Mitel 5000 and teleworker's remote 5330e IP phone issue

[pie8ter]

We have a 5000 unit supporting 100 Mitel 5430 and 5330e IP phones at our central office. 

I have a branch office with three 5330e's.  They are behind a Sonicwall NSA 250M firewall.  Timewarner said their modem forwards (bridges) all the traffic to sonicwall's WAN ip number.  An employee at the branch can make a call.  The person at the other end can hear the employee but can't respond.  The employee can't hear the person at the other end.  In the past, I asked the teleworkers to set their DSL/Cable modems' DMZ mode to point to their router's IP number or the phone's IP number.  Almost all the teleworkers have a low end router like linksys, netgear and so on.  The phones works fine with them.

As a test, I put the branch office phones directly on the cable modem, both parties can hear each other fine.  The problem starts when the phones are behind the sonicwall.  So the sonicwall seems to block something or don't know how to dynamically allow/close ports for the Mitel system.   Sonicwall is widely deployed in businesses, particularly in branch office situations.  There must be a NAT/firewall config I am missing. 

Thanks

[bhackbarth]

One-way audio is usually a NAT issue. Those lower end (Linksys) routers don't block anything going out by default, but I'm fairly certain every Sonicwall I've worked with does.  On the Sonicwall use Firewall rules to ensure the following ports are allowed to go out to your 5000's public IP:

UDP: 69, 20001, 6004-6261, 50098-50508

TCP: 3998-3999, 6800-6802


Of course, on the router that is in front of your 5000, these same ports need to be configured to allow traffic in and forward to the 5000.  Also of course, your 5000 must have its public static IP set in DB Programming both in System->IP Settings   and    System->Devices and Feature Codes->IP Connections->P6000.

[PC77375]

I think you would also want to make sure that the phone is set to NAT mode in DB Programming.