[SIPForum-discussion] RPID in ACK

[Raj Jain]

On Tue, Jun 17, 2008 at 6:23 PM, Raghul Prasanna <raghul82 at yahoo.co.uk> wrote:
>  I have a scenario were calls to Verizon are getting rejected. When I looked
> at the ethereal I found that we are sending ACK to 200 OK from Verizon. But
> they keep sending us 200 OK and we respond to it everytime and finaly they
> time out.
>
>
>
>  When I checked with Verizon they said that we dont send RPID in ACK. I have
> never come across this scenario were RPID needs to be sent in ACK. I thought
> its sent in Invite message which we do.
>
>
>
>  Does anyone know if there is any spec which states that RPID shd be sent in
> ACK?

RPID is a long expired internet-draft. Here is a link to the draft:
http://tools.ietf.org/id/draft-ietf-sip-privacy-04.txt. The table in
section 6 in this shows that the header is not defined for the ACK
method. I doubt that RPID missing in the ACK is the reason why you've
200/ACK retransmissions. Typically, you have these retransmission
problems due to messages not reaching the destination or
transaction/dialog mismatching.

--
Raj Jain