[Asterisk-Users] SIP Subscriptions

[Douglas Garstang]

             >-----Original Message----- 
             >From: C F [mailto:shmaltz at gmail.com] 
             >Sent: Tue 12/20/2005 9:58 PM 
             >To: Asterisk Users Mailing List - Non-Commercial Discussion 
             >Cc:  
             >Subject: Re: Re: [Asterisk-Users] SIP Subscriptions
             >
             >Lets get this clear once and for all, you are a Fuc*ing retard, and
             >his will be the last (I hope) you will hear from me in this post.
             >>And now to the post.

	>
	>On 12/20/05, Douglas Garstang <dgarstang at oneeighty.com> wrote:
	>> Well, I know I will be attacked for saying this, as cursed are those who say anything bad about Asterisk, but for an application that is 'enterprise-grade' as Digium tourts, it has several flaws that IMHO disqualify it as 'enterprise-grade'. I mean, >>really, c'mon... think about it... an application that doesn't support the use of a database for common location/registration information is hardly 'enterprise-grade'. Just off the top of my head,
	>
	>Like any of the other systems do, lets check which ones? Avaya
	>Definity? Panasonic?
	>Why is AstDB not a database? You can query it using asterisk -rx, and
	>then use your own functions based on the results. In an enterprise
	>grade installation one doesn't want another point of failure like a
	>database. A database is only usefull if you want to be able to have
	>the *same* database for every system, whicn in most asterisk system
	>this is *not* needed. At the most you want to share the DP which can
	>be done in other ways.
	 
	Your not understanding the problem with a common location database. If you have multiple Asterisk boxes, phones may register with any of these Asterisk boxes in a redundant configuration. When that happens and phoneA is registered to Asterisk System 1, it will not be able to find phoneB registered with Asterisk System 2. Asterisk has no way to share this registration information. Each Asterisk box has its own astdb file, but it's not shared and provides no visibility as to the location of phones registered on other Asterisk systems.
	 
	Asterisk does not provide a mechanism to activate a command upon registration from a SIP phone. That might have been one way to do it, ie 'replicate' somehow the registration to all the other Asterisk systems. Realtime does not support the use of multiple Asterisk boxes accessing the same SIP peers data in the database. It may work sometimes, and not others and therefore it can't be relied upon. DUNDi _might_ do it, but documentation on that is scarce, and the docs I have found are wrong (ie they tell you to use auth=rsa in sip.conf where it's not supported). I've had other people in my department scouring over the scant DUNDi docs for days trying to make heads of tails of it. I'm at a complete loss as to why Digium can't release some docs on it. It's their protocol after all.
	 
	Why is the same location database not needed for all Asterisk systems? If you want to have them in a redundant fashion, ANY Asterisk system should be able to route calls between any two phones. This requires a central location database (either a real one or a file). 
	 
	Yes, the dial plan can be shared, but I am yet to see a way in which the LOCATION (ie port, ip address etc),that is availability, of a phone can be shared between Asterisk systems.
	 
	
	
	>other disqualifiers would be:
	>>
	>> 1. SIP subscriptions are stored in memory and cleared when you do a 'reload'. So, if you make any configuration changes and 'reload' you lose all your BLF lights. People take this stuff for granted and expect it to work.
	>
	>I have installed more Asterisk systems than you (yes I'm sure of it,
	>you are too big of a moron), not ONE of those systems make use of the
	>hint feature (although I'm looking at it currently), and my clients
	>are very happy (I use FOP). Tell me how this disqualifies this system
	>to for enterprise grade, as I have installed in enterprise grade
	>installs.
	I don't understand how you can say that. BLF is a standard part of any antiquated PBX system. It's been around forever. People take this functionality for granted and just expect it to be able to work. Why would they want to switch to a VOIP solution if they have to give up functionality??? It's a requirement for our production deployment.

