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New Member

CM 4.1(3) via Q.Sig to Siemens IsDX


I have been trying to integrate a CM 4.1(3)sr3a to a Siemens IsDX network of PBXs with Q.Sig.

We tried using Westell iIQ2000+ converters to allow CM to talk ISO Q.Sig to the Siemens which talks DPNSS to the Westell. This works fine for most functions including park, transfer, conference, etc. except for two problems:

1) When CM phone A calls Siemens phone B which is forwarded to another phone on the same Siemens switch, this works fine. But when the Siemens phone is forwarded to another phone on a different Siemens node in the Siemens network, the IP phone gets engaged tone.

When running debug isdn q931 the MGCP/Q.Sig gateway shows "Unknown / Unallocated number" as the cause code for the failure.

I have tried enabling forward by reroute and path replacement, but to no avail. Any suggestions?


Call back initiated from Cisco phone when Siemens phone is engaged. This works fine the other direction but not on CM, which shows for example "Callback cannot ba activated on extension 51190".

Anyone know if this is supported?

Thanks in advance for any response!!!


New Member

Re: CM 4.1(3) via Q.Sig to Siemens IsDX

Further developments with this:

I have found some material from Westell indicating the required settings on CM for the CallBack and Call Forwarding scenarios:

For the Call forwarding matter, Westell does say that you need to enable Call Forward by Re-Route. I've tried this to no avail, but am also waiting for the customer to re-start CM services to check out the Path Replacement settings that I implemented.

I'll post the results here when known.

CallBack (when free) initiated from CM, to the Siemens IsDX requires that you set Connection Response Type service parameter to default to "Connection Release".

I have not had a chance to test this yet, still waiting for the customer to restart SM services... I'll post the results here then.

If anyone knows more about this specific integration scenario, I'd really like to know.


Re: CM 4.1(3) via Q.Sig to Siemens IsDX


Your point 2) should not work anyway - it is a limitation of the Westel product specified in their Test Document. Anyway it was about half a year ago.



New Member

Re: CM 4.1(3) via Q.Sig to Siemens IsDX

Q1 sounds similar to a problem I recently had, in our case Phone A on CCM dialled phone B on MD110 (Via Qsig/westell/DPNSS).

Phone B was on divert to phone c on another PBX.

The problem was caused by DPNSS/PBX passing the extn number of Phone C back to CCM which did not have a valid route pattern for Phone C.

The CCM extns were all 8xxxx, the first MD110 had extns 4xxx and the 2nd MD110 had extns 5xxx but CCM had no route pattern to match the 5xxx numbers and hence dint know where to place the call


New Member

Re: CM 4.1(3) via Q.Sig to Siemens IsDX


Sorry, just noticed how old the original post was !

Hall of Fame Super Gold

Re: CM 4.1(3) via Q.Sig to Siemens IsDX

No worries, it's good info anyway - thanks !