[asterisk-users] make calls from DID

[A J Stiles]

On Thursday 26 May 2011, virendra bhati wrote:
> How to make outgoing calls from DID and what is theway to get incoming
> calls from DID.

First of all, get your dialplan and zaptel configuration working to the extent 
as you can make SIP to SIP calls between extensions, and you can make 
outgoing calls on the PSTN by means of Zaptel or DAHDI -- even if they show 
up anonymous at first.


Second, in the dialplan context where incoming calls arrive  (it's specified 
in zapata.conf)  the "extension" is the number that was dialled by the 
subscriber on the other end; possibly with the leading zero stripped from the 
STD code, or possibly with the whole STD code stripped, depending on the 
telco.  So try something like this for a test  (assuming the context is 
called "from-pstn"):

[from-pstn]
exten => _.,1,NoOp(${EXTEN})
exten => _.,2,Hangup()

Call one of your allocated inbound numbers from a mobile, and watch the 
console; the NoOp() will display the dialled number  (it's still considered 
to be an "extension" even though it's a number on the PSTN)  as Asterisk sees 
it modified by the telco.


Now make a new from-pstn context which maps the extensions on inbound calls to 
your internal extensions.  For example, if the telco sends "680661"  (no STD 
code, just local part)  for the number you want to map to internal extension 
261, then you want something like

[from-pstn]
exten => 680661,1,Dial(SIP/261)
exten => 680661,2,Hangup()

Obviously if the STD code is included by the telco, you will need to include 
this in the extension number.  Reload your dialplan, dial your STD code 
followed by 680661 from your mobile, and extension 261 should ring.


That's the incoming side sorted  :)  Now you also want each internal 
extension, when it makes an outgoing call, to set the caller ID to its DDI 
number.


In the context through which extension 261 dials out  (specified in sip.conf),  
you need to set your callerID to the DDI number  (which may need the STD code 
prepending even if the telco strip it -- be prepared to experiment a little.  
No decent telco will let you present a number that you haven't the right to, 
so calls will appear anonymous if you get this wrong).  I'm assuming 
variables STD and TRUNK are already defined earlier in your dialplan.

[ext261-outgoing]
exten => _0X.,1,Set(CALLERPRES()=allowed)
exten => _0X.,2,Set(CALLERID(num)=${STD}680661)
exten => _0X.,3,Dial(${TRUNK}/${EXTEN})
exten => _0X.,4,Hangup()


Spotted the problem with this yet?  Each extension will needs its own context 
for outgoing calls, which will rapidly become unworkable.

To avoid this situation, you just need to make sure there is an obvious 
mathematical relationship between internal extensions and external numbers.  
If 6806XX on the outside is equivalent to 2XX on the inside, then you could 
try

[from-pstn]
exten => _6806XX,1,Set(dest=2${EXTEN:-2)
exten => _6806XX,2,Dial(SIP/${dest})
exten => _6806XX,3,Hangup()

1:  Set "dest" to "2" followed by the last 2 digits of the dialled extension
2:  Dial "dest"
3:  Hangup

[outgoing]
exten => _0X.,1,Set(ident=6806${CALLERID(num):-2}
exten => _0X.,2,Set(CALLERPRES()=allowed)
exten => _0X.,3,Set(CALLERID(num)=${STD}${ident})
exten => _0X.,4,Dial(${TRUNK}/${EXTEN})
exten => _0X.,5,Hangup()

1:  set "ident" to "6806" followed by the last 2 digits of the caller ID of 
the originating extension
2, 3:  Set the displayed caller ID to the value of "STD" defined easrlier in 
the dialplan followed by the value of "ident" just calculated
4:  Call the outside-world number
5:  Hangup

It will probably take some experimentation to get right; but once you manage 
it, it really will Just Work Forever.  And once you have everything working 
correctly at the most basic level, *then* is the time to think about adding 
refinements.  As restorers of old colour tellies like to say: First get it 
right in black and white.  The same principle applies here.


And be sure to save copies of all your *actually working* dialplans, peppered 
with comments, as you go along.  (Sometimes I miss the automatic versioning 
filesystem of VAX/VMS .....)

-- 
AJS

Answers come *after* questions.