routers forward multicast video packets so slowly

[amir_rashidy67]

hey guys
I have a problem with multicast, here is the senario.
I have a video Server that sends streams in multicast to its clients. the clients in same subnet with server don't have any problem and receives streams clear but the clients that are not in same subnet which means their packets must cross the routers  receive the streams so slow and not clear.
all of my routers are 3845 but my RP is 3945.
I changed all routers IOS but it doesn't fix the problem.
I enabled cef and MFIB on all router and on 3845 routers configurations are so simple, just setting  sparse-dense-mode and MFIB in interfaces and rp address for global.
so I will thank anybody who help me for rest of my life because I kinda thinking about killing myself because of this problem.....it just doesn't make sense
and someone in other forum told me its MTU Issues, but how can i fix this

thanks

[lonmc1977]

Try creating GRE tunnels between a couple routers, direct MC traffic through the tunnel and see if it helps

[amir_rashidy67]

there r GRE tunnels right now....not helping

I have over 180 networks with 32 routers 50% of them r connected with GRE and IPsec tunnels over Internet. but some of them r connected directly to each other.

lets say i have just one router and 2 networks....still have the problem

but the thing is in layer 2 I mean in clients in same subnet I don't have any problem to receive the streams it just happen in the routers when they come to layer 3 forwarding  

[Joseph W. Doherty]

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Posting

Well at least your 2nd post mentions tunnels and IPSec.  For video, you may very well be having MTU issue across tunnels as video can often easily fill a packet.

Since the traffic is multicast, the only way I can see you avoiding fragmentation is reducing the MTU on the source video device.

[amir_rashidy67]

i reduced the MTU yesterday to 1000 and 1400 but still same problem....it shows the video but its slow motion.....(its default is 1500) 

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

What's your CPU loading look like on the routers?

[amir_rashidy67]

its around 20% ....its not my cpu issues....i have Ipsec tunnels, sometimes they make the routers some extra process and they get to even 90%

i just test something, I used that app which my source of multicast traffic in a lab environment and i had the same problem

multicast traffic i ok in layer 2 before they pass the router(I can see the stream clear) but when it pass the first router and it route the traffic the problem occurs(i can see the video stream but its slow motion) 

thank you for your help