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New Member

PPP multilink, big problem


I have two routers, one 7206VXR and one 3661.

They are interconected by 6 E1 links.

I configured ppp multilink, and use static routes, at this moment everything is OK.

I have in 3661´s Lan two video source, one Mpeg1 at 2Mb, and another Mpeg2 at 4 Mb, transmiting both on UDP (multicast traffic) whith different Destination IP and Port.

I configured pim sparse-mode and everything still OK.

In the central Site when I subscribe a multicast group to see the video the video looks horrible, with multiples "artefacts" (loss packet). I tried some things, like make a tunnel, virtual templates, and same result.

I tried to subscribe just 2Mb video and leave the multilink limit to 2 E1(4 Mb), the video looks perfect, but when i Begin to add phisical interfaces to multilink group, the video decrease quality. I think this is for the way that multilink works with packets, there are many,many, reorodered on sh ppp multilink command.

When I trie with the 4Mb video the results are the same, i tried too leave just three phisical interfaces on multilink, but the video quality is very poor.

Any comments will be apreciated.

Thanks in advance.

How can i do to increase video performance ?

New Member

Re: PPP multilink, big problem

Nobody have any idea ?

I dont explain myself right ?

Need more data ?

Help me ! please !!!


Re: PPP multilink, big problem


can u chck the reliability of other E1s? may be due to which u r getting the packet drops once u bundle them up.


New Member

Re: PPP multilink, big problem

Thanks !

I saw statistics on the physical port, but they are OK, no drops, no flush, in the serial interfaces nothing wrong aparently.

But in the interface multilink:

Router-CMC-MA#sh ppp multilink inte multilink 1

Multilink1, bundle name is router-es1-ma

Bundle up for 1d11h, 1/255 load

Receive buffer limit 73152 bytes, frag timeout 1000 ms

132/0 fragments/bytes in reassembly list

1573 lost fragments, 473819 reordered

25/627142 discarded fragments/bytes, 26 lost received

0x167425 received sequence, 0x130F5E sent sequence

Member links: 6 active, 0 inactive (max not set, min not set)

Se1/1, since 1d11h

Se1/3, since 21:23:57

Se2/1, since 1d11h

Se1/0, since 1d11h

Se1/2, since 21:24:05

Se2/0, since 1d11h

Can you see something here to help ?

Thanks again !


Re: PPP multilink, big problem

MLPPP is CPU intensive. What's the router utilization look like as you add circuits? Also, the data can only flow as fast as the slowest circuit because of the round robin and fragmentation. Test response time on each circuit and see if one is a lot slower than the others.

New Member

Re: PPP multilink, big problem

Can you paste your configs...

Do you have CEF running on your routers.


Re: PPP multilink, big problem

Have you tried to interleave your packets with PPP multilink interleave ?

int virtual template 1

encap ppp

ppp multilink interleave

int Se1/1

ppp multilink group-member 1


ppp multilink group-member 1

int Se2/1

ppp multilink group-member 1

int Se1/0

ppp multilink group-member 1

int Se1/2

ppp multilink group-member 1

int Se2/0

ppp multilink group-member 1

This will interleave video with the larger data packets