integrate asterisk + legacy PBX

Hi All

Anyone got any experience of linking PBX's into Asterisk?

Basically the existing PBX (Panasonic hybrid IP-PBX KX-TDA100) has incoming ISDN (2 channels which give 4 voice lines I think) as well as about a dozen extentions. I need to know how I can integrate this with Asterisk. Ideally I would just get rid of the thing but I can't.

Thanks

Analog cards in the Asterisk server could connect as extensions on the PBX or could act as analog trunks to the PBX.

Give us a few more clues about what the scheme is.

Can the Panachronic act as an h.323 endpoint at all?

Hi Yarwell

Basically, a new building is going up. The telephony in this building will all be VOIP (that is.. if I can somehow integrate the old stuff).

Now, the analogue PBX is in the old building. I can't get rid of that because as I say it has the 2x ISDN going into it as well as all the analogue extensions. I don't want to entireley replace this PBX with Asterisk because it's in an insecure location.

My main issue would be:

a) What would it take to allow people using the Asterisk system to get an outside line, so we're going Asterisk -> PBX -> PSTN (and vice versa)

b) Also what would it take to allow internal calls between asterisk <-> pbx users? I guess this could be achieved after having done point a)

For a) you would have normally route the calls out on a VOIP trunk rather than using the scarce resource of the ISDN line.

If you had an analogue interface card in the asterisk box with FXO modules it would connect to extension lines from the Panasonic, or to incoming analogue PSTN if available (I've done the latter, not the former).

You could configure the above so that a VoIP extension user dialling an 01xxx xxxxxx number would be trunked out to a VoIP service with fallback to the PBX if the VoIP trunk was down or busy. The trunk pointing at the PBX would need to add any PBX prefixes like 9 for an outside line.

To force a call out the PBX from a VoIP phone you could prefix the number with an 8 or 9 or whatever to tell Asterisk to use the PBX trunk.

b) pbx -> Asterisk user calls would be handled by the same FXO port(s) on the asterisk receiving calls from the PBX extension users. It would route these to the Asterisk users in the same way its going to have to accept incoming calls. Perhaps the pbx user will dial 8 for an asterisk user followed by their asterisk extension number.

Asterisk -> pbx user calls would be handled by trunking calls to pbx extensions out to the pbx via a prefix or dial plan. A more elegant solution would be a "virtual extension" on the Asterisk system that when dialled by another * user called a pbx extension.

OK, cheers Phil. It seems I'm limited because there's no way I can "physically" link the PBX and asterisk box for the trunking, unless I run a bunch of coppers between the 2 buildings.

So would you say it would make more sense if I just got rid of the ISDN and used trunked VoIP over the internet from asterisk? I suppose we could consider replacing "legacy" extensions that were on the old PBX with WIFI SIP handsets? We have blanket coverage for that.. at least then I'm not faffing around with multiple systems trying to talk to each other

OR.. do you know how much the going rate Bt charge to relocate ISDN NTE's?

Edited by ste__ (Sat 24-Nov-07 16:38:50)

hey hunnymonster, i think for it to be h.323 compliant i would need to stick a card in it, will double check though.

I'm slightly confused becasue surely if you move the ISDN lines to the Asterisk server the extension lines are then stranded where the PBX was ?

I don't know where your inbound calls sit in all this either.

I wouldn't use WiFi sip phones personally, use DECT with either an ATA or something like the Siemens combined landline/DECT phones.

BT have a standard charge for shifting NTEs, it is 99 visit charge plus 74 quid per NTE, all plus VAT.

Surely, If the exhange can support analogue trunks then you could just pop a couple of ATAs at the PBX and plug them into the LAN.

Phil, thank you for all your input.

One thing is currently stopping me from moving forward with asterisk, and that is the handsets themselves.

Now, I was under the impression that I should be looking at SIP handsets.. is this the case? As there are also IP handsets what's the difference?

Also could you recommend any decent handsets (hard wired) that work well with asterisk? I would be looking for one operator console that eg the receptionist could use (if one can be used with asterisk) and a bog standard phone for other office cretins

Thanks

Edited by ste__ (Tue 11-Dec-07 18:13:12)