Newbie Questions about Asterisk configurations (Australia)

From what I’ve read about Asterisk it can be connected to a Telstra ISDN 10, 20 or 30 connection to enable VOIP to POTS communication, is that correct?

If so, could the following scenario work:

  1. You have a main office that has a Telstra ISDN 10, 20 or 30 connection connected to your Asterisk PBX. All the internal users use VOIP for internal calls and use the ISDN to allow internal calls to communicate with POTS phones on the outside and outside POTS phones to communicate with the internal VOIP phones.

  2. You have a remote branch office (10 - 15 employees) connected through an ADSL VPN to your head office. The question is, could those remote users utilise the services of the Asterisk PBX over their VPN connection to the head office without having a local Asterisk PBX configured at the remote office? In other words, they could call a POTS number and the information would transmitted over the VPN to the Asterisk PBX located at head office and routed through the ISDN connection to the outside POTS number.

Any help with the above would be greatly appreciated.

Cheers, Ian

From what I’ve read about Asterisk it can be connected to a Telstra ISDN 10, 20 or 30 connection to enable VOIP to POTS communication, is that correct?
Well I cant say for sure but that is what I read also for more go here looks like several topics on this … tnG=Search

As far as the senario it should work but bandwidth will be a key issue in call quality and how many simultaneous calls you want between offices


Cheers, Ian


Yes to (1) and a hmm to (2)

  1. Being a pom (5-0 to the Aussies - Ha ha!) I’m not quite sure what a telstra 10/20/30 is, but I’ll take that to mean an ISDN30 connection delivered with 10/20 or 30 channels. This will work fine, we run around 20 phones (snom 190s) internally connecting via the LAN to the Asterisk box and then a 12 channel ISDN30 back to POTS land.

Callers ring our main number or DDI’s and asterisk picks up the calls and devliers to the appropriate snom phone. You need decent quality kit though as the last thing you want in a volume call application is for the server to fail. We spent around 4K STG on our main server - ok so it’s got 2gn RAM, 2x 200GB RAID, 4x XEON 2.8 processors etc, but we take / make some 500 calls per day.

To date our only issue has been when a problem with our exchange server flooded our network with iffy packets and our phone service went down the toilet for around 90 minutes.

  1. In theory yes, in practice I would say you would die a bandwitth death using just ADSL. In the UK its 256k upstream, so you remote office could probably have a maximum of 4-6 effective calls running at the same time. If peoeple call each other a lot at the remote site (‘internally’) but these calls are having to trunk to from the asterisk box, that will suck.

I’d suggest if the budgest there that you have another smaller asterisk box at the remote site, perhaps with POTS connecitvity (4x ISDN2 channels or similar) - then you’re office to office comms goes between the asterisk boxes and PSTN is handed off locally for outbound. Routing calls from the main site to remote site seamlessly is doable, but again watch the bandwidht

I suggest you get some expert to set it up however, especially if phones are mission critical to your business - that’s what we did and I am pretty happy with it.