Issue description A fault was reported by the customer about the IPTV Headend Switch receiving a large number of multicast request packets from different IPTV channels of an OLT, which caused an IPTV service degradation of the entire frame.
Handling Process Below is the troubleshooting procedure.
1. The
GPON OLT resources were checked and found normal. CPU Memory utilization was found under the normal range.
CPU memory 2. After the above step, debug logs of the OLT were collected and checked. 4609 irrelevant static multicast program IPs configured on OLT as per the below logs of OLT.
3. The correct static multicast program IPs are 310 in count, whose range is from xx.xxx.x.x to xxx.xxx.x.250 and xxx.xxx.x.1 to xxx.xxx.x.60, but this OLT was configured with 4609 irrelevant static multicast program IPs, starting from xxx.xxx.x.61 to xxx.xxx.xx.60, which were sending huge request packets to third party IPTV switch. Third-party IPTV switch encountered with huge request packets storm causing IPTV service degradation.
4. Upon the above findings, irrelevant static multicast program IPs were deleted from OLT to resolve the problem.
Root cause Irrelevant multicast request packets were sent by the OLT to third-party IPTV switch due to irrelevant static multicast program IP configuration on OLT.
In the current working scenario, general query messages are sent by the upper layer (third party Headend side) IPTV platform to the OLT. In response to the query messages, IGMP report messages are sent by OLT to the (third party Headend side) IPTV platform to inform the intention to get the multicast stream. Since the OLTs are directly connected to the uplink
NE40E core router, PIM (multicast protocol) is configured on the respective P2P NE40 interface to support OLT requests.
Report message count depends on the count of static IGMP programs configured at OLT. Larger static IGMP programs at the OLT side will ultimately increase the count of report requests from OLT to the upper layer (third-party Headend side) IPTV platform. Third-party IPTV switch encountered with huge request packets storm causing IPTV service degradation.
Solution After the deletion of irrelevant static multicast program IPs from OLT, the problem was resolved.
