[OpenSIPS-Users] REFER - Transferring Best Practice.

[Anca Vamanu]

Hi David,

With the b2bua in opensips you can handle REFER at server. The scenario 
to be used in this case can be found here:
  http://www.opensips.org/Resources/B2buaTutorial#toc15.

Regards,

-- 
Anca Vamanu
www.voice-system.ro



On 09/15/2010 07:23 PM, David J. wrote:
>    Adrian,
>
> So in that case I would need to have a PBX, such as Asterisk, or
> FreeSWITCH to handle this case, which would mean the PBX has to be in
> the call path the entire time?
>
> Thanks.
>
>
>
> On 9/15/10 12:17 PM, Adrian Georgescu wrote:
>    
>> Call transfer using SIP require cooperation between the 3 end-points involved.
>>
>> On the public internet, which is probably why you want to use OpenSIPS, this does not work primarily because of accounting reasons. You can configure the SIP proxy to route the Refer and Notify alright but as an end-point you will not succeed at instructing for instance  a remote PSTN gateway to transfer the call to some other end-point because you have no trust relationship with it and nobody can be billed for this new call leg.
>>
>> Handling the routing of REFER in OpenSIPS is trivial but it will not solve your problem.
>>
>> The only way you can make transfer work reliably is behind the same PBX.
>>
>> Adrian
>>
>>
>> On Sep 15, 2010, at 6:02 PM, David J. wrote:
>>
>>      
>>>    Seems like when I try to transfer a call from one user to the next, it
>>> does not do anything, so I am guessing we have to handle the REFER message?
>>>
>>> What is the best practice for handling REFER messages?
>>>
>>> Thanks.
>>>