[asterisk-dev] Asterisk and external SIP subscribtions

[Paul Belanger]

On Wed, Mar 19, 2014 at 9:56 AM, Olle E. Johansson <oej at edvina.net> wrote:
>
> On 19 Mar 2014, at 14:50, Paul Belanger <paul.belanger at polybeacon.com> wrote:
>
>> Greetings,
>>
>> I wanted to ask if there is any sort of design document / work started
>> on having Asterisk 13 be able to subscribe to external SIP messages
>> for the purpose of presence (device state).
>>
>> More and more we are trying to come up with a good way to have
>> Asterisk be aware of SIP subscriber presence from our proxy (kamailio)
>> and propagate that information into Asterisk. Today we are using
>> custom device state and some AMI / console scripts to do this, but its
>> a pain to maintain / deploy.
>>
>> So, what we (our company) was planning on doing was funding some
>> developer to go out and build us something on top of pjproject to
>> handle this.  Some sort of res_pjsip_foo module to handle presence
>> from Kamailio.  The question comes up which RFC is should be, but at
>> this point in time, that's a discussion point.
> I have an old design and some code for chan_sip, but the design should
> be working for chan_pjsip as well. Google for project pinana.
> I presented it at a astridevcon years ago.
> The important thing is to have a generic design so we can publish
> states of non-sip extensions too.
>
>>
>> Talking to matt, I think we want to use the res_pjsip_pubsub.c module,
>> but need to confirm. And the reason for having this email. So, is
>> anybody interested in helping us build it?  Both from a design apsect,
>> so we can get it into Asterisk and / or help find a developer to do
>> the work / funding?
>>
>> I see said module having some config file that will allow you to
>> specific your source, and the domains you which to subscribe too.
>> Then, when asterisk starts, it sets up the subscriptions and then
>> listens for the publish and stores them as local (internal) device
>> states.  I don't really care about adding publish support at this
>> point in time, simply because everything SIP related is outside
>> asterisk.
>>
>> EG:
>>
>> [example.org]
>> server = 192.168.1.1
>> users = *
>>
>> So, thoughts?  Interested in helping? Want to also fund this venture?
> Start with reviewing my design.
>
So the MVP for my concept is pretty simple, subscribe to external
source and update asterisk device states. The reason for this, like
everybody, is I have multiple asterisk boxes behind a proxy. So, if I
dial the same SIP subscriber from two different boxes, I want asterisk
to know the states.

I think this fits well with the res_pjsip_foo module design, but I
might be wrong.

And I want this to be simple, I don't want to depend on XMPP servers,
res_corsync, python scripts, etc.  That's why I asked if anybody else
seen value in this, which I think people do.

-- 
Paul Belanger | PolyBeacon, Inc.
Jabber: paul.belanger at polybeacon.com | IRC: pabelanger (Freenode)
Github: https://github.com/pabelanger | Twitter: https://twitter.com/pabelanger