Using Asterisk alongside an old BT PBX
 

At work we have a BT Inspiration and it's great for what we need it to do.
However, it doesn't have a voicemail module, we have no means of recording calls, we can't do an IVR, we can't redirect the MANY, MAANNYYY sales calls we get to Lenny etc etc etc.

However, I'm wary of ripping out the Inspiration and replacing with Asterisk and Cisco phones because - for the most part - the Inspiration is fine and we have the featurephones already.

Can anyone advise...is it possible to use a hybrid system and what benefits (if any) and what caveats does that bring?

Thank you

Re: Using Asterisk alongside an old BT PBX
 

You could put the Asterisk between the PSTN line and the Inspiration to 'filter' the calls and send the 'junk' ones off for Lenny to deal with! All you need is a Raspberry Pi running Asterisk and an ATA (such as a Linksys SPA3000 or SPA3102) with an FXS and FXO port. FXO port goes to PSTN line and FXS goes to an exchange line port on the Inspiration. Set Asterisk up to deal with the incoming calls and if OK to ring the FXS port o the ATA. If not OK to send the call to 'Lenny'. Outgoing calls from Inspiration to 'hotline' straight through Asterisk to PSTN line with no code.

For those not sure who Lenny is, he's a great old guy who is an expert at dealing with telemarketers. Does it all as a volunteer. Long since retired, he's always happy to chat on his PSTN number - 01686 888 123 !

Re: Using Asterisk alongside an old BT PBX
 

Asterisk is awesome! If you ever messed with phones when you were younger, Asterisk is the mythical "sky blue pink box with yellow spots on", and then some more. It got there first and it was already Open Source, which avoided the possibility of multiple deliberately-incompatible competing proprietary standards. You cannot wind up locked into a single vendor's ecosystem, nor locked out of features it's entirely capable of supporting if you just pay for a licence.

You can get analogue line cards that plug into a PC running Asterisk, which then accept a number of modules; either FXO to connect to an exchange line, or FXS to connect to an analogue telephone. There are also unofficial clones available if you look, which are lower-cost and fine for experimental purposes but I wouldn't advise anybody to use one of them for running business-critical services. At least have a spare handy if you are going to chance it.

If you have at least one FXO and one FXS port, you can sit your Asterisk box between the exchange line and the PABX to act as a fancy answering machine out of hours, or (if you are into PHP or CGI scripting) as configured via a web interface. A second FXO port would allow you to connect your Asterisk box to the PABX as an extension, allowing messages to be retrieved by dialling into it.

The next logical upgrade would be to replace the analogue phones and PABX with VoIP phones added to Asterisk as extensions.

The final phase would be to have your number(s) transferred onto a SIP trunk instead of the PSTN. Your SIP trunk provider will be able to arrange this, and also provide stanzas to paste into your various configuration files (such as /etc/iptables/rules to open the necessary ports just to their IP addresses and not any random hacker, /etc/asterisk/extensions.conf to set up a context for incoming calls and rules for routing outgoing calls and /etc/asterisk/pjsip.conf to create a SIP endpoint for the trunk). You will be able to route outgoing calls over the SIP trunk even before the incoming number is transferred, so it will be possible to run the two systems in parallel and switch over as seamlessly as possible.

Re: Using Asterisk alongside an old BT PBX
 

Thanks! Lots of food for thought, here! Anyone know if the BT Inspiration featurephones will work as a dumb phone if connected to POTS (or in this case not POTS at all; Asterisk and a Linksys ATA!) ?

Re: Using Asterisk alongside an old BT PBX
 

I doubt it.
It's not a system I had any dealings with, but I think the feature-phones are hybrid, meaning analogue voice and digital signalling on two separate pairs of wires.

Re: Using Asterisk alongside an old BT PBX
 

Whereas you can use a normal telephone with Inspiration/Revelation PABXes using the voice circuit on terminals 2 and 5 of the four-wire output, the featurephones require the additional data pair on 1 and 6 to work correctly.

I'm not sure whether even the voice circuit works on a featurephone without the data pair connected.