Using ISDN feature "Partial Rerouting" for correct displaying of calling party in forwarded calls

[Tadeusz Zeludziewicz]

Hello,

We have CUCM 9.1 with MGCP gateways + ISDN trunks,

I'm looking for a solution for correct displaying of calling party in forwarded calls ...

At present, when an incoming PSTN call is forwarded, what is displayed at the destination is our root PSTN number > no way to see who was calling. The operator has suggested to use Partial Rerouting, but apparently this needs also some configuration on the CUCM side.

Has anyone any experience with this, or another solution to the problem ?

[Jitender Bhandari]

Hi

see if below service parameter helps

Retain Forward Information:	This parameter determines whether forwarding information displays to the called party after the party goes off-hook. When enabled, this parameter also ensures that the forwarding information continues to be displayed on the called party's phone while the phone is ringing, even if the calling party information is updated during that time. Valid values specify True (display forward information) or False (do not display forward information).
	This is a required field.
	Default:  False

JB

[Yorick Petey]

Hello Tadeusz,

I know the discussion was 4 years ago, but by chance did you succeed to enable Partial Rerouting with Cisco UCM and the telco?

Thank you.

[TONY SMITH]

On ISDN it's going to depend on what the carrier accepts.  For example in the UK an ISDN will normally only accept a calling number matching either the main billing number or one of the DDIs routing into that ISDN.  Any other number will be rejected as invalid and replaced with the billing number.

Your carrier may either permit other numbers, or offer an option to do so.  This will be carrier specific and they may also set requirements for the Type of Number and Plan settings as well as the exact format they want to see the number.

[Yorick Petey]

Hello Tony,

Thanks for your answer. Here in Luxembourg, the main provider usually enables the "CLIP no screening" feature per request, allowing the PBX to send any value as Calling Number. The thing here, that time they cannot activate this feature because the ISDN PRI is a bit special and not "compatible" with this feature. Instead, they propose the Partial Rerouting feature.

Based on my findings, it appears that Partial Rerouting (also known as Path Replacement) is supported by CUCM but only when using QSIG. And the provider doesn't enable QSIG on the public lines. So I guess we are stuck.