[Serusers] HELP: re-INVITE Sometimes Not Processed Properly

[Klaus Darilion]

Hi Paul!

Java Rockx wrote:
> INVITE sent to PSTN gateway
> PSTN GW sends 180 Ringing
> PSTN GW sends 200 OK, which is sent to the SIP UA
> SIP UA replied with ACK, which is sent to the PSTN GW
> Time Elapses
> PSTN GW sends re-INVITE, which is sent to the SIP UA
> SIP UA replies with 200 OK, which is sent to the PSTN GW
> PSTN GW sends another re-INVITE

This is a retransmission - apparently the response needed more then 
0.5s. But the Gateway shouldn't send retransmissions, as it already 
received a 100 Trying. (Does the 100 trying really hit the gateway?)

> PSTN GW sends an ACK, which is sent to the SIP UA
> re-INVITE (received immediated before the ACK) is sent to the SIP UA

The SIP proxy shouldn't forward the INVITE as he already received the 
200 Ok. Strange things are happening.

regards,
klaus

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