Asterisk PABX and LD Dialling. - UK Vintage Radio Repair and Restoration Discussion Forum

julie_m · 2nd Sep 2011, 10:46 am

Split from this thread:-

https://www.vintage-radio.net/forum/...d.php?p=462232

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It's not necessarily all doom and gloom for vintage phone collectors, even if your phone line is DTMF-only.

Not long ago, I acquired a TDM410P clone (a PCI card that interfaces to up to four devices, either phones or exchange lines, by means of plug-in modules) and set up an experimental Asterisk PABX -- and was delighted to discover that it will quite happily accept loop-disconnect dialling, and is not fussy about timing. I even built a simple voice menu application, and it quite happily accepted pulse-dialled selections.

But when Asterisk dials out over the PSTN via an FXO interface, it uses DTMF signalling -- even if the call was sent to Asterisk in LD.

Now, this is much, much more than just an overgrown pulse-to-tone converter.

A card with three FXS modules (Foreign eXchange Station -- connect to phones) and one FXO module (Foreign eXchange Office -- connect to line) will turn a scrappy 1GHz PC into a fully-featured PABX; allowing you to show off 3 vintage telephones in such a way as they are able to call each other (which you wouldn't be able to do if you just fit pulse-to-tone converters inside the phones), or the outside world.

You should be able to get the card, and a suitable machine to run it if you haven't got one already, and still have change from £100. Search in the usual places .....

OscarFoxtrot · 2nd Sep 2011, 3:53 pm

And if you fit a soundcard and internal speaker to the PC you can even make it play Strowger noises as it connects.

Pellseinydd · 3rd Sep 2011, 2:19 pm

Be aware that not all the FXS/FXO cards that slot into a PC for use with Asterisk work with pulse dialling.

Ones that we know of are the Digium TDM400/410 and most of the clones thereof.

The Openvox 4 port, 8 port and 12 port cards - haven't tried the 24 port (it bit pricey!)

The Sangoma range

The Yeastar TDM4oo and TDM800 do but their larger cards don't. I know someone who who bought a couple of TDM1600 ones to use with a Strowger exchange but didn't ask if they worked with pulse! They didn't and he lost in excess of £1500 ! Yeastar couldn't help and seem to have stopped producing the TDM1600 16 port card.

We have a network of Asterisks linking old Strowger exchanges - see www.ckts.info/192/uk - and hence have some experience of working with 'pulse dialling' and Asterisks. There are old Strowger and other exchanges connected around the World.

2nd Sep 2011, 10:46 am	#1
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Asterisk PABX and LD Dialling. Split from this thread:- https://www.vintage-radio.net/forum/...d.php?p=462232 ----------------------------------------------------------------------- It's not necessarily all doom and gloom for vintage phone collectors, even if your phone line is DTMF-only. Not long ago, I acquired a TDM410P clone (a PCI card that interfaces to up to four devices, either phones or exchange lines, by means of plug-in modules) and set up an experimental Asterisk PABX -- and was delighted to discover that it will quite happily accept loop-disconnect dialling, and is not fussy about timing. I even built a simple voice menu application, and it quite happily accepted pulse-dialled selections. But when Asterisk dials out over the PSTN via an FXO interface, it uses DTMF signalling -- even if the call was sent to Asterisk in LD. Now, this is much, much more than just an overgrown pulse-to-tone converter. A card with three FXS modules (Foreign eXchange Station -- connect to phones) and one FXO module (Foreign eXchange Office -- connect to line) will turn a scrappy 1GHz PC into a fully-featured PABX; allowing you to show off 3 vintage telephones in such a way as they are able to call each other (which you wouldn't be able to do if you just fit pulse-to-tone converters inside the phones), or the outside world. You should be able to get the card, and a suitable machine to run it if you haven't got one already, and still have change from £100. Search in the usual places ..... __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

2nd Sep 2011, 3:53 pm	#2
OscarFoxtrot Heptode Join Date: Apr 2011 Location: Edinburgh, UK. Posts: 805	Re: Asterisk PABX and LD Dialling. And if you fit a soundcard and internal speaker to the PC you can even make it play Strowger noises as it connects.

3rd Sep 2011, 2:19 pm	#3
Pellseinydd Heptode Join Date: Jul 2007 Location: Flintshire, UK. Posts: 707	Re: Asterisk PABX and LD Dialling. Be aware that not all the FXS/FXO cards that slot into a PC for use with Asterisk work with pulse dialling. Ones that we know of are the Digium TDM400/410 and most of the clones thereof. The Openvox 4 port, 8 port and 12 port cards - haven't tried the 24 port (it bit pricey!) The Sangoma range The Yeastar TDM4oo and TDM800 do but their larger cards don't. I know someone who who bought a couple of TDM1600 ones to use with a Strowger exchange but didn't ask if they worked with pulse! They didn't and he lost in excess of £1500 ! Yeastar couldn't help and seem to have stopped producing the TDM1600 16 port card. We have a network of Asterisks linking old Strowger exchanges - see www.ckts.info/192/uk - and hence have some experience of working with 'pulse dialling' and Asterisks. There are old Strowger and other exchanges connected around the World.