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Multicasting - Freezing


Userlevel 1
I am connecting TRIAX STB A235-N1x-hd setup box with X440 switch and also the receiver to do L2 multicasting but it freezes after 4-5 minutes and resumes once I restart the setup box. I tried disconnecting/connecting the cable from switch and restarting the switch but it does'nt work. I have to restart the setup box to resume the freeze. I also tried changing the timers of igmp and igmp snooping but in vain. Please help

11 replies

Userlevel 6
Check if the receiver subscribes to the stream and when the stream stops if it is still subscribed (show igmp snooping detail). Check the logs, the X440 does not have much table space for multicasting and you might need to apply actions in below article to improve the multicast behavior.
https://gtacknowledge.extremenetworks.com/articles/How_To/Multicast-Entry-not-Added-Hardware-Table-F...
Userlevel 1
There is no multi-vlan environment. It's a simple single VLAN default with IGMP and IGMP snooping enable with default timers. The article you shared is taking about L3 multicast. I checked the output of command and it is showing almost 39 streams at the time when it is freeze.
Userlevel 1

Userlevel 3
Do you have an igmp querier for vlan default ? If it is a single switch, do you have an ip address configured for vlan default (which will act as igmp querier)?
Userlevel 1
Got it thanks; problem resolved after configuring the IP address on default vlan. Now one more thing, pixelation. There are few channel which is facing pixelation problem specially sports channel (fast moving). Please advise
Userlevel 6
As far as figuring out if this a switch/network problem have you confirmed the streams are good before they get to the 440? We use testing gear by IneoQuest for IPTV delivery assurance and test stream direct off feeds and then deploy smaller devices at edge to verify network is sound. From my experience pixelation is not network it is content and encoding issues where there is to much compression and you end up with moments of grainy pixelated playback. Dropped frames due to network show up as skips and freezes like you were dealing with in the beginning ... Good hunting with your efforts.
Userlevel 6
EtherMAN wrote:

As far as figuring out if this a switch/network problem have you confirmed the streams are good before they get to the 440? We use testing gear by IneoQuest for IPTV delivery assurance and test stream direct off feeds and then deploy smaller devices at edge to verify network is sound. From my experience pixelation is not network it is content and encoding issues where there is to much compression and you end up with moments of grainy pixelated playback. Dropped frames due to network show up as skips and freezes like you were dealing with in the beginning ... Good hunting with your efforts.

Hi, EtherMAN!

I'm not actually agree with you.
Problems with igmp can be cause for pixelation too.
Burst and drops can lead to the pixelation.

Thank you!
Userlevel 6
EtherMAN wrote:

As far as figuring out if this a switch/network problem have you confirmed the streams are good before they get to the 440? We use testing gear by IneoQuest for IPTV delivery assurance and test stream direct off feeds and then deploy smaller devices at edge to verify network is sound. From my experience pixelation is not network it is content and encoding issues where there is to much compression and you end up with moments of grainy pixelated playback. Dropped frames due to network show up as skips and freezes like you were dealing with in the beginning ... Good hunting with your efforts.

True that AlexandrP but then they should see it spread across all content and not just fast moving sports content.... "There are few channel which is facing pixelation problem specially sports channel (fast moving)." IGMP and networks switches do not as a rule pick out a specific data stream to mess with unless they are asked to.
Userlevel 7
EtherMAN wrote:

As far as figuring out if this a switch/network problem have you confirmed the streams are good before they get to the 440? We use testing gear by IneoQuest for IPTV delivery assurance and test stream direct off feeds and then deploy smaller devices at edge to verify network is sound. From my experience pixelation is not network it is content and encoding issues where there is to much compression and you end up with moments of grainy pixelated playback. Dropped frames due to network show up as skips and freezes like you were dealing with in the beginning ... Good hunting with your efforts.

Are we talking MPEG2 or MPEG4? Packet loss will give different visual artifacts, being worse with MPEG4. Usually with MPEG4, you go back to the base frame (is that an I frame? not sure anymore of the correct terminology :)), so visualy you have a lot of pixelisation, then an old frame and your back to the stream at the next I-frame.

Are the fast moving images of sport channel producing a higher bitrate stream? (are you re-encoding the streams?).

Check your buffer usage, and eventually try to adapt it on the required port if needed.
Userlevel 1
Many thanks everyone; client is satisfied with the performance as compared to Cisco 🙂. I will surely get back if any thing new heard from them
Userlevel 6
Waqas Naeem wrote:

Many thanks everyone; client is satisfied with the performance as compared to Cisco 🙂. I will surely get back if any thing new heard from them

Welcome to the Hub Waqas. Really glad you joined us.

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