[OpenSER-Users] The Via Header of CANCEL Message

Klaus Darilion klaus.mailinglists at pernau.at
Wed Jul 4 18:11:34 CEST 2007



Bogdan-Andrei Iancu wrote:
> Klaus,
> 
> you are right! in stateful mode, the CANCEL is routed hop by hop but not 
> constructed (at least not by openser) - that is something I have on the 
> todo list and really want to have in 1.3

if you add this maybe it should be configurable to activate the old 
behavior - in case of clients having problems.

regards
klaus

> 
> regards,
> bogdan
> 
> Klaus Darilion wrote:
>>
>>
>> Bogdan-Andrei Iancu wrote:
>>> Klaus,
>>>
>>> CANCEL is hop-by-hop only in stateful processing and in this case, 
>>> yes, it has only on VIA. But if you have stateless processing, CANCEL is 
>>
>>      ^^should
>>
>> but in fact, also when using tm the CANCEL has 2 Via headers:
>>
>> U 88.198.53.113:6060 -> 83.136.32.160:5060
>> CANCEL sip:klaus.darilion at nic.at43.at SIP/2.0.
>> Max-Forwards: 10.
>> Record-Route: <sip:88.198.53.113:6060;lr=on;ftag=d421fe7e>.
>> Via: SIP/2.0/UDP 88.198.53.113:6060;branch=z9hG4bKdd22.f7f861b6.0.
>> Via: SIP/2.0/UDP 
>> 10.10.0.50:13946;received=83.136.33.3;branch=z9hG4bK-d87543-2e40397a3e383c6b-1--d87543-;rport=13946. 
>>
>> To: ...
>> ...
>>
>>
>>
>> regards
>> klaus
>>
>>> end-2-end and it will have multiple VIAs...
>>>
>>> Does 3665 obsoletes stateless SIP or it is just not covering it???
>>>
>>> regards,
>>> bogdan
>>>
>>> Klaus Darilion wrote:
>>>> Looks like it is defined clearly and openser is not 100% standard 
>>>> conform.
>>>>
>>>> regards
>>>> klaus
>>>>
>>>> fancy wrote:
>>>>  
>>>>> Hi Klaus:
>>>>> RFC 3665 page 54 line 4:
>>>>>    A CANCEL constructed by a
>>>>>    client MUST have only a single Via header field value matching the
>>>>>    top Via value in the request being cancelled.
>>>>>
>>>>> and RFC 3665 at page 53:
>>>>>    CANCEL is referred to as a "hop-by-hop" request, since it is
>>>>>    responded to at each stateful proxy hop.
>>>>>
>>>>> and RFC 3665 at page 21:
>>>>>    Client: A client is any network element that sends SIP requests
>>>>>          and receives SIP responses.  Clients may or may not interact
>>>>>          directly with a human user.  User agent clients and 
>>>>> proxies are
>>>>>          clients.
>>>>>
>>>>> So, for my opinion, the role of proxy in this case of RFC 3665 
>>>>> section 3.8 is a client when it sends CANCEL message to Bob.
>>>>>
>>>>> If I misunderstand any RFC meanings, please correct me.
>>>>> Thank you very much.
>>>>>
>>>>> Best Regards,
>>>>> Fangyu Ling
>>>>>
>>>>>
>>>>>  
>>>>>> fancy wrote:
>>>>>>    
>>>>>>> According to RFC 3665 section 3.8 and RFC 3261 section 9,
>>>>>>> there is only one via header in CANCEL message
>>>>>>> (message F11, F13 at page 72 of RFC 3665).
>>>>>>>         
>>>>>> Hi!
>>>>>>
>>>>>> I could find it in RFC 3665, but not in 3261. Where exactly in RFC 
>>>>>> 3261
>>>>>> is mentioned that the CANCEL has only 1 Via header?
>>>>>>
>>>>>> Further, the example has only one Via header - but I could not 
>>>>>> find any
>>>>>> definition if this is a MUST or not.
>>>>>>
>>>>>>    
>>>>>>> How can I remove the 2nd via header?
>>>>>>>         
>>>>>> You would have to modify tm module and change the code which 
>>>>>> generates
>>>>>> the CANCEL message.
>>>>>>
>>>>>> regards
>>>>>> klaus
>>>>>>
>>>>>>       
>>>>
>>>> _______________________________________________
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>>>> http://openser.org/cgi-bin/mailman/listinfo/users
>>>>
>>>>   
>>>
>>
> 




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