On "Extensions" screen, phone is showing at wrong IP address


Good evening.

This phone system has been in place for almost three years, most of them trouble-free. It’s a 6102 with the very latest firmware. The phone is a Yealink T26P.

Client says the phone neither rings on inbound calls nor can make outbound calls. Phone shows as “idle” and “available” in the UCM extension screen. On the phone itself, on the account page it says “registered.”

However, on the UCM extension screen it is showing as being connected from the IP address of the LAN’s router, not the static IP that the phone is assigned when connecting to the LAN. It shows as port 1024, when the assigned port in the account settings on the phone is 5060. It does connect through a Netgear WiFi device, so that could be part of the problem - but it’s been running fine that way for a long time.



Where is the phone in relation to the UCM, local or remote?
In the phone, is the SIP server the IP of the UCM or a FQDN?
If a FQDN, where does it resolve to from the same location where the phone is?

What you see is the IP that the phone was seen and the port that the phone wants the UCM to use.


Phone is local to the UCM
SIP server on the phone is the IP address (same LAN/IP scheme) of the UCM

It seems to have spontaneously resolved. Rebooting both the UCM and the phone didn’t fix it. Then I went back to close the window 20 - 30 minutes later and saw that it was listing the correct IP address and port. Very odd.

Whether the phone is now working remains to be seen, client will test it tomorrow.

Problem is, if it spontaneously resolved, it can spontaneously un-resolve. :frowning:


Unless the local Lan is not in the UCM NAT setting and there is no remote softphone or other and nthing listed in the phone’s NAT IP setting or STUN is set… I have nothing.


Someone playing God with the patch cables and connected the voice and data network together providing a second DHCP server to the network perhaps ???


The local LAN address is in the NAT settings on the UCM
NAT and STUN are both disabled (and empty) in the phone settings
There are two remote phones in two different locations - but they are connecting fine and working

I’ll let you know if I figure it out - but for now it looks like it has resolved, we’ll see for how long.


I told them they would perish in eternal hellfire if they ever touched the patch cables. :smiling_imp:

More seriously - in this small office the voice and data networks are one and the same.

It’s just very odd that the phone system thinks the phone is connecting from the router/gateway.


I had a case today where a customer had run out of ports and decided to plug into a lan port of a device that offered IP addresses via DHCP and was on a different network… couldnt work out why till this morning when I went to site to isolate and found out that they had inadvertently plugged into a HT814… they were ringing me saying they couldnt connect up to their new machine via the local network…

Wrong network is why…


Interesting, thanks. Hadn’t occurred to me that someone might plug into the LAN port on the UCM. However that isn’t the issue in this case - the office LAN has a unique IP scheme, not your normal 192.168.x.x scheme that most DHCP capable devices hand out by default.