Testing Telepresence Network Quality Before Starting a Telepresence Video Conference
Background
If a telepresence network does not meet the quality requirements for a telepresence video conference, the telepresence video conference cannot be held successfully. To prevent this problem, test the delay, jitter, and packet loss ratio of the telepresence network before you start a telepresence video conference, identify network segments with poor link quality, and take corrective measures:
To prevent audio or image delay, perform a delay test on the telepresence network to identify network segments with poor link quality and take corrective measures. To perform a delay test, configure a Real-Time Transport Protocol (RTP) test instance on the source node and configure an RTP User Datagram Protocol (UDP) server on the intermediate and destination nodes.
To prevent fuzzy or discontinuous images, perform jitter and packet loss ratio tests on the telepresence network to identify network segments with poor link quality and take corrective measures. To perform jitter and packet loss ratio tests, configure an RTP test instance on the source node and configure an RTP snoop test instance on the intermediate and destination nodes.
In Figure 6-25, SwitchA is the source node, SwitchD is the destination node, and SwitchB and SwitchC are intermediate nodes.
Configuration Procedure
- Performing a Delay Test
Configure an RTP test instance on the source node to send RTP packets.
- Run system-view
The system view is displayed.
- Run nqa test-instance admin-name test-name
An NQA test instance is created and the test instance view is displayed.
- Run test-type rtptest
The test instance type is set to rtptest.
- Run destination-address ipv4 ip-address
The destination port IP address for the RTP test instance is set.
- Run destination-port port-number
The destination port number for the RTP test instance is configured.
- Run source-address ipv4 ip-address
The source port IP address for the RTP test instance is configured.
- Run source-port port-number
The source port number for the RTP test instance is configured.
- (Optional) Run the following commands to configure other parameters
for the RTP test instance:
Run vpn-instance vpn-instance-name
A virtual private network (VPN) instance is configured for the RTP test instance.
Run tos tos
The type of service (ToS) is configured.
Run duration duration
The test duration is configured.
Run rate { rate | packet-size packet-size interval interval-value }
The traffic rate is configured.
Run protocol-type { udp | tcp }
The protocol type is configured.
- Run description string
A description is configured.
Run start now
The RTP test instance is started.
Run stop
The RTP test instance is stopped.
- Run system-view
- Configure an RTP-UDP server on the intermediate and destination
nodes.
- Run system-view
The system view is displayed.
Run the nqa-server rtp-udp [ vpn-instance vpn-instance-name ] ip-address port-number command or nqa-server rtp-tcp [ vpn-instance vpn-instance-name ] ip-address port-number command based on the configured protocol type.
An RTP server is configured.
The IP address and port number of the server must be the same as the destination IP address and port number configured on the source node.
A device can function both as the source node of a test instance and a server of another test instance. In this case, ensure that the source IP address and port number of the source node are different from the server's IP address and port number.
The server simulates RTP data streams of the source to respond to the source. Therefore, the 802.1p priority and DSCP priority of response packets sent from the server are the same as those of the packets sent from the source, but not the values configured using the set priority { 8021p 8021p-number | dscp dscp-number } command.
- Run system-view
- Performing Jitter and Packet Loss Ratio Tests
Configure an RTP test instance on the source node to send RTP packets. Configuring an RTP test instance for jitter and packet loss ratio tests is similar to configuring an RTP test instance for a delay test.
Configure an RTP snoop test instance on the intermediate and destination nodes.
- Run system-view
The system view is displayed.
- Run nqa test-instance admin-name test-name
An NQA test instance is created and the test instance view is displayed.
- Run test-type rtpsnoop
The test instance type is set to rtpsnoop.
- Run destination-address ipv4 ip-address
The destination port IP address for the RTP snoop test instance is set.
- Run destination-port port-number
The destination port number for the RTP snoop test instance is configured.
- Run source-address ipv4 ip-address
The source port IP address for the RTP snoop test instance is configured.
- Run source-port port-number
The source port number for the RTP snoop test instance is configured.
The destination port number and IP address and source port number and IP address for the RTP snoop test instance must be the same as those configured for the RTP test instance.
- (Optional) Run the following commands to configure other parameters
for the RTP snoop test instance:
- Run description string
A description is configured.
Run duration duration
The test duration is configured.
Run protocol-type { udp | tcp }
The protocol type is configured.
- Run description string
Run start now
The RTP snoop test instance is started.
Run stop
The RTP snoop test instance is stopped.
- Run system-view