	
	>>
	>> 2. No common SIP registration information. Not even using realtime with SIP users, which doesn't work, there's no way outside this to share location info between more than one (ie 'enterprise-grade') Asterisk systems.
	>>
	>
	>For this #2 question:
	>A. Why would this be needed? you could use switch to share the DP, or
	>you could simply have asteriskB just dial extenx on asteriskA which
	>asteriskA will then dial that SIP
	>B. You could share it using asterisk -rx "sip show peers" or the like.
	>C. You could use Avaya.
	Because the phones may register with ANY Asterisk system. If you force a phone to register with one Asterisk box, it isn't exactly redundant now is it. If you configure the phones to use a specific Asterisk system as primary and another as secondary, it doesn't scale very well. As you add Asterisk boxes, you increase the complexity greatly. I don't believe the switch => command will provide any location data. It doesn't tell you if the user is registered on that other system or not, only that the othe system has a dial plan entry. If the phone isn't registered with that system, you get a failure. Considering that Asterisk doesn't seem to handle Dial() failures very well, I don't believe this could work.

	 

	>> 3. The 'Dial' application seem to have very limited ability to be able to determine what SIP response it gets back from a peer. "Not Found", "Busy", "Moved" etc. I know Asterisk isn't a SIP proxy, but without the ability to check the SIP message >status in a dial, it makes redundancy very very difficult. Redundancy is normally an important part of 'enterprise-grade'. Without this, how do you get upstream redundancy? I have something working right now, but it isn't pretty!
	>
	>There are lots of DP magic in this area that can tell you precisely
	>whats going on. It's just your inability to RTFM that makes this a
	>point, I mean realy how can you possibly know enough about Asterisk in
	>just 14 days????????????? Your ignorants does NOT imply anything about
	>asterisk.
	I never said I'd only been working with Asterisk for 14 days. It's been about 2 months. I've been scouring over every conceivable piece of information I have been able to find, and I will tell you that docs on Asterisk are light. Accurate ones are even lighter. I'm yet to see any 'DP magic', or see any intelligent replies on this list to questions I have specifically asked about that. 
	
	>>
	>> 4. DNS SRV lookups aren't implemented properly. Another important part of redundancy and 'enterprise-grade' software.
	>
	>Work in progress, but not with this atitude, for the mean while use Avaya.
	Yay.

	
	>>
	>> Before you all go ripping my head off and defecating down my neck for saying anything bad about Asterisk (well CF can, I expect that), this is just my opinion based on real world frustrations with Asterisk. These are intended to be >constructive criticisms.
	>
	>You got it all wrong, this is not aimed at you, but it's all aimed at
	>your local community for not putting you into an institution yet. We
	>dont' care about you and Asterisk, many of us are using it in
	>enterprise-grade installs, *YOUR* inability to do so doesn't mean that
	>asterisk has failed. If you want answers ask, dont bash.
	>BTW, you are *NOT* anyones real world example with Asterisk.
	I can point out numerous ocassions where I have asked questions, and not bashed. 

	>
	>>
	> Maybe some from Digium will read this email and it will make a 0.001% contribution towards some of these things being fixed. Oh, and no... I can't switch to another solution. The decision was made above my head to go with Asterisk. It's my job to make it do all that 'enterprise-grade' stuff.
	
	Oh, I love this last line, does that mean that they will fire you from
	this asterisk job? I'm looking forward to that.
	
	>
	> Doug.
	>
	>
	>         -----Original Message-----
	>         From: pdhales at optusnet.com.au [mailto:pdhales at optusnet.com.au]
	>         Sent: Tue 12/20/2005 8:02 PM
	>         To: Asterisk Users Mailing List - Non-Commercial Discussion
	>         Cc:
	>         Subject: Re: Re: [Asterisk-Users] SIP Subscriptions
	>
	>
	>
	>         > C F <shmaltz at gmail.com> wrote:
	>         >
	>         > On 12/20/05, Douglas Garstang <dgarstang at oneeighty.com> wrote:
	>         > > Digium needs people like me, if they read this list that is. They sure
	>         > don't seem to be able to make real-world functionality decisions on
	>         > their own.
	>         > >
	>         >
	>         > You are so right, how did we do without you the last few
	>         > years???????????
	>
	>         By living on baked beans and cabbage.
	>
	>         PaulH
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