Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

Unity configuration on CUCM


In my call manager configuration, I have the following setup:

Cisco Voice Mail Port, ports name CiscoUM1-VI1 to CiscoUM1-VI16 have calling search space 440_National_CSS attached to them.

Voice Mail Pilots configuration, I have Voice Mail Pilot Number 1000 configured with Calling Search Space 440_Internal_CSS.

My question is, when the a voice line in the unity server tries to reach a desk phone, which calling search space it will use, 440_National_CSS or 440_Internal_CSS?


Hall of Fame Super Red

Re: Unity configuration on CUCM

Hi Yao,

Should be 440_National_CSS

The CSS assigned to the VM-Ports.



New Member

Re: Unity configuration on CUCM

Thanks for your reply. Can you let me know what is the use of Calling Search Space assigned to Voice Mail Pilot Number 1000?

Hall of Fame Super Red

Re: Unity configuration on CUCM

Hey Yao,

If you follow the Integration guide properly (example below) you will

have a setup where phones can only dial the Pilot# and not the actual

Ports directly and all Incoming communication is done via the VM-Pilot.

This prevents the VM-Ports from being tied up via misdials

or accessed eroneously. This is done by using the Partition/CSS model

as described;

Setting Up a Cisco Unified Communications Manager 6.x SCCP Integration with Cisco Unity Connection

If you let us know your exact version of Unity/Unity Connection and CUCM we can get you the

proper documentation

Hope this  helps!


New Member

Re: Unity configuration on CUCM


This is a good question and has been bothering me too. Is there a good source of information on the exact, detailed call flow for calls to/from UCX for message retrieval/call forwarding to leave messages/mwi on-off calls, including the precise partitions and CSS's used each step of the way? I have looked pretty rigorously, and haven't been able to find anything. Every time I see this explained it seems a little bit different. Similarly, are there any books available/in the pipeline for UCX now that it is an important topic for the CCIE Voice test?

Here are some of my questions, based on the doc referenced in this thread for integrating CUCM/UCX. I don't have access to a CUCM/UCX integration to test right now. I have gotten integrations working in the past pretty easily, but I think I am missing a subtle but important piece of "how things work" so any assistance would be appreciated.

(I don't mean to hijack this thread, so let me know if I should move it so this one can be closed, if appropriate).

Regarding Yao's question, from the document it says:

To Add a Voice Mail Pilot Number for the Voice Mail Ports

CSS; "Click the calling search space that includes partitions containing the user phones and the partition you set up for the voice mail pilot number"

I understand the need for the partition with the VM Pilot Number (which is really the partition of the Hunt Pilot number as mentioned below, and which provides the protection noted in the response), but why does the VM Pilot Number CSS need to contain partitions for the user phones? When would the VM Pilot number need to place a call a "user" phone? Doesn't it only point to the Hunt Pilot, ever?

Some other questions:

1) To Add Partitions and a Calling Search Space to Contain the Voice Mail Ports

Step 6

Relatively minor nit, here.

When they say "For example, enter "VMPilotNumberPT, Partition for the voice mail pilot number" really it is for the partitition for the Hunt Pilot that the VM Pilot points to, since the VMPilot Number itself does not have a partition field. Just confusing wording since the Hunt Pilot and VM Pilot are the same number, I think. This is actually important when we put the partition with the Hunt Pilot into the CSS of the phone.

2) Regarding the CSS at both the VM Port (Device) and VM Port DN (Line) level, are there any best practices for designing these, particularly with regard to integrating with the overall dialplan design approaches for class of service (Traditional vs Line/Device). Or are they completely orthogonal?

Voice Mail Device Information Page

Table 6-2


"This calling search space must include partitions that contain all devices Cisco Unity Connection needs to access (for example, during call transfers, message notifications, and MWI activations). "

Makes sense. But just to clarify, the transfers they refer to in this context are not for calls to the Auto Attendant on UCX, which would use the CTI Route Point and associated DN CSS's. The transfers mentioned here would be for things like caller input actions of "transfer to alternate extension number" during a caller greeting. So even ports configured as "Answering Ports" might be placing outbound calls for things like transfer and therefore need a CSS. Is this correct?


Table 6-3 Settings for the Cisco Voice Mail Directory Numbers Page

CSS: "Click the name of a calling search space that you set up to contain the partition with all voice mail port directory numbers"

Why do the voice mail port DN CSS's point to the other VM Port DN's? Doesn't the Hunt List Line Group config cover the hunting functionality? What is this used for?

In terms of the Line/Device question above, it appears that the best practice is:

Dev CSS = communicate with UCM

Line CSS = point to other VM Port DNs, something to do with hunting?


Another minor nit.

Internal Caller ID Display:

"This text appears on the phone when the pilot number is dialed. "

Doesn't the description apply to the Alerting Name? Would the Internal CLID be used to appear on the phone for something like a transfer from a caller's greeting?

5) Table 6-8 and 6-9 MWI DN's

a) Why are they put in the same partition as the VMPilot, which is included in the Phone CSS?  Doesn't this give the phone the ability to call the mwi on/off numbers directly, which I believe is not desired?

b) What are the MWI DN CSS's used for? I have always thought they were used in kind of a two-step process, where CUCM receives the inbound call say to the mwi on number, and then uses the MWI on number css to place the call to the phone to activate the light, so the DN of the phone must be in the CSS of the MWI DN, as they state here. Is this correct? What confuses me is that the voice port already has the partitions with the phone DN's in its CSS, so that is what leads me to think it is a two-step process. Am I even close on this one?

Thanks for any help.


CreatePlease to create content