NEC SL2100 Router WAN dynamic ip address issues with offsite IP telephones 1

[testman1]

With the NEC SL2100, if I use a WAN dynamic ip address in the Router I periodically lose offsite IP telephones connectivity.
I have started to use DDNS addresses in the router and IP telephones. That corrects most of the problems.
The only problem left is the ip address in 10-12-07. It will only let me put in an ip address. I can't put in the DDNS address.

Is there a work around, or when using offsite ip telephones with the SL2100 the routers needs to have a static ip address.

 

[belevedere]

With off site IP phones the router needs a static address. The system can only use IP addresses. It cannot do a DNS. As for 10-12-07, it should be able to take any valid IP address. Make sure that 10-63 is turned off and you have 2 static addresses in the system in 10-12-09 and 84-26. Set up port forwarding in the router, 5080 + 5081 UDP to 10-12-09, and 10020-10147 UDP to 84-26, and turn off SIP ALG.