I’m migrating my small office (10 phones) off an old Cisco POTS IP-PBX to FreePBX and trying out Nexmo elastic trunking.
I’m trying to configure an Edgemarc 2900 SBC, but I’m finding the interface a little esoteric. Things like blacklisting/whitelisting, firewall rules, DMZ, aren’t configured in any way I’m familiar with. As of now, I have the ALG turned off. I can register with the provider and make outgoing calls with two way audio. I cannot call in. When I call in I just get silence for a while before the call terminates. Looking at the asterisk console (asterisk -vvvvvr), nothing is coming into the PBX which makes sense since I haven’t told the router to send it anything.
When I try to configure the ALG using Edgewater’s guide which seems to be their recommended way, I lose registration. I’ve been tinkering for a while, but can’t figure it out. Am I correct that my three options are, setting up the ALG, putting the PBX in a DMZ, or port forwarding?
Any guidance would be greatly appreciated. Thank you.
Two choices. SIP ALG is always wrong for the server.
The firewall in the PBX Is good, especially if you can whitelist your provider and otherwise block the script-kiddies from getting access to your SIP port.
If you want to use your Cisco phone, I recommend the Chan-SCCP-B driver from GitHub. I wrote the article on connecting it to FreePBX and I’m still here helping out if needed. If you are tempted to use the phone in SIP mode, I’d recommend slamming your hand in a car door, then replacing the phones with something that works reliably with SIP.