One extension is randomly busy?!

Hey all,

I have a strange problem. I have three extensions in a ringroup set to “ringall.” 80% of the time it works fine, but on occasion, only two of the extensions ring. The log shows the following:

== Using SIP RTP TOS bits 184
== Using SIP RTP CoS mark 5
– Called 102
== Using SIP RTP TOS bits 184
== Using SIP RTP CoS mark 5
– Called 101
== Using SIP RTP TOS bits 184
== Using SIP RTP CoS mark 5
– Called 110
– Started music on hold, class ‘default’, on SIP/voipms-0000044e
– SIP/110-00000451 is ringing
– SIP/102-0000044f is ringing
– Got SIP response 486 “Busy Here” back from
– SIP/101-00000450 is busy
– SIP/102-0000044f answered SIP/voipms-0000044e
– Executing [[email protected]:1] Set(“SIP/102-0000044f”, “__MACRO_RESULT=”) in new stack
– Executing [[email protected]:2] NoOp(“SIP/102-0000044f”, “Deleting: BLKVM/100/SIP/voipms-0000044e TRUE”) in new stack
– Stopped music on hold on SIP/voipms-0000044e

It is extension 101 I am worried about. This is the only extension with voicemail (don’t know if that’s important). I switched the physical phone out, thinking that might be an issue, but the problem persists. Can anyone give me an idea of how to proceed debugging this?


PS, I understand that the line is reported as busy, but no one is on the phone. There is no reason the line should be busy.

I am still experiencing this problem… its like a ghost on the phone. Does anyone have any ideas? Anything… even just an idea on posting more from the log file… its kind of driving me crazy =(.

It’s not a phantom busy, whatever device is attached to sent that response.

Got SIP response 486 "Busy Here" back from

What kind of phone is it? Could the user be bumping DND?

Thanks Skying, it is undoubtedly the device, Cicsco 303. I looked at the phones config and noticed that there were some odd discrepancies. I reset the phone and reconfigured from scratch and now things seems to be working properly. I am not clear on what the problem was: I had two lines setup on the phone, Line 1 using port 5060 and line 2 using port 5061 (unnecessarily I assume). Both lines were, of course, assigned to different extensions and, as a remnant of my initial experimentation (total noob here) I had one line set to require registration and the other set to answer and make calls without it. I now have only one line configured on the phone on port 5060 without requiring registration, and things seem to be fine. On a separate note, do you happen to have any resources handy for getting FreePBX to discover Cisco 303s as endpoints? I have been unsuccessful so far.

I don’t know what “discover as an end point” means.

All the SPA series phone use a similar config so a template could easily be created in the endpoint manager.