Voice Quality Issues and RTP Header Compression

bruce.l.williams · ‎09-15-2005

Has anyone had problems with RTP Header Compression. A customer is running Voice over IP over our MPLS VPN. They are experiencing packet loss and the interfaces are incrementing flushes and output drops. I have run SAA and seen some SAA packets dropped also. The circuits tested clean so I am beginning to suspected RTP Header Compression. It is enabled on all interfaces and it causes the router to process switch so I am thinking this is creating delays and leads to the flushes and the drops.

Am I on the right path?

Has anyone else seen a problem with RTP Header Compression?

Bruce

teodorgeorgiev · ‎09-19-2005

As far as I remember, Cisco does not recommend running cRTP on links > 768Kbps. As for me, I can say that after 1.2Mbps you can face some peformance issues.

bruce.l.williams · ‎09-19-2005

I agree. We had cRTP on our T1 interfaces and also on a 30Mbs HSSI interface. I did not want to run cRTP on those links but we had a vendor that insisted. Voice packets were being dropped. There was extensive delay and jitter. We removed cRTP and everything is fine now.

spremkumar · ‎09-19-2005

hi

do confirm whether you have got any qos policies defined for different traffic patterns or not ?

and also about the traffic patterns being pumped on that link like the utilisation and the applications being passed on..

regds