[cisco-voip] Traffic Issues with 7900 Series Phones

[Pawlowski, Adam]

After much hair pulling and frustration, I wanted to ask the group here in case anyone has seen this or has any thought on what we should be looking for.

We have a number of 7900 series phones that have been exhibiting issues that appear to me to be that the phone is getting hung up on something. Some sort of frame or packet is screwing with the network chip/board or the OS which is causing it trouble. I see missed traffic, missed responses, high ICMP echo times - and phones that eventually get stuck with their ICMP echo response times being all over the board - with some report of call trouble and CMR showing crazy jitter. If I power cycle the phone that clears and it works fine for a while.

I realize these items are pretty much end of useful life, pretty much all done with software support, and are going to drop off of the compatibility matrix and probably functional support in the near future. But, while we still have a ton of them - has anyone noted any particular type of traffic that causes the 7900 series phones grief?

I don't have loss on the network, there do not seem to be any transient broadcast storms rolling by. We do see an increased amount of mDNS, IPv6 (phones are v4 only) etc, but nothing stands out as causing a particular problem. It just seems that whatever this is, is causing a memory leak or something, wherein it gets bad enough that things go to hell eventually. 

Any thoughts?

Adam P
SUNYAB