ringback

New feature! Faultsmans Ringback on VoIP Phones


A “faultsmans ringback” facility is useful for testing that you’re able to receive incoming calls. The idea is that you dial a special number, hang up, and the exchange calls you back.

On our UAX13 strowger exchange, we use this relay set: http://dfrtelecoms.org.uk/ex002.htm and a similar relay set on our PABX4 based exchange: http://dfrtelecoms.org.uk/ex027.htm – but on the asterisk phones we didn’t have a solution.

Until now!

If you dial ‘9#’ from any of our asterisk phones, you should hear a 3 tone “doo… dah… Dit!” sequence, which will repeat until you hang up. There should then be a short pause before your phone rings to indicate an incoming call. If you pick the handset up you should hear dialtone (although you won’t be able to dial any numbers)

The facility is still new, and we’re still ironing out a few wrinkles, but try it and let Paul know how you get on.

For anyone interested in asterisk, it’s based on the following dialplan contexts:

...
exten => 9,1,Goto(SIP-ringback,s,1) ; Faultsmans ringback
...

;======================================================================
[SIP-ringback] ; This context (and SIP-ringback-complete) do faultsmans ringback
;======================================================================
exten => s,1,Answer()
exten => s,n,Set(RINGBACK=${CALLERID(num)})
exten => s,n,Log(NOTICE, Ringback requested for ${RINGBACK})
exten => s,n,Wait(1) ; Wait 1s for the audio to connect
exten => s,n,Playtones(950/330,0/15,1400/330,0/15,1800/330,0/1500) ; "Dooh Dah Dit!"
exten => s,n,Wait(10) ; Play 10S of the above tone before hanging up
exten => s,n,Hangup()

exten => h,1,Log(NOTICE,Executing ringback for ${RINGBACK})
exten => h,n,Wait(3)
exten => h,n,Originate(SIP/${RINGBACK},exten,SIP-ringback-complete)

[SIP-ringback-complete] ; Used in conjunction with [SIP-ringback]
exten => s,1,Answer()
exten => s,n,Playtones(350+440) ; Dialtone
exten => s,n,Wait(10)
exten => s,n,Hangup()

There are a few knotty issues in the above, which mean that it’s not quite as predictable as it might seem at first – but I’ve got plan for ironing those out…