Medianet Reference Guide - Cisco

Chapter 6
Medianet Management and Visibility Design Considerations
Cisco Network Analysis Module
traceroute is run, although different IP addresses corresponding to different interfaces are returned, and
the list of devices is reversed. Therefore, you need to run the traceroute in only one direction to
understand the media flows in both directions. However, note that this may not necessarily be the case
in a network with multiple equal-cost paths. Also note that the CTS-1000 does not return ICMP Time
Exceeded packets, and therefore the traceroute utility times out. For a TelePresence endpoint, this can
be rectified by directing the traceroute to the IP Phone associated with the TelePresence endpoint.
However, be aware that some video endpoints may not respond to UDP traceroute packets with ICMP
Time Exceeded packets.
Single-path non-redundant IP network infrastructures are somewhat counter to best practices for
network designs with high availability in mind. Unfortunately, the use of traceroute within an equal-cost
redundant IP network infrastructure can sometimes return unclear results regarding the path of an actual
video flow between two endpoints. An example of why this occurs can be seen with the output of two
traceroute commands run on a Cisco Catalyst 4500 Series switch to a TelePresence Cisco TelePresence
Multipoint Switch (IP address 10.17.1.20), as shown in Example 6-10.
Example 6-10
Example Output from the Traceroute Utility
me-westcamp-1#traceroute
Protocol [ip]:
Target IP address: 10.17.1.20
Source address: 10.24.1.1
Numeric display [n]: yes
Timeout in seconds [3]:
Probe count [3]: 4
Minimum Time to Live [1]:
Maximum Time to Live [30]: 10
Port Number [33434]:
Loose, Strict, Record, Timestamp, Verbose[none]: v
Loose, Strict, Record, Timestamp, Verbose[V]:
Type escape sequence to abort.
Tracing the route to 10.17.1.20
1 10.17.100.37 8 msec 0 msec 4 msec 0 msec
2 10.17.100.17 0 msec 0 msec 4 msec 0 msec
3 10.17.100.94 0 msec 0 msec 0 msec 0 msec
4 10.17.101.10 4 msec 0 msec 0 msec 0 msec
5 10.17.101.13 0 msec 4 msec 0 msec 0 msec
6 10.17.1.20 0 msec 4 msec 0 msec 0 msec
me-westcamp-1#traceroute
Protocol [ip]:
Target IP address: 10.17.1.20
Source address: 10.26.1.1
Numeric display [n]: yes
Timeout in seconds [3]:
Probe count [3]: 4
Minimum Time to Live [1]:
Maximum Time to Live [30]: 10
Port Number [33434]:
Loose, Strict, Record, Timestamp, Verbose[none]: v
Loose, Strict, Record, Timestamp, Verbose[V]:
Type escape sequence to abort.
Tracing the route to 10.17.1.20
1 10.17.100.37 0 msec 0 msec 0 msec 0 msec
2 10.17.100.29 4 msec 0 msec 0 msec 0 msec
3 10.17.100.89 0 msec 4 msec 0 msec 0 msec
4 10.17.101.10 0 msec 0 msec 0 msec 4 msec
5 10.17.101.13 0 msec 0 msec 0 msec 4 msec
6 10.17.1.20 0 msec 0 msec 0 msec 0 msec
OL-22201-01
Medianet Reference Guide
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