Hi, there.
Please check according to these steps:
1. Login WEB GUI, and check the
ONT port collected with STB was layer 3 port.

2. Check the IPTV has bonded LAN ports, and configured right Multicast Vlan ID.

3. Checking IPTV has got IP address.

4. Checking IGMP has been enabled, set IGMP mode as snooping or proxy.

Or

Check Layer 2 multicast issue
1. If ONT has this page, if not, just ignore it.

2. If ONT has this page, if not, just ignore it.

Troubleshooting this issue
1. Open lan-side telnet ONT

2. collect debug info
step 1: please execute these commands in order, and help us collect all the print information, and send to us.
WAP>display inner version
WAP>display deviceinfo
WAP>igmp get global cfg
WAP>igmp get iptv
WAP>igmp get port multicast config
WAP>igmp get debug switch
WAP>igmp get multilmac
WAP>igmp get statistics
step 2: open the BTV debug and check if ONT has received igmp packets.
WAP>igmp set debug switch enable 1 para 0
step 3: when you watch some programs, then you could use this command
WAP>igmp get multilmac
step 4: wait about 5 minutes, then close BTV debug.
WAP>igmp set debug switch enable 0 para 0
WAP>igmp get statistics
3. Export ONT configuration

4. Collect default Info

5. Collect all the print information and ONT configuration, default info.
Thanks.

