Media Path Analysis
This section contains the
Analyzing Media Paths Using IP SLA
To start a proactive troubleshooting workflow:
Before You Begin
You can use this feature only if you have enabled the Cisco IOS IP Service Level Agreements (SLAs) on your network devices.
Cisco IOS IP SLA allow you to monitor network performance between Cisco devices (routers or switches). You must configure Cisco IOS IP SLAs Source and Responder in your network. You can verify whether the IPSLA responder feature is enabled on the device, using Prime Collaboration Assurance Device Work Center.
To understand and deploy the IP SLA on your network devices, see the IP Service Level Agreements (IP SLAs) technology page on Cisco.com.
||Perform the following:|
- Select the IP SLA source device from where you want to start the IP SLA testing.
- Select the IP SLA responder IP device, which is the IP SLA destination.
- Select the specific IP address of the responder IP device (applicable if your IP SLA destination device is configured with more than one IP address).
- Select the application for which you want to test the network performance.
voice-service dsp-reservation <percentage> command must be configured on the router that acts as IP SLA initiator, to collect IP SLA statistics from the router.
- Enter the IP SLA test life (in minutes).
IP SLA Test Result
Based on the IP SLA Test Life (Minutes) value that you enter, the IP SLA tool will generate the traffic for that duration. The IP SLA Test Result display data for:
The IP SLA Test Result includes:
- Latest result—Last time interval for which the operation was monitored. This depends on your configuration for frequency of monitoring on the device. Cisco IOS IP SLAs consumes CPU and memory. Most deployments use five-minute intervals, but some are one minute apart while others are 15 minutes apart.
- Last one hour aggregated result—Aggregated result for the last one hour.
- Flow Statistics for only video flow path is displayed in the path topology, if the device is configured as a mediatrace responder.
- Test Duration—Time interval for which the packets were monitored in seconds.
- Number of Tests Run—The number of times the IP SLA operation was run. This is based on the frequency of monitoring that you have configured on the device.
- One Way Latency—Average, minimum, and maximum latency values. These values are measured by sending RTP packets to IP SLAs Responder. The RTP (Real-Time Transport Protocol) data stream is then looped back from the destination, to the source gateway.
- Packets Lost—Number of packets lost. The source-to-destination value is measured by sending RTP packets to the IP SLAs Responder. No values are obtained from the digital signal processors (DSP) for this measurement.
- Inter-Packet Delay Variation (IPDV) (RFC 5481) Positive and Negative Jitter—Average, minimum, and maximum jitter values as calculated in RFC 5481.
- Last Updated—The time when the data was last updated.
The IPSLA result also provides details on the path through the Path Assessment tab. You can view the proactive troubleshooting summary information for testable devices, nontestable device, mediatrace-enabled devices, devices with packet loss threshold violation, devices with jitter threshold violation, and devices with DSCP violation.
A set of tests are run for the devices determined during proactive troubleshooting. To start the Path Assessment test, click Path Assessment Tests, after the proactive troubleshooting is complete for the session. For more information, see Path Assessment.
If the troubleshooting IP SLA statistics is not available, Prime Collaboration supports application diagnostics to diagnose the issues and understand the root cause and recommendation. Figure 1. IPSLA Test Result Failure
You must click Run Diagnostics. A message pops up stating the root cause and recommendation. After you run diagnostics, Prime Collaboration can diagnose if:
Figure 2. IP SLA Diagnostics Root Cause and Recommendation
- The device supports IP SLA video operations.
- Prime Collaboration has CLI access to the device.
- IP SLA configuration is provisioned for the session running.
- The To device has IP SLA responder role configured.
- NTP clock is synchronized.
- The To device is reachable via the From device.
- voice-service dsp-reservation command is configured on the From device, if it is a router.
Analyzing Media Paths Using VSAA
To perform media
Before You Begin
has the capability to facilitate the readiness assessment of a network to
deploy Cisco Video or TelePresence systems. The Video SLA Assessment Agent
(VSAA) is used in Prime Collaboration to provide network path characteristics
(that is, latency, jitter, and packet loss) metrics before deploying or
upgrading Cisco Video, TelePresence, or IP Video Surveillance (IPVS) systems
and site extensions.
