detected. Error, crosstalk or retry frames are not included.• Error Packet Rate - The number of frames not received intact. Crosstalk or retry frames are not included.• Retry Packet Rate - The number of retransmitted frames detected. Error and crosstalk frames are not

checked for retry status.• Crosstalk Packet Rate - The number of frames detected on a channel that were actually transmitted on a

different channel. A frame must be received error free to be identified as crosstalk.• Good Octet Rate - The number of good frame octets detected.• Error Octet Rate - The number of frame octets not received intact.• Retry Octet Rate - The number of retransmitted frame octets detected.• Crosstalk Octet Rate - The number of frame octets detected on a channel that were actually transmitted on a

different channel.• Total Utilization % - The percentage of the channel's bandwidth that is being utilized by all frame

transmissions.• Retry % - The percentage of all detected frames on the channel that are retransmission frames.• Crosstalk % - The percentage of all detected frames on the channel that were actually transmitted on a

different channel.• Note: in Channels mode, these values are computed and updated for each channel scan period. In Channel

mode, these values are computed and updated once a second.

RFC 2544 Testing

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Service Level Agreement (SLA)• A contract between a network service provider and a

customer that specifies, usually in measurable terms, services the network service provider will furnish

• A service level agreement would typically contain the following information:– A description of the nature of service to be provided– The expected performance level of the service, specifically its

reliability and responsiveness– The procedure for reporting problems with the service– The time-frame for response and problem resolution– The process for monitoring and reporting the service level – he consequences for the service provider not meeting its

obligations– Escape clauses and constraints

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SLA and expected performance

• Performance metrics quantify end-user visible perceptions of service performance

• Typical performance metrics specified within a SLA– Throughput

• The maximum rate at which data can be transported from source to destination with zero lost frames

– Latency• The total time it takes for a frame to travel from source to destination. The context for a

relevant latency test is while the link is under load. The network needs to be able to deliver specified latency at specified utilization. RFC 2544 clearly states you have to do this test under the full throughput load

– Frame loss Test determines the percentage of frames that left the source but never reached the

destination. RFC 2544 recommends starting Frame Loss Rate tests at 100%, then stepping down to the next rate to test for lost frames. A successful test is defined by two consecutive tests without frame loss. Some frame loss rate tests waste time because they aren’t designed to terminate the test once this loss rate has been located.

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RFC 2544 testing

• IETF RFC 2544 “discusses and defines a number of tests that may be used to describe the performance characteristics of a network interconnecting device.”

• The RFC 2544 guidelines provide a standard testing methodology• RFC 2544 is optimized for testing single routing devices in a laboratory

environment• Not all the tests are applicable for providers installing or

troubleshooting Ethernet-based IP on active WAN links• 3 of the 6 tests specified by RFC 2544 are really necessary to

characterize performance in an Internet environment– Throughput– Latency– Frame Loss Rate

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RFC 2544 tests• While the RFC provides testing guidelines, implementations differ by

solution provider• Advantages of EtherScope’s implementation of RFC 2544

– Control over test configurations for predictability• User-defined parameters allow for tradeoffs between accuracy and test duration• Adaptive algorithms speed time to derive results

– Custom test suites for test automation• Fully characterize a single link by running multiple tests with varying parameters• Test multiple links from a single destination using multiple EtherScope remotes• Construct a test suite, click Start and all tests run automatically

– Accuracy for precise measurements• Latency measured with microsecond accuracy• Useful when characterizing single device performance

– Reports to document result

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RFC 2544 step by step

1. Define which test(s) to run2. Add device(s) (aka ES remotes)3. Configure tests4. Run tests (as one complete suite)5. Save results (graphs too)

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1. Define which test(s) to run

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2. Add device(s) (aka ES remotes)• Can differ by test• Same device multiple times with different configurations• Multiple devices to test several links

EtherScope Main

EtherScope R2

EtherScope R1

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3. Configure tests– Adjust parameters to tradeoff accuracy for quicker test completion– Adjust parameters (like CoS priority and IP TOS parameter) to

observe performance differences

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4. Run tests (as one complete suite)

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5. Save results (graphs too)

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RFC 2544 versus ITO

• EtherScope v3 features both RFC 2544 tests and ITO tests• RFC 2544 tests – use to fully characterize link performance

– Throughput [maximum rate at which none of the transmitted frames are dropped]

– Latency [total time it takes for a frame to travel from source to destination]

– Frame loss [percentage for frames lost throughout the range of test rates, starting at max rate and stepping down until rate with no lost frames is reached]

• ITO tests – use to quickly verify the throughput of a link– Throughput [measure frame loss at a user defined rate]– Traffic generator [generate network traffic, use to create different

loads to test performance]

Documents

EtherScope™ Series II Network Assistant Next generation network analyzer helps first responders solve problems fast ECA02132007