[Serusers] pa module does not always send OK before NOTIFY

[Jamey Hicks]

JAY ALLISON wrote:

> I have searched the archive for an answer to this question, and I did 
> not find it.  If I missed, I apologize.  Please point me in the right 
> direction.
>  
> I am having a problem with the pa module of ser (0.8.12).  Using 
> ethereal, I see that in response to a SUBSCRIBE, ser will sometimes 
> send an OK and then a NOTIFY.  However, other times ser sends the 
> NOTIFY and then the OK.  For a single UA sending multiple SUBSCRIBE's 
> to ser, about half of the OK's are sent first and about half of the 
> NOTIFY's are sent first.
>  
> This is a problem because I am running the UA behind a SIP-aware 
> firewall which expects the OK first.  If the OK is not received, the 
> NOTIFY will not be allowed back through the firewall.
>  
> Looking at RFC 3265, 3.1.4.1:
> "This SUBSCRIBE request will be confirmed with a final response.  
> 200-class responses indicate that the subscription has been accepted, 
> and that a NOTIFY will be sent immediately."
>  
> Looking at RFC 3265, 3.1.6.2:
> "Upon successfully accepting or refreshing a subscription, notifiers 
> MUST send a NOTIFY message immediately to communicate the current 
> resource state to the subscriber.  This NOTIFY message is sent on the 
> same dialog as created by the SUBSCRIBE response.
> <snip>  
> Note that a NOTIFY message is always sent immediately after any 
> 200-class response to a SUBSCRIBE request, regardless of whether the 
> subscription has already been authorized."
>
> My interpretation is that the RFC requires the OK to be sent first.  
> Is that a valid interpretation?
>  
> Is there an easy fix for this (perhaps in ser.cfg) or will this 
> require a code change?

I changed the behavior of this in the CVS version in January.  Before 
that, it was sending the notify before generating the response.  
Currently, it only sends NOTIFY messages from the periodic call to 
timer_presentity().  I guess the timer could get called before the 
response is sent.  I'll see if I can delay setting the flag indicating 
that a notify should be sent until after the response is actually sent.

Jamey