The agent helps to
determine network issues proactively, facilitating the expected rich quality
and experience of Cisco TelePresence systems after its deployment. The benefits
of the VSA Agent include accelerated Cisco TelePresence systems deployment and
reduction in effort and time through automation of the assessment process and
You can download the
VSA Agent software from the Prime Collaboration
software download site
on Cisco.com. See
Video SLA Assessment Agent
3.1 Installation Guide for the installation guidelines.
Verify that the VSA Agent is
up and running at the two endpoints, and synchronized to the NTP server.
||Enter the required assessment
Table 1 Profile Details
Displays the profile settings
you want to assess. RTP packets sent will be of based on the device type.
Number of devices or streams
you want to add to the network. You can add upto five devices.
DSCP value indicates priority
to traffic quality. The highest quality DSCP value is selected to ensure good
quality video streaming.
You must use CTS1000 profile
to deploy CTS 500 and 1000 and CTS3000 profile to deploy CTS 3000. You can
create, edit, and delete profiles.
VSA Agent Assessment Results
For the individual streams, you can view the topology (layer 2 and layer 3) for the selected direction between endpoints in the Troubleshooting tab.
You can view the detailed troubleshooting workflow status for the top level and the individual streams using the Log tab. The Medianet Path View contains output from each mediatrace enabled device. The VSA Agent Assessment result also provides details on the path through the Path Assessment tab. You can view the troubleshooting summary information for testable devices, nontestable device, mediatrace-enabled devices, devices with packet loss threshold violation, devices with jitter threshold violation, and devices with DSCP violation.
A set of tests are run for the devices determined during troubleshooting. To start the Path Assessment test, click Path Assessment Tests, after the proactive troubleshooting is complete for the session. For more information, see Path Assessment.
The Test Result tab displays the following charts. For these charts, only the results of last twenty tests are displayed.
Peak-to-Peak JitterFigure 4. Peak-to-Peak Jitter Graph
Packets LostFigure 5. Packets Lost Graph
Managing a Video Test Call
You can create point-to-point
video test calls between two video endpoints in managed state, to test your
network. You can see events and alarms, session statistics, endpoint
statistics, and network topology with medianet statistics like other calls.
Only the CTS, C and EX series codecs are supported for this call.
- This feature is not supported
for E20 codec series.
- To use this feature, CLI
credentials must be added for the endpoints.
- Ensure that the endpoints
are registered and JTAPI is enabled for endpoints (if they are registered to
Table 2 Managing a Video
video test call from Endpoint Diagnostics (Under Operate)
video test call from Session Diagnostics (Under Operate)
video endpoints, and click Video Test Call, to create a test call between two
- This button gets enabled only
after you have selected two video endpoints.
- You cannot create a video
test call by selecting more than two endpoints.
particular session on the Session Diagnostic page, and click
Video Test Call, to create a test call for that
button gets activated only after you select a scheduled session. To see the
list of the list of scheduled sessions, filter for scheduled sessions. Remember
to select a session for a future time and date only.
The Add Test
Call pop up window appears, where you can click on the IP address of the
endpoint to launch its application. The default option is to run the test call
immediately but you can schedule the call also.
endpoints select the SIP protocol only. For Ex and C Series endpoints you can
choose between H.323 and SIP protocols, provided these endpoints are registered
using these protocols. When you click the Add Call button, a message appears to
notify you that the call has been added successfully.
scheduled call details can be seen on the Session Diagnostics page. You can see
events and alarms, session statistics, endpoint statistics, and network
topology with medianet statistics like other calls. This information is
available for completed test calls also. You can stop the call immediately if
it causes a problem on the network.
running video test call
You can stop
a video test call which is in progress if it hampers your network. To stop a
call, select the test call from the Sessions Diagnostic page, by setting the
filter to Test Call Sessions. Hover around the session subject to launch the
360° Session View, and click the Stop Call icon to stop the in progress video
lasts for around 5 minutes, after which it automatically stops.
scheduled video test call from Video Test Call Configurations page
You can also
view or delete video test calls from the same page.
To edit a
video test call, click
Edit, and reschedule or run the call immediately by
Save. A message appears to notify you that the call
has been modified successfully.