Unity to QSIG MWI

[KeithFrench]

If you have Unity with Message Waiting Idicator going to a PBX phone that is served via a Q.SIG link from an MGCP gateway on CCM V4.1, how is MWI handled in Q.SIG?

From CCM V4.1 MWI is handled correctly within Q.Sig rather than using DNs to turn it on or off.

Is seems to be carried as a facility message within the setup packet called "Invoke ID"? When you look at a trace of the Q.Sig in a Trend Duet it seems to show Invoke ID = 0807 to turn MWI on. To turn it off again it seems to set Invoke ID = 0808.

Can anyone confirm this and or point to a reference on the net for the values of Invoke ID?

 

[jneiberger]

http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-242.pdf

That should have more about QSIG MWI than you ever wanted to know.

 

[KeithFrench]

Thanks for this PDF, it is indeed comprehensive. However, it still doesn't seem to mention the Q.Sig Facility Element "Invoke ID" and the two values I have seen (0807 & 0808).

 

[jneiberger]

To add to the confusion, everything I can find on Invoke IDs indicates that they are one byte in length. I wonder if what is being mentioned as an Invoke ID in your debug output is actually that Invoke ID plus some other parameter? If so, then perhaps we should be looking for information about the second parameter.

I'll let you know if I run across something.

 

[jneiberger]

Okay, I've made a little progress. The first byte appears to be the Invoke ID and the second byte indicates the operation being performed. I haven't found anything specific to MWI, though.

 

[KeithFrench]

Thanks again for your efforts, so to recap the first 08 identifies that it is Invoke ID and the second 07 or 08 is the parameter?

 

[jneiberger]

That's what it looks like to me but I'm having a hard time finding good resources that discuss this topic. I thought for sure the ECMA site would have this info but I haven't found it yet.

 

[KeithFrench]

Thanks anyway for your efforts.

Keith.