Medianet: Quick Mediatrace Configuration Part 2

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Jul 21, 2011 9:49 PM
Jul 21st, 2011

This is part two of Medianet Mediatrace Overview. Mediatrace can be an effective ad-hoc troubleshooting tool that can help network support engineers troubleshoot network performance bottle necks that impact network traffic. It is also flexible enough to allow network planners to proactively monitor critical realtime applications and rich media traffic.  In this blog we will discuss the quick mediatrace configuration method and the three common methods to effectively diagnose network performance in our three router hop network.

The two available configuration methods for invoking mediatrace are quick and flexible. The underlining technology uses the same mechanism, however the configuration syntax between the two method varies. As the term "quick" implies, this method is best use to quickly diagnose a network performance problem in ad-hoc mode. The flexible method involves hierarchical configuration syntaxes that requires planning to proactively monitor critical applications.  We will discuss the flexible mediatrace configuration in part 3 of our medianet mediatrace blog, so please stay tuned.

In our lab, we're streaming a RTP video session of clock to a PC across our three router network. We will enable all three routers on the network to respond to mediatrace queries. The console on R2 will  present the single unified report that captures the video flow's performance as it traverses the network.

Screen shot 2011-07-18 at 11.28.20 PM.png

Despite the two methods for setting up a mediatrace in our network, all three routers in our lab must first be configured to respond to mediatrace queries. Each router  in our lab is configured with an SNMP community string. Mediatrace uses SNMP internally to collect interface statistics from each router.  Since R2 will present the results of the mediatrace on its console, R2 is configured to initiate the mediatrace poll using the loopback interface IP address.

Mediatrace Required Configuration

R1#conf t

R1(config)#mediatrace responder

R1(config)#snmp-server community public ro

R1(config)#snmp-server community private rw

R2#conf t

R2(config)#mediatrace responder

R3(config)#mediatrace initiator source-ip 10.87.80.145

R2(config)#snmp-server community public ro

R2(config)#snmp-server community private rw

R3#conf t

R3(config)#mediatrace responder

R3(config)#snmp-server community public ro

R3(config)#snmp-server community private rw

On R2, a mediatrace is initiated to poll the number of hops and the associated interface along the hops in which the video flow traverses. Mediatrace allows the operator to obtain various types of information regarding a specific video flow.  The command syntax in this example configures R2 to initiate a mediatrace poll to obtain device hops for the video flow path between the PC and the IP security camera in our lab.

Mediatrace for hops

R2#mediatrace poll path source 10.87.93.154 destination 10.87.93.164 hops

Started the data fetch operation.

Waiting for data from hops.

This may take several seconds to complete...

Data received for hop 0

Data received for hop 1

Data received for hop 2

Data fetch complete.

Results:

Data Collection Summary:

  Request Timestamp: 00:32:48.033 EST Fri Jul 22 2011

  Request Status: Completed

  Number of hops responded (includes success/error/no-record): 3

  Number of hops with valid data report: 3

  Number of hops with error report: 0

  Number of hops with no data record: 0

Detailed Report of collected data:

    Number of Mediatrace hops in the path: 3

    Mediatrace Hop Number: 0 (host=R2, ttl=255)

      Reachability Address: 10.87.80.50

      Ingress Interface: None

      Egress Interface: Tu1

    Mediatrace Hop Number: 1 (host=R3, ttl=254)

      Reachability Address: 10.87.93.45

      Ingress Interface: Tu0

      Egress Interface: Tu0

    Mediatrace Hop Number: 2 (host=R2, ttl=253)

      Reachability Address: 10.87.80.148

      Ingress Interface: Tu1

      Egress Interface: Gi0/1

The mediatrace poll hop results on R2 lists all the router hops and the corresponding interface the IP video flow traverse.

In the next example, R2 will be configured to poll interface statistics from each hop for the IP video flow between the PC and the IP video security camera.

Mediatrace for Interface Statistics

R2#mediatrace poll path source 10.87.93.154 destination 10.87.93.164 system

Started the data fetch operation.

Waiting for data from hops.

This may take several seconds to complete...

Data received for hop 0

Data received for hop 1

Data received for hop 2

Data fetch complete.

