[Asterisk-Users] Paging/Intercom (was: OT - SIP Auto-Answer for Cisco 7940/7960!!)

[John Todd]

>  > On the analog front, since we're talking about paging or intercom: it
>>  has been mentioned that the Sayson ADSI phones (Aastra?) are
>>  integrated with an Altigen PBX system, that the phones can support
>>  paging.  See the link below.
>>
>>  http://www.sayson.com/product/Altigen.htm
>>
>>  If this could be combined with a Cisco ATA-186 or similar product,
>>  would it not be possible to have paging via SIP delivery?  I have not
>>  put anything other than the most basic thought into this, and I don't
>>  know exactly how they support ADSI-based paging, but has anyone
>>  worked on this?  I mentioned it via IRC and someone said they took a
>>  half-hearted stab at it, but it didn't sound like it had been
>>  explored in depth.  That is a major feature issue that most business
>>  customers are looking for, and it would be great to have some
>>  combination of devices that offered paging or intercom.
>>
>  > JT
>
>I have just put in some analog phones that offer intercom/paging and work
>rather well so far.
>
>They are Smartalk phones. (NOT ADSI)  The guys there have been real good
>about helping me get buttons programmed exactly the way I want them etc.
>These phones also allow for staion monitoring and have an attendant console.
>These phones use 4-pair wiring so 3 lines + power pair.  The power pair is
>also responsible for the intercom/paging/station monitoring.  With the right
>wiring it might work with an ata device.  Just a thought.
>
>http://smartalk.ca/nrgover.htm
>
>Andy

Looks useful, but requires essentially a second line to work as a 
pager or intercom.  Not necessarily a bad thing, but as an an example 
it would require a whole ATA-186 to just get one line and the 
"paging" feature working, plus perhaps some additional wiring to work 
that all into the power pair.  Also, it is unclear if that will work 
at all, since there is no documentation on their website about how, 
exactly, the "pager" or "intercom" features work.  It's completely 
undiscussed at the nuts-and-bolts level (though they tell you what 
buttons to push.)

I'm still waiting for a _good_ implementation of paging and intercom 
for use with SIP.  Let's define "good" for an intercom/pager (i/p):

Mandatory:
   - i/p can be activated while user is off hook (speakerphone or handset)
   - deskset has local option for refusal of i/p while off-hook
   - deskset has local option for refusal of i/p completely
   - deskset has separate volume controls for i/p messages
   - deskset plays announcement beep before intercom auto-answer
   - password authenticated SIP messages for auto-answer i/p (i.e.: no 
spam calls get through that aren't authenticated by a chosen upstream 
proxy server)

optional:
   - pager announcement audio via multicast (very, very optional)

JT