sundance-communications.com/forum Forums TDM Business Telephone Systems NEC Telephones & Systems SV9100 IP phones

Looking for a little help on the DT800 IP phones. We have a system in place and using both digital and IP sets. The DT800 sets on the system on the internal network works great. It is outside of the network where we are having troubles. We are getting the error "can't send RTP Packets". The set powers up and links to the cabinet. You can call out and it will ring the number you are calling then hangs up giving this error. Their IT department says they have all of the port forwarding done. They are using a FortiCleint firewall.

Any thoughts.

Are these phones on a VPN or NAT??

We are using NAT.

In the IP Phone setting under extension 15-05 or something you have to click NAT. Also port forwarding on router has to be 5080-81 IP of system and ports 10020-10531 to IP of media gateway. You also need to set the public IP of the system in the network setting on the CPU.

Yes we have all of these settings in 15-05 for this set. If you intercom this set from a digital set it will ring and show the extension that is calling, but there is no audio as well.

We have been going over all of the programming but on the SV9100 it just does not want to work correctly.

Do you have more than 1 remote IP phone at the remote site?

No we just have the 1 set here in our office for testing to make this work.

No RTP/UDP means no voice. Simple thing DMZ your IP phone at you office and see if that works. You also have to program the IP phone in NAT Transversal Mode Dynamic, WAN Mate IP address (the public IP of the system and WAN SIP mate port 5080.

I'm not sure about the FortiClient firewall, but I've had similar issues with Watchguard - the settings were all correct but the firewall was still blocking the ports...

We are starting to think it is the firewall that is blocking still. We have there IT department checking everything. We have done this many times on the SV8100 with out troubles.