Results:

Data Collection Summary:

  Request Timestamp: 00:30:35.975 EST Fri Jul 22 2011

  Request Status: Completed

  Number of hops responded (includes success/error/no-record): 3

  Number of hops with valid data report: 3

  Number of hops with error report: 0

  Number of hops with no data record: 0

Detailed Report of collected data:

    Number of Mediatrace hops in the path: 3

    Mediatrace Hop Number: 0 (host=R2, ttl=255)

      Metrics Collection Status: Success

      Reachability Address: 10.87.80.50

      Ingress Interface: None

      Egress Interface: Tu1

      Metrics Collected:

        Collection timestamp: 00:30:35.975 EST Fri Jul 22 2011

        Octet input at Ingress (Bytes): NOT COLLECTED

        Octet output at Egress (MB): 1751.702777

        Pkts rcvd with err at Ingress (pkts): NOT COLLECTED

        Pkts errored at Egress (pkts): 0

        Pkts discarded at Ingress (pkts): NOT COLLECTED

        Pkts discarded at Egress (pkts): 12

        Ingress i/f speed (bps): NOT COLLECTED

        Egress i/f speed (mbps): 1000.000000

    Mediatrace Hop Number: 1 (host=R3, ttl=254)

      Metrics Collection Status: Success

      Reachability Address: 10.87.93.45

      Ingress Interface: Tu0

      Egress Interface: Tu0

      Metrics Collected:

        Collection timestamp: 00:30:35.988 EST Fri Jul 22 2011

        Octet input at Ingress (KB): 992355.994

        Octet output at Egress (KB): 631284.404

        Pkts rcvd with err at Ingress (pkts): 0

        Pkts errored at Egress (pkts): 0

        Pkts discarded at Ingress (pkts): 0

        Pkts discarded at Egress (pkts): 1

        Ingress i/f speed (mbps): 1000.000000

        Egress i/f speed (mbps): 1000.000000

    Mediatrace Hop Number: 2 (host=R1, ttl=253)

      Metrics Collection Status: Success

      Reachability Address: 10.87.80.148

      Ingress Interface: Tu1

      Egress Interface: Gi0/1

      Metrics Collected:

        Collection timestamp: 00:30:35.994 EST Fri Jul 22 2011

        Octet input at Ingress (MB): 3820.645292

        Octet output at Egress (KB): 441407.370

        Pkts rcvd with err at Ingress (pkts): 0

        Pkts errored at Egress (pkts): 6

        Pkts discarded at Ingress (pkts): 0

        Pkts discarded at Egress (pkts): 0

        Ingress i/f speed (bps): 100000

        Egress i/f speed (mbps): 1000.000000

The mediatrace system poll report on R2 lists all the router hops, in addition to the corresponding interface and its related statistics the IP video flow traverses. The interface packet statistics resembles the parameters on a Cisco IOS router's "show interface" output. When troubleshooting a network performance problem along multiple router hops, the mediatrace poll command using the "system" keyword can be used collect and present a consolidated report of all router interface statistics involved with routing media traffic. This method of collecting data on a single console helps support engineers avoid the labor intensive burden of logging into every device along a media path to manually verify interface statistics.

In the final mediatrace example, R2 will be configured to query the performance statistics for the specific IP video session between the PC in our lab and the IP video security camera. To collect as much detail as possible about the video flow, the mediatrace poll using the "perf-monitor" command includes the IP protocol type and OSI layer 4 port information as part of the syntax.

The results from the mediatrace performance monitor poll can help network operators answer  the question: "how well does our application perform on the network?"

Mediatrace for Performance Monitoring

R2#mediatrace poll path source 10.87.93.154 port 5000 destination 10.87.93.164 port 1790 ip-protocol udp perf-monitor

Started the data fetch operation.

Waiting for data from hops.

This may take several seconds to complete...

Data received for hop 0

Data received for hop 1

Data received for hop 2

Data fetch complete.

