multiple streams testing using the fst-2802 testpad...using the multiple streams option for the...

Multiple Streams Testing Using the FST-2802 TestPad

Introduction

The JDSU FST-2802, a member of the TestPad family of products, is a rugged, battery-operated testinstrument that enables field technicians to turn up and maintain Ethernet, IP, and Fibre Channelservices. The testing capabilities of the FST-2802 range from BER testing and verifying end-to-endconnectivity to determining throughput, link usage, and round trip delay (RTD). The instrument’s pingand trace route capabilities enable technicians to verify both the path and the connectivity of a link overan IP-routed network. Additionally, a new login feature for Fibre Channel enables technicians to testboth full and subrate links with BER patterns and test traffic. The easy-to-use graphical user interface(GUI) of the FST-2802 allows technicians, with limited Ethernet, IP, or Fibre Channel testingexperience, to verify performance parameters and ensure that the services conform to service levelagreements (SLAs). Furthermore, optional automation of RFC 2544 testing is available with improvedgraphical results and reporting capabilities.

With the new Version 7.0 software release, the FST-2802 now offers technicians class of service testingwith the ability to specifically test individual voice, video, and data streams over a single link. With themultiple streams option for the FST-2802, technicians can:

- Generate multiple traffic streams with different VLAN IDs, user priorities, source and destination addresses, TOS/DSCPs, frame sizes, or utilizations per stream

- View the results of each stream independently and immediately recognize errors

- Capture and display the utilizations of up to eight VLAN ID and user priority pairs

- Capture and display the utilizations of up to eight IP source and destination addresses

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Application Note

Multiple Streams Traffic Generation and Testing

The latest enhancement of the FST-2802, the multiple streams option, enables technicians to generateup to eight fully independent traffic streams for each physical port of the FST-2802. Therefore, a dual-port unit can generate up to sixteen different traffic streams independently and show statistics foreach stream. This enhancement leads to new testing applications using the FST-2802. Several newtesting applications are discussed in this document.

True Class of Service Testing

Many service providers are beginning to offer different classes of services, whereas customers who paymore get a higher priority traffic stream and a different service level agreement than customers who payless. This new offering leads to a new type of problem where the latency and loss may be acceptable forregular traffic, but the higher priority traffic does not meet its required SLA.

In order to test these new networks, technicians can use the new multiple streams option for the FST-2802 to oversubscribe the switch and determine if the various SLAs are met. This is accomplishedby using two or three different traffic streams of differing priorities and sending more traffic throughthe switch than it can handle. For example, a technician can attempt to send 1000 Mb/s of trafficthrough an OC-3 SONET ring. The switch should drop the lower priority traffic, but it should allow allof the higher priority traffic to pass through to the far end where another FST-2802 (or the second portof a dual-port unit) is connected to the receiver (Figure 1).

The multiple streams option allows technicians to set a different destination MAC address, VLAN ID,and user priority for each independent traffic stream (Figure 2).

2Application Note: Multiple Streams Testing Using the FST-2802 TestPad

FST-2802

1G Ethernet

FST-2802

1G EthernetOC-3 / STM-1

Figure 1. Class of service testing using the multiple streams option for the FST-2802.

Figure 2. Setting the destination MAC address, VLAN ID, and user priority for a traffic stream.


Furthermore, the IP option combined with the multiple streams option enables technicians to setdifferent IP or TOS/DSCP addresses for each independent traffic stream (Figure 3).

A summary screen shows the relevant settings for each stream and allows technicians to set thebandwidth utilization percentage for each independent traffic stream (Figure 4).

Once the parameters of the different traffic streams are set, the switch will begin to drop traffic. Moreimportantly, though, the switch should only drop traffic on the low priority streams. Since the FST-2802 can display the results for all of the individual traffic streams (Figure 5), technicians canquickly determine if the switch is behaving properly.

Figure 3. Setting the IP and TOS/DSCP addresses for a traffic stream.

Figure 4. Setting the bandwidth utilization percentage for each traffic stream.

Proper switch behavior can be verified by analyzing the individual traffic stream results (Figure 6) anddetermining if the stream’s test results, including frame loss, RTD, utilization, and frame counts, are inconformance with the SLA or other test requirements.

Testing Multiple Routes Simultaneously

The multiple streams option for the FST-2802 also enables technicians to test two routes between thesame origination point and the same destination point on the same physical link. If a technicianmeasures different delays on the two parallel routes, the FST-2802 can be used to establish two virtualLAN (VLAN) connections to a remote site. This allows the technician to verify RTD in order todetermine if the delay is identical on both routes. The multiple streams option can also be used to testa “hub and spoke” configuration, where the same FST-2802 is used to transmit frames to multipledifferent physical locations. In this manner, multiple paths can be brought into service quickly andsimultaneously.


Figure 6.Verifying proper switch behavior by analyzing the individual traffic stream results.

Figure 5.The summary results screen displays the results for all traffic streams.


Traffic Prioritization and Mapping Tests

A switch is often set to map a particular VLAN or TOS/DSCP configuration to a specific port. Forexample, a switch may be configured so that all traffic that arrives from VLAN ID 2 is sent out oncustomer port 5. In order to test that the switch has been properly provisioned, a technician cangenerate traffic with the appropriate VLAN tag or TOS/DSCP field and verify that the traffic is routedto the correct outbound port. Using the multiple streams option for the FST-2802, technicians cangenerate multiple streams of traffic with different VLANs through the switch. The other FST-2802 (orthe second port of a dual-port unit) can then be used to receive the traffic and can verify that the VLANtraffic, which was mapped to the outbound port, was sent through the switch.

