Enable RTP-UDP (port range is 10,000-20,000).

• Enable SIP-UDP/TCP port 5060.
• Make sure that there is no SIP inspection/SIP transformations enabled depending on your firewall.
• Turn off ALG (Application Layer Gateway).
• To automatically instruct the phone with the provisioning URL you need to program ‘option 66′ on your DHCP server with the following address “http://cprx3.hostedsip.net/pv”.
• Apply QOS on your firewall or router

Hitron CGN3 (Rogers):

Compatibility: NOT Compatible
Status: This router does not have the ability to disable SIP ALG and is not compatible with VoIP. This router will need to be replaced with a router that is compatible. If you check the Hitron web site they suggest it is possible to place a phone on the DMZ, but, this is not advisable as it will compromise the security of the phone.

Motorola Surfboard
Compatibility: Compatible after changes
Recommendation: Disable SIP ALG and ensure appropriate firmware (see below)
Status: The following changes (or checks) are required:

1) Must be running firmware v3.3 or above
2) Must disable SIP ALG