Results:

Data Collection Summary:

  Request Timestamp: 00:28:56.670 EST Fri Jul 22 2011

  Request Status: Completed

  Number of hops responded (includes success/error/no-record): 3

  Number of hops with valid data report: 3

  Number of hops with error report: 0

  Number of hops with no data record: 0

Detailed Report of collected data:

    Number of Mediatrace hops in the path: 3

    Mediatrace Hop Number: 0 (host=R2, ttl=255)

      Metrics Collection Status: Success

      Reachability Address: 10.87.80.50

      Ingress Interface: None

      Egress Interface: Tu1

      Metrics Collected:

        Flow Sampling Start Timestamp: 00:28:24

        Loss of measurement confidence: FALSE

        Media Stop Event Occurred: FALSE

        IP Packet Drop Count (pkts): 0

        IP Byte Count (KB): 16133.810

        IP Packet Count (pkts): 12469

        IP Byte Rate (Bps): 537793

        Packet Drop Reason: 0

        IP DSCP: 40

        IP TTL: 63

        IP Protocol: 17

        Media Byte Rate Average (Bps): 529481

        Media Byte Count (KB): 15884.430

        Media Packet Count (pkts): 12469

        RTP Interarrival Jitter Average (usec): 22874

        RTP Packets Lost (pkts): 0

        RTP Packets Expected (pkts): 12464

        RTP Packet Lost Event Count: 0

        RTP Loss Percent (%): 0.00

    Mediatrace Hop Number: 1 (host=R31, ttl=254)

      Metrics Collection Status: Success

      Reachability Address: 10.87.93.45

      Ingress Interface: Tu0

      Egress Interface: Tu0

      Metrics Collected:

        Flow Sampling Start Timestamp: 00:28:24

        Loss of measurement confidence: FALSE

        Media Stop Event Occurred: FALSE

        IP Packet Drop Count (pkts): 0

        IP Byte Count (KB): 16072.085

        IP Packet Count (pkts): 12422

        IP Byte Rate (Bps): 535736

        Packet Drop Reason: 0

        IP DSCP: 40

        IP TTL: 62

        IP Protocol: 17

        Media Byte Rate Average (Bps): 527454

        Media Byte Count (KB): 15823.645

        Media Packet Count (pkts): 12422

        RTP Interarrival Jitter Average (usec): 23240

        RTP Packets Lost (pkts): 0

        RTP Packets Expected (pkts): 12417

        RTP Packet Lost Event Count: 0

        RTP Loss Percent (%): 0.00

    Mediatrace Hop Number: 2 (host=R1, ttl=253)

      Metrics Collection Status: Success

      Reachability Address: 10.87.80.148

      Ingress Interface: Tu1

      Egress Interface: Gi0/1

      Metrics Collected:

        Flow Sampling Start Timestamp: 00:28:24

        Loss of measurement confidence: FALSE

        Media Stop Event Occurred: FALSE

        IP Packet Drop Count (pkts): 0

        IP Byte Count (KB): 16085.485

        IP Packet Count (pkts): 12432

        IP Byte Rate (Bps): 536182

        Packet Drop Reason: 0

        IP DSCP: 40

        IP TTL: 61

        IP Protocol: 17

        Media Byte Rate Average (Bps): 527894

        Media Byte Count (KB): 15836.845

        Media Packet Count (pkts): 12432

        RTP Interarrival Jitter Average (usec): 22647

        RTP Packets Lost (pkts): 0

        RTP Packets Expected (pkts): 12427

        RTP Packet Lost Event Count: 0

        RTP Loss Percent (%): 0.00

Analyzing the output on R2's console, we can quickly determine that no RTP packet drops occurred along the network path of the video flow. Further analysis of the show output indicates the DSCP value of each packet in the video flow as detected per each router hop.

Can you determine anything else of use from the output above?

Stay tuned for mediatrace part 3 where we will discuss flexible mediatrace configuration. With this option, network operation  engineers can build custom mediatrace parameters to proactively monitor network performance in their network. Until then, more information regarding mediatrace implementation can be found here:

Mediatrace Configuration Guide

http://www.cisco.com/en/US/docs/ios/media_monitoring/configuration/guide/mm_mediatrace.html

Cisco IOS Performance Monitor and Mediatrace QuickStart Guide

http://www.cisco.com/en/US/solutions/collateral/ns340/ns856/ns156/ns1094/whitepaper_c11-653899.html

Mediatrace Command Reference

http://www.cisco.com/en/US/docs/ios/media_monitoring/configuration/guide/mm_mediatrace.html

Medianet: Video Monitoring

https://supportforums.cisco.com/community/netpro/network-infrastructure/others/blog/2011/02/13/medianet--video-monitoring-1

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Posted July 21, 2011 at 9:49 PM
By eyu
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