Triple-Play Service Deployment

Chapter 7: Troubleshooting Video Service in the Field
Video Service Quality Testing Procedures
Specific steps to ensure quality service delivery
Following is a concise overview of the actions a technician should
take to test video service quality thoroughly.
Analysis
Step Actions
1 Select a broadcast channel (IP address and port number) or select a VoD program (URL).
2 Initiate the signaling sequence:
(IGMP – Broadcast)
(RTSP – VoD)
3 Receive the requested program flow.
Analyze video and transport stream packets for QoS metrics:
Packet loss, jitter; lost packet distance and period; PCR jitter; PSI error count;
error indicator count
4 Compare metrics to thresholds established for network under test.
Note: if all pass this was a successful test. If any fail go to Step 5.
5 Initiate a second channel or VoD program flow.
6 Measure IGMP latency or RTSP latency with Pause/Play commands.
7 Receive second video flow, and analyze video QoS metrics.
Note: The two streams are being measured simultaneously
8 While analyzing video quality metrics analyze physical layer metrics on interface under test.
9 Compare packet loss events to physical layer error events.
Note: If no physical layer errors, packet loss is due to events northbound of network segment
under test.
10 Compare stream one metrics to stream two metrics.
Note: If any QoS thresholds fail in one stream, but not in the other, content and stream specific
issues are present.
Problem Resolution
11 Initiate a third stream.
12 Compare QoS metrics to thresholds for network.
Note: Thresholds are set to match a particular network.
13 Compare QoS metrics for stream 3 to streams 1 and 2. Look for differences related to items
pointing to content versus overall packet flow.
Note: Packet flow problems will affect all streams. All Channels versus One Channel is the key
concept to separate content issues from network issues.
191