The IPTV MPEG inline test lets you monitor the quality of TV channels that customers are watching. When you start this test, Netrounds will start listening to the IGMP signaling (IGMPv2 is supported, whereas IGMPv3 is not) and measure on the channels that the set-top box joins. Measurements include MPEG loss, PCR jitter and data rate; Netrounds will also alert you about any general problems with the stream.
Note: Netrounds will only measure on channels that are on its preconfigured IPTV channel list (see this page). If a set-top box joins a channel that is not present in Netrounds' channel list, no measurement data will be obtained. Note also that Netrounds does not decrypt any of the MPEG streams, but utilizes only the unencrypted MPEG headers for quality measurements.
It is possible to configure a threshold for the IPTV PAT/PMT receive interval, that is, define how frequently PAT and PMT information should be detected in the received stream. Note that this overrides the default frequency of two PAT/PMT packets per second, as specified in ETSI TR 101 290 (Measurement guidelines for DVB systems).
Setting up a test or monitoring
To do IPTV inline measurements you need to have at least one Netrounds Test Agent installed. If you haven't already done the installation, consult our quick start guides for various types of Test Agents in the section Netrounds Test Agents.
To prepare for IPTV inline testing, first create a bridge interface and connect it between the residential gateway (CPE) and the customer set-top box (STB).
Also, as noted above, make sure that you have configured Netrounds with your IPTV channel list.
Then create a new test or monitoring and fill in the mandatory parameters below:
- Duration (seconds): The duration of this test step in seconds. Min: 30 s. Max: 604800 s. Default: 60 s.
- Fail threshold (seconds): The maximum number of errored seconds (ES) that may occur without triggering a fail for this test step. Default: 0.
- Wait for ready: Time to wait before starting the test. The purpose of inserting a wait is to allow all Test Agents time to come online and acquire good time sync. Min: 1 min. Max: 24 hours. Default: "Don't wait", i.e. zero wait time.
- Clients: Test Agents on which you want to receive IPTV channels. Note: A prerequisite for this test is that the Test Agents have a bridge interface.
Thresholds for errored seconds (ES)
- MPEG loss: Maximum tolerated MPEG packet loss (CC errors) per second. Default: 2 packets per second.
- Jitter: Maximum tolerated jitter (delay variation) in the received streams. Default: 50 ms.
- PAT/PMT interval (s): Maximum tolerated interval between PAT/PMT transmissions. Min: 0.5 s. Max: 60 s. Default: 0.5 s. Note: PAT/PMT should be received every half-second on a program according to the standards.
- PID interval (s): Maximum tolerated interval between audio or video PIDs as specified by PMT. Min: 1 s. Max: 60 s. Default: 5 s. Note: On regular audio/video streams, a PID should be received every 5 seconds according to the standards.
- Delayed start (s): (Tests only) Time by which to delay the start of the test within a test step. Default: 0 s.
SLA thresholds (monitorings only)
- SLA Good: Threshold for good fulfillment of service level agreement. Default: 99.95%.
- SLA Acceptable: Threshold for acceptable fulfillment of service level agreement. Default: 99.5%.
- Rate (Mbit/s): The bit rate of the MPEG program stream.
- Transport rate (Mbit/s): The bit rate of the MPEG transport stream (MPEG-TS), that is, the rate of the MPEG stream including the overhead from the header of the Transport Stream packet.
- MPEG loss: MPEG packet loss, calculated from the Continuity_count_error counter in the MPEG stream.
- PCR jitter (ms): The jitter (delay variation) of the received MPEG stream. Calculated from the timestamps in the Program Clock Reference (PCR) field transmitted in the adaption layer of the MPEG transport stream.
- RTP jitter, loss, misorders: If the stream contains RTP headers, Netrounds will calculate RTP jitter, loss, and misorders, which are basically the same as the corresponding metrics for IP. Whether or not the stream contains RTP headers depends on the encoder at the head-end.
- PAT errors: A PAT error is triggered if a Program Allocation Table (PAT) is not received on a multicast group within PAT/PMT interval.
- PMT errors: A PMT error is triggered if a Program Map Table (PMT) is not received on a multicast group within PAT/PMT interval.
- PID errors: On regular audio/video streams, a frame should be received in every PID interval. If no frame is received within that interval, one PID error is generated for each further second that elapses from that point.
- ES MPEG loss: Number of errored seconds triggered by MPEG loss exceeding the MPEG loss threshold during one second.
- ES jitter: Number of errored seconds triggered by PCR jitter or RTP jitter exceeding the Jitter threshold.
- ES invalid stream: An aggregate of PAT, PMT, and PID errors. If any of these types of error is encountered during a second, it is marked as an Invalid stream errored second.
- ES total: Aggregated errored second percentage, taking into account all types of error.
- SLA: Service level agreement fulfillment for the test or monitoring: equal to (100 – ES total) %.