Medianet Reference Guide - Cisco

Chapter 6
Medianet Management and Visibility Design Considerations
Cisco Network Analysis Module
Number of Jitter Samples: 16490
Source to Destination Jitter Min/Max: 1/4
Destination to Source Jitter Min/Max: 1/6
Source to destination positive jitter Min/Avg/Max: 1/1/4
Source to destination positive jitter Number/Sum/Sum2: 440/457/505
Source to destination negative jitter Min/Avg/Max: 1/1/4
Source to destination negative jitter Number/Sum/Sum2: 496/512/558
Destination to Source positive jitter Min/Avg/Max: 1/1/6
Destination to Source positive jitter Number/Sum/Sum2: 571/587/679
Destination to Source negative jitter Min/Avg/Max: 1/1/6
Destination to Source negative jitter Number/Sum/Sum2: 513/529/621
Interarrival jitterout: 0 Interarrival jitterin: 0
Packet Loss Values
Loss Source to Destination: 0 Loss Destination to Source: 0
Out Of Sequence: 0 Tail Drop: 0 Packet Late Arrival: 0
Number of successes: 10
Number of failures: 0
Failed Operations due to over threshold: 0
Failed Operations due to Disconnect/TimeOut/Busy/No Connection: 0/0/0/0
Failed Operations due to Internal/Sequence/Verify Error: 0/0/0
Distribution Statistics:
Bucket Range: 0-19 ms
Avg. Latency: 1 ms
Percent of Total Completions for this Range: 100 %
Number of Completions/Sum of Latency: 10/10
Sum of RTT squared low 32 Bits/Sum of RTT squared high 32 Bits: 10/0
Operations completed over thresholds: 0
For the example above, the IPSLA responder was an actual Cisco TelePresence CTS-1000. Only IPSLA
responder operations can be configured on Cisco TelePresence System endpoints; they cannot function
as IPSLA sources. Configuration is only via the SSH CLI, as shown in Example 6-5.
Example 6-5
IPSLA Responder Configuration on a CTS-1000
admin: utils ipsla responder initiators add net 10.16.1.0/24
admin: utils ipsla responder enable start
The configuration above enables the IPSLA responder function for initiators (senders) on the
10.16.1.0/24 subnet. This corresponds to the source of the IPSLA packets from the Cisco Catalyst 6500.
By default, the range of ports enabled on the CTS-1000 is from 32770 to 33000. However, the port range
can be enabled by including start and end ports within the utils ipsla responder enable command. For
a discussion of all the commands available via the SSH CLI, including all the IPSLA commands, see the
Cisco TelePresence System Release 1.6 Command-Line Interface Reference Guide at the following URL:
http://www.cisco.com/en/US/docs/telepresence/cts_admin/1_6/CLI/cts1_6cli.html.
The use of IPSLA as a pre-assessment tool can be disruptive to existing traffic on the IP network
infrastructure. After all, the objective of the pre-assessment test is to see whether the network
infrastructure can support the additional service. For example, if a particular link within the network
infrastructure has insufficient bandwidth, or a switch port has insufficient buffering capacity to support
existing TelePresence traffic as well as the additional traffic generated from the IPSLA pre-assessment
tests, both the existing TelePresence call and the IPSLA operation show degraded quality during the
tests. You must therefore balance the possibility of temporarily degrading production services on the
network against the value of the information gathered from running an IPSLA pre-assessment test during
normal business hours. Running the IPSLA tests after hours may not accurately assess the ability of the
network to handle the additional service, because after-hour traffic patterns may vary significantly from
traffic patterns during normal business hours. Further, running a successful pre-assessment test after
hours may lead to the installation of a production system that then results in degraded quality both for
itself and for other production systems during normal business hours.
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Medianet Reference Guide
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