No ringing tone on some outgoing calls

[dutch_tuga]

Hi all,

we have a MiCollab system that when the costumer dials out from the Mitel to some numbers they don't hear anything until the other side answer the call. This seems to happen when when the Mitel gets a 183 (session progress). When the Mitel receives a 180 (ringing) then the caller hears the ringing tone.

This applies to international numbers and they had experienced the same with toll free numbers. We have turned the option  "Ignore SDP Answers in Provisional Responses" to yes and they are able to hear ringing tone on toll free numbers. But international calls in the example. They still do not hear anything.

Does someone has experienced this before and know a solution/workaround.

Many thanks.

[petr.necas]

I would try set the "Disable Reliable Provisional Responses" to Yes.

[dutch_tuga]

This option was already enabled.

[petr.necas]

I was experiencing with this a little, on our MCD 8.0 with the "Disable Reliable Provisional Responses" set to Yes I could start hearing ringtone as soon as the first Session Progress packet arrives.

What SW version do you have?

[dutch_tuga]

The current version the system is running on is 7.2.1.13

[petr.necas]

This looks to be a version of MiCollab, what MCD version do you have?

[dutch_tuga]

That is correct. The MCD version is 7.2 SP1 PR1

[dutch_tuga]

Just as an update this has been fixed. We received another registration SIP server from the provider side. No more issues since then.