SIP Phones No Ringback 1

[OldTimingMan]

Mitel SIP support is stumped so far.

Telematrix 9602IP phones. Mivoice Biz 7.2. Wireshark shows called phone sends 180 / sdp to pbx but pbx does not send it to caller. Call can be completed by answering called phone, which actually rings.

I have followed guidelines in SIP CoE 10-5159-00058 to the letter. CETIs SIP support pointed out the SDP issue.

Anyone? Help......

 

[Billz66]

is this for MiVB ext->telematrix and trunk calls -> telematrix?

i had a similar issue the other day with some sip trunks and had to change the only use SDP for 180 183 from yes to no on the sip peer

my problem was external sip trunk into Mivb - across xnet to 2nd mivb out E1 to alcatel system

calls to alcatel ext had no ringback until i made the change


If I never did anything I'd never done before , I'd never do anything.....

 

[OldTimingMan]

This issue is internal calls only. Thanks

 

[mhawk]

Can you post the SIP device capabilities ?
It's not in the interop doc, But I would try setting "Force sending SDP in initial Invite message" to Yes

And if there is no MBG in the mix
"Enable Mitel Proprietary SDP" to No

This has resolved similar issues for me with SIP trunks, I've never had the ring back issue internally between stations.

 

[OldTimingMan]

mhawk, thanks. Did not correct the issue.
Tried reset on pbx tonight; no change.

 

[mhawk]

What MCD version are you running ?
Can you post the SIP Device capabilities in full ?

What is the "Ignore SDP Answers in Provisional Responses"

I haven't tested this one myself but the docs say "improves interoperability with systems that use RFC 3960. To avoid the possibility of no ringback tone on outgoing SIP trunk calls, the SDP Answer in 18x messages is ignored and the local ringback tone is provided to the device placing the call. This option is also added to the SIP Device Capabilities form."

You mention this is internal Set to Set dialing, Do they hear ringback when calling external ? What about calling to/from another type of set, Analog or Minet

 

[OldTimingMan]

See attachment.

Ignore SDP is NO. Support already had me change it to Yes.

The issue is whenever a SIP device is called, either from another SIP phone or from a Mitel device, there is no ringback tone. If a Mitel device is called or a trunk is used from a SIP phone, I hear ringback tone.

 

[mhawk]

Seems like you have been through the common causes already with support.

What version of MCD are you running ? You may have found some sort of bug.
Unfortunately the interop doc hasn't been updated since MCD 5.0

Definitely grasping at straws a bit here.... But it looks like the telematrix phones have configurable SIP RFC versions.

For lack of any better options you could try changing this setting to see if it behaves differently.
My thinking is that if this is some sort of bug, reverting back to the older "SIP v1" might change the signaling between the phone and the MCD. This may setting may also have an adverse effect on other features....

RFC Protocol Edition: SIP versions are identified
by the IETF (Internet Engineering Task Force).
SIP version 1 is RFC 2543. The default is the
newer SIP 2 RFC 3261. An example of when
you might revert back to RFC2543 is if the gate
needs to communicate to older devices (such as
CISCO5300) using the SIP 1.0 (RFC2543 protocol).
Default is RFC 3261.

 

[OldTimingMan]

Thanks mhawk. I did try that on my own several days ago. Didn't work. When looking at the SIP trace, we can see 180- Ringing coming from the called extension to the PBX, but 180 is not sent to the calling phone by the PBX.

 

[OldTimingMan]

ISSUE RESOLVED by Mitel:

Require Reliable Provisional Responses on Outgoing Calls needs to be Disabled. Enabled is default and COE dox don't say to change it.

Thanks guys.