[OpenSER-Users] The Via Header of CANCEL Message

[Bogdan-Andrei Iancu]

Hi Fangyu ,

My opinion is that the RFC3665 does not cover the stateless part.

OpenSER can be both a stateless ans stateful proxy, it is just a matter 
of configuration (what functions are you using). You can get pure 
stateless or stateful cfg, or a mixed one, depending of you.

If you use the TM function for relaying and replying you will get a pure 
stateful proxy. For stateless functions, see the forward() or sl module.

regards,
bogdan

fancy wrote:
> Hi Bogdan:
>
> RFC3665 didn't mention any stateful or stateless 
> within all the document.
> So I think it is just not covering it.
>
> By the way, is openser a stateless proxy server?
> I think it is a stateful proxy server!
> Can I config it to be a pure stateless or stateful proxy server?
>
> Thank you.
>
> Best Regards,
> Fangyu Ling
>
>
>   
>> 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 
>> 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:
>>>>         
> Sorry it's RFC 3261 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:
>>>>         
> Sorry it's RFC 3261 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:
>>>>         
> Sorry it's RFC 3261 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
>>>>>
>>>>>           
>
>