We have a problem where an certain IP Phones (4 of them in one department) periodically lose dial-tone.
Incoming calls can be received but transfer or outbound calls do not work.
Picking up the handset activates the line (the icon changes to off-hook) and it lets you type in the number to dial then says 'ringing' but nothing happens at the other end.
Three of the four phones are part of a ephone-hunt group while the 4th phone WAS part of the huntgroup but was removed.
They are all part of the same pickup group.
No other phones exhibit the same issues - there are 120 handsets connected to this CME config in total and the problem occurs daily on at least one of those four handsets.
There is a basic IVR which transfers to the hunt group pilot.
Resetting the IP phone resolves the issue.
IOS image: c3900-universalk9-mz.SPA.151-3.T1.bin
CUCME Version: 8.5
Debugs have shown the below message but everything else appears OK. Phone and line status show 'idle' for both channels and there's no obvious change from when the phone is functioning correctly.
086853: May 22 07:19:27.302: efxs_onhook_offhook: call is already reserved on htsp 50/0/279.1 cdb 0x0
50/0/279 1 efxs up dorm on-hook idle y
50/0/279 2 efxs up dorm on-hook idle y
ephone output while phone is not receiving dial-tone:
ephone-279 Mac:64AE.0CF6.9CEF TCP socket: activeLine:0 whisperLine:0 REGISTERED in SCCP ver 20/17 max_streams=5
mediaActive:0 whisper_mediaActive:0 startMedia:0 offhook:0 ringing:0 reset:0 reset_sent:0 paging 0 debug:0 caps:9
IP:192.168.10.171 * 50686 7942 keepalive 524 max_line 2 available_line 2
using default button layout
button-layout 1: line button 1: cw:1 ccw:(0 0)
dn 279 number 279 CH1 IDLE CH2 IDLE
Preferred Codec: g711ulaw
Lpcor Type: none Username: spare Password:
Cisco TAC is looking at it, but does anyone have any ideas?
Our issue seemed to be triggered by GPickup / Pickup of a call from a hunt group.
We had a TAC case going for about 2 months to try and resolve it (numerous debugs/packet captures etc) but the issue didn't occur every time, only once or twice per day out of 4 phones taking calls all day.
TAC weren't able to reproduce it in the lab and the developers created some patches but lab testing showed they introduced other issues (according to the TAC engineers) so we never applied them.
Eventually we gave up...
Sorry I don't have a fix for you.