Re: [reSIProcate] UA "486 Busy Here" & ACK in case of SIP-Proxy
An ACK to a failure response is handled hop by hop rather than end to
end. Look at section 17.1.1 (INVITE Client Transaction). In your demo
UA it sounds like the behavior is correct. Your demo UA will not see
the ACK message in the application since the ACK will be received by
the transaction layer of the stack.
Jason
On Mon, 7 Mar 2005 09:40:50 +0100, Clemens Fischer (VI/SEA)
<clemens.fischer@xxxxxxxxxxxx> wrote:
>
> Hi reSIProcate gurus,
>
> I've implemented a small (demo)UA and found a problem I couldn't come
> around. My problem is that if (via proxy) my UA e.g. calls itself, my UA
> will respond with 486 (busy here) and the ACK is sent towards the proxy
> (which will correctly skip the ACK). According to my knowledge the ACK sould
> be addressed directly to my UA ..
>
> UA (x.x.111.35) Proxy UA (x.x.111.35)
> | INVITE | |
> | --------------> | Invite |
> | | -------------> |
> | | 486 |
> | 486 | <------------- |
> | <-------------- | |
>
> ["is"]
>
> | ACK | |
> | --------------> | |
>
> | | 486(retrans) |
> | 486(retrans) | <------------- |
> | <-------------- | |
> etc.
>
> ["should???"]
>
>
> | ACK | |
> | -------------------------------> |
>
> I've alread scanned all threads but couldn't find any related issue(s) ...
>