Asterisk and 3com NBX

I have a spare 3com 3C10114C which is a 4 port analog FXO card. It used to be connected to the PSTN, but we went PRI and didn’t need the additional cost of 4 analog lines so it’s just lying around unused at the moment.

I’d like to test Astersik and SIP trunking with an SIP provider, but not have to replace our current NBX system. We would like create an SIP trunk between a SIP provider and the Asterisk box and an analog trunk between the Asterisk box and our 3Com NBX.

I’m under the impression in theory this could be done using the spare 3Com FXO card and a Digium TDM400P Analog port card. A little confused at which particular TDM400P package we would I want to get? The one with 4 FXS ports?

Haven’t read anything about anyone attempting to connect Asterisk to an NBX. I thought I’d give it a shot. Eventually we would probably want to connect the NBX to an Asterisk box using a T1 card, but for proof of concept we’d like to start small and inexpensive with analog.

FYI, our NBX is running NBX R4_4_7, so SIP trunking between the NBX and an Asterisk box is not an option for us.

Also if anyone has done this or sees a problem with my logic please let me know.




Maybe I should be a little less specific with which PBX I’m trying to connect to Asterisk.

Pretend I have a PBX with a 4 port FXO card. Which Digium TDM400P version card would I need in an Asterisk box to connect it to the 4 FXO ports on the existing PBX?

You would need a 4 port FXS card so a TDM40B would be the one uyou want.

If its just a POC you could just get a one or two port to save a few bucks. Just replace the “4” in the above number with the number of FXS ports you want (up to a total of 4 for that card or 8 for the 8 port card).

We’re wondering about this scenario now especially since we noticed that 3Com now sells an Asterisk box.

I’ve now got an FXS card in a test machine and Asterisk installed. I’ve got the FXO card installed in the NBX. That’s as far as I’ve gotten so far. The LED status indicators on the 3Com FXO card shows the card is detected, but it’s not showing up in the NBX web-based admin like it should be. That’s a whole other issue that I’ve got going on in a NBX related forum. Once I get that side figured out then I imagine I’ll come back here with Asterisk related issues. Hopefully though the Asterisk side will be issue free.

I’ve also wondered about the 3com version of the Asterisk box. I wouldn’t mind replacing our NBX’s with those as long as I know it can support all the 3Com phones we have and the number of users we have. Probably about 40 phones at each office. Maybe 10 in use at any given time.

Replacing everything is kind of a pain though. Hence the band-aid method of using analog or digital trunks between the NBX and an Asterisk box. Once the trunks get setup it only requires altering the dial plan a bit on the NBX.

In case anyone else could benefit from my NBX side of this experience so far here is the link to the thread regarding that. … erthread=y

At this point I seem to have the Asterisk box and NBX physically connected but I haven’t done any sort of configuration yet.