[e-nsp] Packet loss/drop investigation

[Youssef Ghorbal]

> 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.

Youssef