[Serusers] Tags, forwarding, redirects, and picky UACs

[Alistair Cunningham]

Bogden,

You're quite correct, it's To:. I'm not thinking clearly today. It works 
- thank you very much!

Alistair Cunningham,
Integrics Ltd,
+44 (0)7870 699 479
http://integrics.com/


Bogdan-Andrei Iancu wrote:
> first, it's not about FROM tag, but TO tag...
> second, it's better to do it for all provisional responses < 180 (for 
> 183 you might mess with early media)
> third, here  it 's the  regexp:
> 
> onreply_route[1]{
>    if ( t_check_status("(1[0-7][0-9])|(180)") ) {
>        subst('/^(To:.*)\;tag=[^;[:cntrl:]]*/\1/i');
>    }
>    break;
> }
> 
> bogdan
> 
> 
> Alistair Cunningham wrote:
> 
>> Bogdan-Andrei,
>>
>> Can you please give me a hint as to how to remove the tag? I've can do 
>> something like:
>>
>> onreply_route[1] {
>>     if ( (status=~"180") ) {
>>     replace( ";tag=.*", "" );
>>     };
>> }
>>
>> but this would remove the tag from all headers. I could add "From:" 
>> into the regular expression, but this would then remove the whole From 
>> header.
>>
>> Alistair Cunningham,
>> Integrics Ltd,
>> +44 (0)7870 699 479
>> http://integrics.com/
>>
>>
>> Bogdan-Andrei Iancu wrote:
>>
>>> According to RFC 3261, the UAC *must* drop any To-tag received in a 
>>> provisional reply in favour of the To-tag advertised in the final 
>>> reply - be this it means not only to accept a final reply with a 
>>> different To-tag, but also to use it in generating sequential 
>>> messages (like ACK, re-INVITEs, etc)
>>>
>>> So you should report the problem to your UAC vendor. Meanwhile you 
>>> can do a trick in SER cfg - use a reply_route to remove the To-tag 
>>> from all provisional replies....this will make happy the UAC.
>>>
>>> bogdan
>>>
>>> Alistair Cunningham wrote:
>>>
>>>> I'm trying to implement forwarding to voicemail with a UAC that's picky
>>>> about the tags in the To: headers it receives.
>>>>
>>>> First, I tried the following:
>>>>
>>>> failure_route [1] {
>>>>     rewritehostport("192.168.1.1:5060");
>>>>     append_branch();
>>>>     t_relay();
>>>> }
>>>>
>>>> This failed because the UAC received a "180 Ringing" from the ringing
>>>> Grandstream phone via ser that contained a To: tag. After the timeout,
>>>> it received another 180 from Asterisk (the voicemail system) with a
>>>> different tag. Since it doesn't support forked INVITES, it dropped 
>>>> the call.
>>>>
>>>> Then I tried:
>>>>
>>>> failure_route [1] {
>>>>     rewritehostport("192.168.1.1:5060");
>>>>     t_reply( "302", "Moved Temporarily" );
>>>> }
>>>>
>>>> This time it receives the 180 from the phone as before. Then it 
>>>> receives
>>>> the 302. Alas, SER has ignored the tag from the phone, and created a 
>>>> new
>>>> one of it's own, so the UAC again drops the call.
>>>>
>>>> Does anyone know of a way round this? Can SER be persuaded to use a tag
>>>> it has already received? Can I strip the tag from the To: header in 
>>>> one or both of the responses? I'm willing to get my hands dirty with 
>>>> the SER source code if necessary.
>>>>
>>>
>>>
>>>
> 
> 
>