[asterisk-users] Looking for wisdom - One Asterisk system - Multi-incoming trunks

[Myles Wakeham]

I'm pretty new to this whole Asterisk system & VoIP thing, but being a 
programmer by trade the complexity didn't scare me off (at least not yet)...

I have setup an Asterisk system for my home & home office.  My wife & I 
run two separate businesses from home, and we have a general family home 
phone line as well.  The cost of all these lines with analog carriers 
was getting ridiculous, so I'm moving over to a SIP carrier.  I created 
one account for a single phone number with a SIP carrier (BroadVoice) 
and have it working well with my Asterisk system and one SIP phone here 
as a test.  I have IPCop as my Firewall/IDS system and all the SIP/NAT 
routing stuff is working fine (now).

I started the process today to get our other phone numbers moved over to 
BroadVoice.  I checked with them regarding how this is setup and they 
said that what I was doing was ok, but I thought getting some 'peer 
review' on this wouldn't be such a bad idea so I welcome any comments, 
etc. on this.

My approach is to have one trunk provided by the SIP provider.  All 
numbers are allocated to that trunk (BroadVoice let me do that when I 
setup the number transfer).  Asterisk receives an incoming call on that 
trunk and determines the calling number that it was requesting (not sure 
  how to get this, but Broadvoice assured me I could).  Anyway after 
determining what the call was destined for, I then route the call to the 
  appropriate context in the extensions to handle it.

I'm fine with setting up all the logic, flow, etc. for the calls.

But here's where I'm not sure what to do.  I'm getting 4 line 
Grandstream phones for my office and my wife's office.  And an ATA 
adapter for the general home line.  The home line will always call out 
using the home phone number.  The office numbers, however, should change 
their caller ID and caller name based on which extension is pressed on 
the phone for the outgoing call.  I can see how to do this with the 
Grandstream SIP phones, and have this working ok for my test phone line.

Broadvoice, however, won't let me change the outgoing caller ID. 
Apparently they have to do this on a trunk by trunk basis.  So if I want 
to have an outgoing call go through line 1 (let's say its ACME Inc), I 
want it to show 'XXX-XXX-XXXX Acme Inc' for the Caller ID.  But if the 
call is being sent through line 2 (let's say its SMITH PROPERTY) I want 
it to show 'YYY-YYY-YYYY Smith Property' for the Caller ID.  It looks 
like in order to do that, I need to purchase separate trunks for each of 
the outgoing lines.

Does this sound right?  Should I have purchased all separate trunks up 
front and then have the phone number transfer associated with the trunk 
for it?  Or is this only something that will affect outgoing calls, so 
its not a big deal?  And what about when the line is busy?  How is that 
handled?  I was on the phone yesterday when another call came in, and it 
came in, jumped to a different extension and then eventually went to 
voice mail as I didn't answer it.  Will my plan to use one trunk for all 
incoming lines make sense here, or am I likely to get all of this mixed 
up with calls coming in for one business and being routed to the wrong 
place?

Any suggestions, thoughts or critique would be greatly appreciated.

Thank you wise Asterisk gurus!

Myles
-- 
=======================
Myles Wakeham
Director of Engineering
Tech Solutions USA, Inc.
Scottsdale, Arizona  USA
http://www.techsolusa.com
Phone +1-480-451-7440