[SIPForum-discussion] Use case for changing contact with re-invite

[Stephen James]

If the SBC is using static IP for redundancy and fails over to the other IP or blade or server it will need to update with a re-INVITE. 

Sent from my iPhone

On May 29, 2012, at 23:05, seshagiri <seshgirik at gmail.com> wrote:

> Hi
> 
> In sip what is the use case for the scenario  to change the contact ip  with re-invite after the session establishes ?
> 
> The scenario is 
> 
> A calls B through SBC which is B2BUA.
> After session establishes A sends re-invite to SBC with new-contact and receives 200 OK.
> This re-invite is not relayed to UA B.
> 
> Now B sends BYE , SBC receives and send it to the new contact of A and receives 200 OK.
> This scenario is working fine , but  what is the use case for this ?
> i could not able to undrestand it.
> 
> A -----INVITE---------->SBC -------INVITE------------>B
> A< -----200--------------SBC< ------------200------------B
> A -----ACK----------->-SBC ----------ACK------------>B
> A -----re-INVITE(New contact)--------->-SBC
> 
> A< -------200-----------SBC
> A -----ACK------------->SBC
> A <-----BYE(to new contact of A)----------SBC< -------BYE------------B
> 
> 
> In real-time scenario what is the use of changing the contact with re-invite ?
> i think if UA using DHCP and is going to change IP after session establishment , in this case it might send re-invite with new contact , is this correct ?
> 
> Pl share your views.
> 
> 
> Regards
> Sesh
> _______________________________________________
> 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