[SIPForum-discussion] When user not responding to the call

[vlauwers at drtech.fr]

Hello,

At UAC side, if no response (provisional or final) is received within
500ms, the INVITE request is retransmitted. The retransmission intervall
is doubled until a response is received, with a maximum of 7
retransmission attempts.

At UAS side, UAS expects receiving a ACK immediately following the
transmitted 200 OK. If no ACK is received, the UAS retransmitts the 200 OK
500 ms later.

But your scenario does not correspond to any of these two cases. UAS
transmits the 180 Ringing, but no 200 OK, meaning the phone is ringing,
but no one answers. In such case, application servers / softswitch are
usually configured to reroute calls to the callee's voice mail after a
certain ringing time.

Regards,

> Hi All,
>
> I have doubt regarding the call scenario when Caller(UA2) is not
> responding
> to the call , so what would be the possible steps to be taken care?
>
> e. g.
>                      INVITE
> UA1---------------------------------------> UA2
>                       TRYING
> UA1 <------------------------------------- UA2
>                         RINGING
> UA1 <-------------------------------------- UA2
>                             ---
>                             ---
>                             ---
>                    No Response ?
> UA1 <--------------------------------------UA2
>
> Please Guide
> --
> Regards,
> Sachin Parnami
> _______________________________________________
> This is the SIP Forum discussion mailing list
> TO UNSUBSCRIBE, or edit your delivery options, please visit
> http://sipforum.org/mailman/listinfo/discussion
> Post to the list at discussion at sipforum.org
>