[Asterisk-Users] SIP client cannot connect to Asterisk

[K Wong]

Hi:

We have got SIP clients connecting to our Asterisk fine with a DSL
connection behind router (NAT), but when we bring the Sipura 2000 ATA
to a Rogers Cable connection behind a Netgear router (NAT), the SIP
clients aren't able to reach the Asterisk at all.

We enabled the SIP debug in Asterisk, and it doesn't see any request
coming from these SIP clients, and we also tried the to use a XTEN
Lite to connect to Simpletelecom within this network and it fails to
register as well.

It seems to be a network configuration problem, but there isn't much
log in the router that we can dignose as the Netgear router WR814 only
logs TCP web requests.

Does anyone know what the problem could be?  Does Rogers Cable blocks SIP ports?