[e-nsp] Packet loss/drop investigation

[Marcin Kuczera]

Youssef Ghorbal wrote:
>> Is it 10s and than it is back, or after 10s of call you loose voice in one
>> direction ?
> 
> Yeah, it's 10s and than it's back.
> The 10s audio loss happens randomly during the call, sometimes after 1
> or 2 minutes of call establishement but sometimes after 6 minutes.
> The only constant is the 10s consecutive one way audio loss.
> 
>> This could be some SIP issue, that RTP is redirected somewhere or, firewall
>> drops one way traffic because of some timeout (i.e. NAT problems).
> 
> It's H323 and not SIP.
> No firewall in the way (call and session manager are on the same IP
> segment) and the problem occurs on internal calls and external ones
> (GSM)
> Moreover, the problem does not happen with "other" access switchs (Cisco)
> 
> I suspect some RTP packet loss somehow in the path and I want to
> identify the culprit.
> 
>> Describe your case in more details.
> 
> The problem happens in this configuration
> 
> Avaya (9608) <-100Mb-> x460 stack <-10Gb-> x650 <-10Gb-> Brocade MLX
> <-1Gb-> Cisco <-> Avaya (Call/session manager)
> 
> The problem does not happen with this configuration
> 
> Avaya (9608) <-100Mb-> Cisco <-1Gb-> Brocade MLX <-1Gb-> Cisco <->
> Avaya (Call/session manager)
> 
> Same phone, same core switch and same Avaya servers. The only change
> is the Extreme stuff (x460 and x650) and maybe the 10G nics.
> 
> Thank you for your assistance.

Well, the only what I can propose is to mirror port where phone is and
dump the traffic. Than - analzye.

Marcin