Tx Rx Tx Rx

FST-2802

Test (1)

RFC 2544

Test (2)

RFC 2544

Port 2Port 1

Figure 7. Switch wrap testing of a circuit.

Switch Wrap Testing

The dual-port FST-2802 (or two single-port FST-2802s) also supports switch wrap testing, enablingtechnicians to pre-qualify a switch before bringing it into service. This is generally accomplished byconnecting the FST-2802 to two separate ports on either side of the backplane, at the client side and thenetwork access side, and then generating full 1G line rate traffic through the switch (Figure 7). Thetechnician generates traffic from the client or the network side through to the FST-2802 and then sendsthat signal back to the originating side using the FST-2802’s loopback capability. This test is useful forstressing the throughput of the line card and the switch backbone in order to ensure that the equipmentmanufacturer has met the required specifications.

A dual-port FST-2802 is also useful for testing subrate line cards. For example, technicians can connectone FST-2802 port to the 10/100 line card and the other FST-2802 port to the Gigabit line card andperform throughput testing.

In-Service MonitoringOn occasion, a circuit, which is tested using traffic generated from an FST-2802, meets specificationsduring out-of-service testing; however, a fault may persist once the customer’s equipment isreconnected. In these cases, or in cases where out-of-service testing is not an option, it becomesnecessary to monitor the circuit while it is in service. The dual-port FST-2802 provides a "through-mode" capability, enabling traffic to pass through it without disrupting the service (Figure 8).

In-service monitoring allows technicians to first monitor the link and determine if there are any errorson that portion of the link. The purpose of this testing is to determine if a problem exists between twoswitches. If a problem exists between the two switches, an error will be detected on that portion of thelink.

Furthermore, the FST-2802 is capable of automatically filtering incoming traffic, based upon VLAN ID,user priority, MAC address, or IP address, allowing technicians to determine if the appropriatecustomer traffic is being transmitted properly throughout the network. For example, consider acustomer on VLAN ID 2, who purchased a service level agreement of 50 Mb/s. When monitoring thein-service link, the technician can determine if the customer traffic is over 50 Mb/s or if the customeris not getting the agreed upon bandwidth. Technicians can also set filters on source and destinationMAC addresses, TOS/DSCP, and other fields to help determine if a difficult configuration problemexists on the network.


Tx Rx

CPE

Service

Provider's

Network

Tx Rx

FST-2802

Port 2Port 1

Figure 8. In-service monitoring of a circuit.


VLAN Discovery

The new multiple streams option for the FST-2802 allows technicians to further troubleshoot the linkby providing them with the ability to discover different problems that are occurring on the network ineither MON (single-port) or THRU (dual-port) modes. The VLAN discovery feature automaticallydiscovers the VLAN ID and VLAN priority pairs that exist on the link and displays the currentthroughput for each pair. This information is useful, for example, when two customers share a link andboth of them are complaining of slow throughput, but no problems are found on the network elements.A technician can monitor the traffic streams coming from both customers and determine if onecustomer is oversubscribing their bandwidth, causing problems on the link. In this case, the oversub-scribing customer would be encouraged to purchase more bandwidth in order to meet their growingneeds.

IP Discovery

The IP discovery feature functions similarly in that it allows technicians to automatically discover thefirst eight source and destination IP pairs on a link and displays the appropriate throughput associatedwith each pair (Figure 9). Using the IP discovery feature, network administrators can use the FST-2802to determine if a top talker, which is overrunning the bandwidth on the link and causing problems forthe other customers, exists on the network (Figure 10).

Figure 9. Using the IP discovery feature of the FST-2802.

Figure 10. Setting the parameters for IP traffic filtering.

IPDSLAM Turn-up TestingA relatively new requirement for service providers is the ability to turn up and test network elementsthat are going to be placed in the field for video deployment. The common characteristic of thesenetworks is that an Ethernet link is connected to the DSLAM where it is dropped as VDSL or ADSL2+to the customer. A dual-port FST-2802 can be used to test this network scenario using a modem orresidential gateway to convert the VDSL or ADSL2+ signal to 100 Mb/s Ethernet (Figure 11).

Using a modem and a dual-port FST-2802, one technician can efficiently test connectivity, throughput,and quality of service (QoS) through the IPDSLAM. The advantage of this testing is to ensure that theequipment has been properly provisioned in the field prior to carrying customer traffic across the link.Furthermore, using the multiple streams option, technicians can specify voice, video, and data traffic,which can then be individually tested and verified against the customer SLA.


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tion believed to be reliable or accurate. However, the accuracy or completeness thereof is not guaranteed, and no

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property claims of others. Please contact JDSU for more information. JDSU and the JDSU logo are trademarks of

JDS Uniphase Corporation. Other trademarks are the property of their respective holders. ©2006 JDS Uniphase

Corporation. All rights reserved. 30137417 000 0106 FST2802.AN.ACC.TM.AE

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FST-2802

GigE

10/100

Ethernet

VDSL

IPDSLAMModem

Figure 11. IPDSLAM turn-up testing of a circuit.

multiple streams testing using the fst-2802 testpad...using the multiple streams option for the...

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