BCM400 with Remote IP Phones

[iwant750]

I have a BCM 400 with several sites connected that work fine over the Public Interface. I am looking at setting up some home users through VPN (Sonicwall), however when the phones connect there is one way audio. I make make a call and my voice is heard, but I cannot hear the other party. Im pretty sure its a routing issue, I just dont know if it's in the BCM or the routers.

 

[snd1234]

Probably a firewall issue. Even though you would think the PBX would be the medium, The phones actually need to be able to talk to each other directly. So anything between the two phones needs to have clear UDP ports. I forget which ones but my suggestion is that you start troubleshooting your firewalls to see what is being blocked.

 

[ucxguy]

The default range for RTP (media) ports is something like 28000-28511.

For the remote IP phones, do you use i2050 or some real phones? If you use i2050, you'd need only VPN from the PC that is running the soft phone to the office network. If you use a hard phone, you need VPN between the home router and the office router.

 

[telcodog]

Been a while since I had to look at a 400, but try having a look under Configuration>Resources>Port Ranges (assuming you have a release 4.0). All the information you need regarding ports are listed there (can't remember if it has that particular option though).

Just in case it doesn't, the ports you need are:

RTP over UDP 28000 to 28249
30000 to 30099

UDP 20000 to 20249

Signalling 0 to 1023
1718 to 1719
2216 to 2227
5000
7000
60000 to 60240

You won't need all of them for remote phones, like signalling, you only need 7000.

 

[iwant750]

Thanks for the reply. I need to clarify some things. The phone is a 2004. There is a VPN established through two Sonicawalls between the home office in question and corporate. Both LAN interfaces on the BCM have IPs. One is a 10.x.x.x behind the firewall, the other is a public IP with no firewall. The published interface is LAN2 (public). If I change the published interface to LAN1 the phone works as expected over the VPN, but the phones that connect to the LAN2 interface will no longer connect. I need both scenarios to work.

 

[ucxguy]

What is the configuration of the i2004 phone? Is it configured to connect to the internal IP address (10.x.x.x)? When you have the VPN between the home network and the office network, you should configure the phone S1/S2 values to the internal address (not the public one).

 

[DBrewsky]

This is NOT a firewall issue!! This is a NAT'ing issue! You cannot use the BCM as a pass-through. By default ALL voice traffic needs to have a direct route to each other. This is design intent. To resolve this issue using VPN's, make sure each remote location has a tunnel built to the other locations. Each remote must have a tunnel to each other remote location. Once you get this, you will get the two-way voice you are wanting.

The only other way to resolve this is to upgrade to BCM450 Rls 6.0 and use the Remote Worker feature.

--DB