Hmm, this is turning into a regular saga now: so much so I’ve added a voip tag to these posts to help keep them together.

My original macro worked just fine when the incoming number and the dialled extension matched, but this is only true for my LAN and is not generally true when using external SIP providers as the incoming extension is very often the user id of the account. For this reason it’s very helpful to be able to pass in the destination extension number to the macro so that when the user calls 1471, the extension used to place that call will hear the correct caller id.

In this example, 123456 is the incoming extension from an external SIP provider, and 2000 is the actual extension on the LAN that the call is destined for:

[macro-dialcliexten]
exten => s,1,Set(DB(LastCallFrom/${ARG2})=${CALLERID(num)})
exten => s,2,Set(DB(LastCallTime/${ARG2})=${STRFTIME(${EPOCH},,%s)})
exten => s,3,Dial(${ARG1},30,toj)
exten => s,104,Voicemail(${ARG2})
exten => s,105,Hangup
 
[fromexternalsip]
exten => 123456,1,Answer
exten => 123456,2,Macro(dialcliexten,SIP/2000,2000)

Yes, this does cause some slight issues with groups: I haven’t got enough devices on my LAN to test that properly, but one idea I had was to store the caller id twice in the macro, with 0 being the group number (a synonym for the operator/group ring: change it if you like !):

[macro-dialcliexten]
exten => s,1,Set(DB(LastCallFrom/0)=${CALLERID(num)})
exten => s,2,Set(DB(LastCallFrom/${ARG2})=${CALLERID(num)})
exten => s,3,Set(DB(LastCallTime/0)=${STRFTIME(${EPOCH},,%s)})
exten => s,4,Set(DB(LastCallTime/${ARG2})=${STRFTIME(${EPOCH},,%s)})
...etc...

and with 1471 then reading out two numbers. This slightly deviates from the BT norm, and might need some user education but it’s not enough to simply store the number and only read out the most recent timestamp when calling 1471 as it’s possible for a group call to come in whilst one extension is in use.

Recording a couple of new voice prompts to give a result such as:

“The last number to call this extension was 01234 567890, today at 12:04pm and the last number to call these premises was 09876 543210 at 12:07pm”

might be one solution.

Update: Thanks to Steve for pointing out that SayNumber (line 5 of 1471 below) is a bad idea: it works just fine in limited testing on my LAN, but when given a normal UK 11-digit number it seems to have some trouble trying to pronounce 01234 567 890 as 1 billion, 234 million, 567 thousand 890…

Switching that command for SayDigits not only lets the function work, it also makes far, far more sense when listening to the result, too.

Ok, so I couldn’t leave it alone: here’s a macro’ed version with a modified 1471 readout that ought to trap illegal values. The only issue here is that I don’t currently have the FXO hardware and so I can’t say what the BT Unavailable, International and Withheld caller ID codes translate to in Asterisk.

All in the extensions.conf file, starting with the Macro definition:

[macro-dialcli]
exten => s,1,Set(DB(LastCallFrom/${MACRO_EXTEN})=${CALLERID(num)})
exten => s,2,Set(DB(LastCallTime/${MACRO_EXTEN})=${STRFTIME(${EPOCH},,%s)})
exten => s,3,Dial(${ARG1},30,toj)
exten => s,104,Voicemail(${MACRO_EXTEN})
exten => s,105,Hangup

And again, place these mappings in the correct context for your usage:

exten => 2000,1,Answer
exten => 2000,2,Macro(dialcli,SIP/2000)
 
exten => 2001,1,Answer
exten => 2001,2,Macro(dialcli,IAX2/2001)

Finally the new 1471 with a better date phrasing and some error checking:

exten => 1471,1,Answer
exten => 1471,2,Set(last=${DB(LastCallFrom/${CALLERID(num)})})
exten => 1471,3,Set(dtime=${DB(LastCallTime/${CALLERID(num)})})
exten => 1471,4,Playback(last-num-to-call)
exten => 1471,5,ExecIf($["${last}" != ""]|SayDigits|${last})
exten => 1471,6,ExecIf($["${last}" = ""]|Playback|unavailable)
exten => 1471,7,ExecIf($["${dtime}" != ""]|SayUnixTime|${dtime}||"Q IMp")
exten => 1471,8,Wait(2)
exten => 1471,9,Hangup

If anything, I suppose the lack of caller ID could be trapped at the start of the 1471 code and an “Unavailable” message could be played, but because this is on my own network I’m not that bothered about those cases as I will always want internal CID to be presented.

(Oops: an extra } crept in, so if you have taken a copy of this any time before the 23rd then do check your macro carefully)

Wanting to make my home Asterisk box a convergence point for VoIP and PSTN mans that I really wanted to have the “last number caller id” option that BT offer in the UK, but sadly the page on the Asterisk Wiki that mentions 1471 is no longer valid, so here’s my own implementation. It’s not 100% feature complete, but it does work in a comparable way to the PSTN version.

All the work is done in the extensions.conf file and you need to add an explicit store of the incoming CID and time before routing the call to the correct extension, so this could (obviously) be improved by using the Macro command, but that, as many of my past lecturers used to say, is left as an exercise for the reader.

In this case, two extensions 2000 and 2001 are shown as examples:

exten => 2000,1,Answer
exten => 2000,2,Set(DB(LastCallFrom/${EXTEN})=${CALLERID(num)})
exten => 2000,3,Set(DB(LastCallTime/${EXTEN})=${STRFTIME(${EPOCH},,%s)})
exten => 2000,4,Dial(SIP/200,30,toj)
 
exten => 2001,1,Answer
exten => 2001,2,Set(DB(LastCallFrom/${EXTEN})=${CALLERID(num)})
exten => 2001,3,Set(DB(LastCallTime/${EXTEN})=${STRFTIME(${EPOCH},,%s)})
exten => 2001,4,Dial(IAX2/201,30,toj)

The playback code is fairly straight forward:

exten => 1471,1,Answer
exten => 1471,2,Set(last=${DB(LastCallFrom/${CALLERID(num)})})
exten => 1471,3,Playback(last-num-to-call)
exten => 1471,4,SayNumber(${last})
exten => 1471,5,Playback(on)
exten => 1471,6,Set(dtime=${DB(LastCallTime/${CALLERID(num)})})
exten => 1471,7,SayUnixTime(${dtime})
exten => 1471,8,Wait(2)
exten => 1471,9,Hangup

Items to note:

• Correct use of the Macro command would improve this a lot, so by creating something like DialCID and using that in place of Dial would make it trivial to use for all extensions
• I have not tested this with Witheld or Blocked numbers and would expect that the SayNumber line would just say "Zero", so adding some conditional testing in there would make things nicer (test for zero CID)
• I have not tested this for the case when no call has been received before for an extension: I would assume it’s another "Zero" response, but again, more conditionals in the 1471 section would make that nicer (test for zero date)
• I find the date pronunciation quite offensive, as I am not currently in the year "two thousand seven" but "two thousand and seven" – there are options to SayUnixTime that I have yet to investigate
• I haven’t implemented the "Press 1 to return this call" voice prompt that BT have

Feel free to correct these oversights in the comments – if things get optimised a lot I’ll post an update with the best/most feature complete version.