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New Member

FXO to PBX connection

What is the best way for me to connect my VOIP network to an existing Nortel Norstar Modular ICS 4.0 I have a 3700 with 2 FXO and 2 FXS ports. My pbx has a E&M trunk module installed. Where do I connect to on the PBX side (are there pinouts), and does the pbx need to be reporgrammed? BTW, my VOIP network is a Lab setup while I study for my CVOICE..


Re: FXO to PBX connection

You would need an E&M VIC in your 3700 to connect to the Norstar E&M. If the the Norstar has analog phone ports you could connect them to a router FXO.

New Member

Re: FXO to PBX connection

Your MICS should have atleast one analog station port in it, possibly two. I can't remember right now how many are builtin. Anyhow what you would want to do is tie an fxo on the router to an analog station port on the MICS and then tie an fxs on the router to an analog trunk port on the MICS. To the MICS the FXO appears to be an analog station and the FXS appears to be an analog CO trunk. I know it seems reversed but if you think about it the FXS expects to provide dialtone and the analog trunk on the MICS expects to get dialtone from the PSTN. The reverse is also true the analog station on the MICS expects to provide dialtone when it the end device goes off hook and the fxo port on the router expects to get dialtone when it goes off hook. At that point you need to config the MICS so that the port the FXO is tied to is in a different line pool and assign a seperate line code to that pool. Now when you want to call a user on the PSTN you dial your normal line code (say 8) then your number and if you want to call an IP pone you dial the new line code (Say 9) and the ext number.

You could get more creative by creating various routing rules in the MICS so that you could actually use the same line code no matter what but this solution is far more simple. We did the exact same thing here with MICSs and CICSs while we were in the process of migrating to a pure CallManager Setup and it worked quite well. If you have any other questions feel free to ask.