General Router Setup

Ensure you are NOT in a Double NAT situation.  ie.  You do not have one router operating behind another router.  For example, you want to put a Charter modem/router combo box into Bridge Mode, so that it is acting only as a modem, not a router, then, setup your dedicated router or firewall between the Charter modem/router combo box and the rest of the network.

Disable SIP ALG.  Sometimes this is called SIP Transformations or otherwise.

Allow traffic to/from the following servers:

Name:                    IP Address:
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Ringfree Server 1 209.51.167.251
Ringfree Server 2 209.51.167.254
Ringfree Server 3 70.36.23.125
Ringfree Server 4 70.36.23.123

On the following ports:

UDP, Ports 5060-5061 and 10000-20000

Where QOS (Quality of Service) options are available, prioritize traffic to/from those IPs, on those ports.  Reserving 10% of the available bandwidth for phones is ideal, but not always necessary.  At a minimum, reserve 120k of bandwidth for each expected simultaneous phone call.