FXS, FXO or E&M ? I don´t know which to use

[lveraza]

Hi, I haven´t understood the concept about these ports,

I want to comunicate thress offices with 1751v routers(VoIP), but in each office exist PBX, which type of port i must to use if i want to call from my phone in mi room up to the room in other office ?

Can i use 827V with FXS port ?

Thanks

Best Regards

Luis

[msheik]

As you have PBX mostly you have to use E&M ports.But the one of the design considerations is no# of simultaneous calls between locations.I remember 1751v supports 2 Voice ports.You just need the voice ports and the proper IOS for the router for this VoIP to work.

Cheers

Mehboob