VoIP at home to PBX

[canadianicon25]

Here is the diagram:

VoIP phone----switch---router1---CLOUD---router2---switch---VoIP PBX
and PC's

Want this setup to work. Connection from cloud to router2 is dedicated DSL. Connection from cloud to router1 is multipurpose DSL.

Need help with NAT setup for this. What I want to do is: On router2 I would static NAT the public address of router2 to the private address of the VoIP PBX. I would also static NAT the private address of the VoIP PBX to the public address of router 1 and make use of the default gateway confi'gd on router2.

On router1 because of other devices I wouldn't want to send all traffic to the phone so static NAT is out. Is port-forwarding the only option for traffic headed from the cloud to the VoIP phone?

 

[jlazzaro]

what kind of VoIP system and make/model routers? the easy answer is a type of VPN, or IP Phone SSL VPN on Cisco phones 🙂

the trouble with VoIP and NAT is the large number of negotiated UDP ports (for rtp media) required to be forwarded. check the PBX model for the defined port range and possibly reduce it. forward the required UDP media ports and signaling traffic (SIP, H.323, etc) to the phone on router 1.

there are protocols to take care of the forwarding for you (STUN/TURN and H.460) but support is not widespread and ymmv. also, assuming CLOUD = Internet, i wouldn't put my VoIP PBX on a static nat without some type of way to control traffic or a dmz architecture.