[asterisk-dev] Pedantic

[Klaus Darilion]

Olle E. Johansson wrote:
> 15 apr 2009 kl. 19.10 skrev Mark Michelson:
> 
>> David Hansen wrote:
>>> What exactly is setting pedantic useful for?  What conditions would  
>>> warrant setting this to yes?
>>>
>>> David Hansen
>>>
>> Basically, you can think of the pedantic setting as being one that  
>> is important
>> to SIP purists or those who do make use of more advanced/less used  
>> nuances of
>> the SIP protocol.
>>
>> For instance, RFC 3261 plainly spells out that the way to identify  
>> whether an
>> incoming message belongs to a specific dialog is to check the call- 
>> id, to tag,
>> and from tag. With pedantic mode disabled, all we look at is the  
>> call-id because
>> in the majority of situations, the call-id is suitable for  
>> identifying which
>> dialog the request belongs to. However, if you know that tag  
>> checking is
>> important, then it will be enabled by turning on pedantic mode.
> 
> I would say that Mark's view is a bit simplified. If you have a PBX  
> and a few local
> phones on the same LAN, we can skip some of the requirements of the SIP
> standard to make life more simple. On the other hand, in that case you  
> do have
> the processing power, so it's not a problem anyway.
> 
> If your asterisk is part of a larger infrastructure with forking SIP  
> proxys,
> and you need to interoperate with other SIP services, not just the local
> set of phones that only talks with your Asterisk, then you *have* to  
> enable
> pedantic to get things working properly.
> 
> I personally think that the pedantic mode is a strange setting that we  
> should remove. 

+1

Isn't that another reason why chan_sip should use a SIP stack ;-)

> It was the first thing I removed from pineapple (chan_sip3)  
> when I
> started that project (before it stopped).
> 
> Setting it to yes will never hurt, unless you have a very small CPU  
> (which can't handle many calls anyway). 

The chance that you will find bugs is higher as most users use 
pedantic=no and thus by setting it to yes you will discover bugs nobody 
else ever has experienced (at least that was my recent experience)

 > Setting it to "no" might be very bad
> for you.

I do not know of current Asterisk - but few years ago there was a very 
big problem with pedantic=no: Asterisk accepted in-dialog requests (with 
to-tag) even if there was no existing dialog in chan_sip. Is this still 
the case?

regards
klaus





> 
> /O
> 
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