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Requirement to Interrupt User while on call


i have CUCM 6.X and we are looking at a feature to interrupt a user while they are on a call. example, if user A is on a call (PSTN or Internal) and thier manager sees thier BLF as on a call but need to speak to them urgently, they should be able to call them, automatically put the other user on hold and then speak to intended user. basically, im assuming barge in on the call.

No shared line etc will be used and this isnt a contact centre environment.

any assistance would be appreciated.

VIP Super Bronze

Re: Requirement to Interrupt User while on call

That's not going to happen. The agent will see the caller alerting and they can answer or ignore it as normal. If it is urgent, the supervisor should use the chat function within CAD to get the agent's attention.

Also, be careful if this is a contact center, (at least for express - I can't speak to enterprise): The busy trigger should be set to one (1) on the ICD DN. The supervisor would get a busy signal if they attempt to dial that line while the agent is on a call.


Re: Requirement to Interrupt User while on call

got it but this isnt a contact centre environment at all. Just call manager 6.X but we are looking for that feature. Note that it doesnt have to be native (i didnt expect it to be native) to the call manager at all, a third party app should be able to work. im almost certain that they should have some type of solution for this. hummm.

VIP Super Bronze

Re: Requirement to Interrupt User while on call


I should have been a little more measured in my response. When I read "contact center" my mind jumped to the restrictions imposed by it. If you are using just UC Manager then MLPP will definitively work. I hadn't considered Intercom but that's another good idea.

Note that, at least with Contact Center Express, MLPP is not supported. If you are going that route you may want to choose carefully before deploying.

For reference in case you need it:

Multilevel precedence and preemption (MLPP).

You can enable this feature for devices in the cluster that do not interact with

Cisco Unified CCX.

Re: Requirement to Interrupt User while on call

What you are looking for is Multilevel Precedence and Preemption (MLPP). I have never set it up, but it is designed to do exactly what you are looking for. Check out this link:

Although I think, if I remember correctly, it disconnects the original caller (after a brief warning) rather than places them on hold.

Re: Requirement to Interrupt User while on call

I set up MLPP for this reason a couple of months ago for a system that was deployed on a ship.

It does not barge into the call immediately - the called party hears a special ringing tone but can continue to talk to the other party for 30 seconds after which time the call is dropped and the MLPP caller connected.

I set MLPP to be invoked by dialling * followed by the extension. There are four (IIRC) MLPP precedence levels which can pre-empt each other but it sounds like you can get away with one.

It works ok - it is not an instant barge but in some ways that is good because it allows the called party to quickly wrap up their call.

The period of 30 seconds before dropping the original call is fixed and cannot be altered with Service/Enterprise parameters.

One gotcha is that the busy trigger on the line of the called party needs to be set to one (rather than the default two) for MLPP to work correctly.

Please rate if helpful.


Re: Requirement to Interrupt User while on call

Guys a million thanks as usual. The diconnection of the original caller is kind of too rude but its up to the customer to decide. im going to set this up and see how it works.

thanks once again

Re: Requirement to Interrupt User while on call

If CME works for you, you may be interested in the 'whisper intercom' feature.




Re: Requirement to Interrupt User while on call

EXACTLY what im looking for....but on CUCM.....i always wonder why standard things on CME isnt standard on CUCM? i suppose thats another topic all in itself.

Re: Requirement to Interrupt User while on call

This exists in CUCM but the implementation is different:

Intercom allows a user to place a call to a predefined target. The called destination auto-answers the call in speakerphone mode with mute activated. This sets up a one-way voice path between the initiator and the destination, so the initiator can deliver a short message, regardless of whether the called party is busy or idle.

To ensure that the voice of the called party does not get sent back to the caller when the intercom call is automatically answered, Cisco Unified Communications Manager implements whisper intercom. Whisper intercom means that only one-way audio exists from the caller to the called party. The called party must manually press a key to talk to the caller.

To use the intercom feature, both the caller and called phones require a dedicated intercom line button. This line will have its own Directory Number (DN), which is its intercom code, and partition (intercom group). The Calling Search Space for this intercom line gets used to restrict the access of intercom destination from this phone.

he system does not allow an intercom line to be shared on multiple devices. It should not have any other feature-related configuration, such as forward, pickup, voice mail profile, and so on.


It sounds like if you create a 1-to-1 mapping on the phone this may work for you.




Re: Requirement to Interrupt User while on call

Great response there. based on the question i had from the customer it seems as though they want to be a little more intrusive than what is mentioned below.

"The called party must manually press a key to talk to the caller"

the initial request came about where a manager was trying to call an employee but he was on the phone and it was something seems as though the employee was ignoring the call and they wanted a way to call the employee , tell him what he needs to hear :) and then hangup, all the while the person at the other end is hearing music or whatever..hehe. i know it sounds something you might want to not really want to do but still

Hall of Fame Super Red

Re: Requirement to Interrupt User while on call

Hey Arvind,

Hope all is well my friend! Just to add a note here to go along with the great tips from Nick. This actually does do exactly what the manager wants :)

Scenario 3

Anna, while on a connected or held call, receives an intercom call from Gerald, the preconfigured intercom target

While Anna is speaking on the phone, the preconfigured intercom line indicator flashes amber, which indicates that Gerald is calling Anna on the intercom line.

-The line key displays solid green.

-The intercom key displays solid amber.


Note When Auto Line Select is disabled, which represents the default, the current call retains focus.


•The phone that Anna is using plays an auto-answer alert tone, followed by the voice of Gerald.

•Anna can hear Gerald, but Gerald cannot hear Anna until she addresses the intercom call.

•The current caller, who is at 9873 and is on the line with Anna, can hear Anna but cannot hear Gerald.

Hope this helps!



Re: Requirement to Interrupt User while on call

Rob its been a while, things are good. thanks for the input, im doing it up in the lab right now. thanks again everyone.

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