VoIP from the modems rj-12 jack



  • Hey guys.

    I have a question I have a modem (which is currently in bridged mode to a PFSense box) that also comes with a rj-12 jack for the old phone services(which comes with it's own phone number).
    My question is how can use that in conjunction with the PFSense box to make a VoIP server?
    I know we can make a VoIP server in PFSense by installing asterisk but how do I configure it with a normal network card to use the rj-12 jack for external communication?

    I know I'm sounding kinda vague but googling around only gives me how to configure the VoIP service, can someone please help me?



  • Your modem is not an ATA adapter, which is what you want.

    The RJ12 port is just passthrough. It doesn't modulate/demodulate any voice.



  • @moikerz:

    Your modem is not an ATA adapter, which is what you want.

    The RJ12 port is just passthrough. It doesn't modulate/demodulate any voice.

    Maybe I did a poor job explaining myself.

    I have a modem it has a phone number ,etc…
    What I want to do is plug that rj12 connection that comes from the modem into the pfsense box to then use asterisk to setup the local VoIP network and then setup all the phones to to receive calls from that number.

    This is the part that I want to know, can I just plug in the rj-12 into the pfsense box and can I configure asterisk to do this or not?
    This is because I recently upgraded the network and removed all the phone lines from my house and I am heavily considering getting  VoIP phones.



  • No, you would need a special interface card that Asterisk would communicate with for the purpose of making/receiving phone calls on that line. There are two different kinds of ports that can be found on analog cards… FXO (line) and FXS (station). You want a card with FXO ports to be able to use the analog phone line. If you had analog phones that you were using through your Asterisk system, those would use FXS ports. FXS ports need to provide a bit of electrical power for the analog phones attached to them, while FXO ports don't.



  • @ultimateon:

    I have a modem it has a phone number ,etc…

    You need to figure out how this voice part of your modem is configured. Generally there are 2 common options - this internal VoIP GW may use either Internet VLAN or it's own 'voice' VLAN. In the 1st case you will just need SIP credentials extracted from your modem, in a second - you will also need to bring your voice VLAN to pfSense and route it further to your Asterisk. Forget about the jacks ;)



  • @virgiliomi:

    No, you would need a special interface card that Asterisk would communicate with for the purpose of making/receiving phone calls on that line. There are two different kinds of ports that can be found on analog cards… FXO (line) and FXS (station). You want a card with FXO ports to be able to use the analog phone line. If you had analog phones that you were using through your Asterisk system, those would use FXS ports. FXS ports need to provide a bit of electrical power for the analog phones attached to them, while FXO ports don't.

    By any chance are there any FXS port adaptors for USB that pfsense(or FreeBSD) recognizes properly OOB?

    @AndrewZ:

    @ultimateon:

    I have a modem it has a phone number ,etc…

    You need to figure out how this voice part of your modem is configured. Generally there are 2 common options - this internal VoIP GW may use either Internet VLAN or it's own 'voice' VLAN. In the 1st case you will just need SIP credentials extracted from your modem, in a second - you will also need to bring your voice VLAN to pfSense and route it further to your Asterisk. Forget about the jacks ;)

    Unfortunately the modem doesn't come with VoIP and it keeps it SIP gateway closed up although (The ISP doesn't actually provide VoIP directly but provides services using it, complicated stuff)
    So ill have to go ask Jack if he's willing to phone PFsense.


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