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New Member

MWI slow to light

Hi, our customer has Unity 3.0 unified messaging using a seperate Exchange 2000 email system as the message store.

They are experiencing variable delay in MWI lighting. Message arrives in the inbox within 5 seconds, MWI can take up to 30 mins. Sometimes it doesn't light at all.

There is also a delay in the MWI going off after message is read.

Any ideas anyone?


Re: MWI slow to light

Sounds like things aren't well. There is no easy fix for MWI issues. You should start troubleshooting with this URL:


Cisco Employee

Re: MWI slow to light

New Member

Re: MWI slow to light

I've looked at this tech note. AppleTalk has never been configured.

Any other reasons why this would happen?

New Member

Re: MWI slow to light

I have one tip to try- I always turn off Dial Out MWI on all of my ports except one or two, and I make those the last ports. That way the MWI does not get blocked out by calls coming in. I also do the same with message notification.

Go to config-->Ports-->uncheck DialOut MWI for all but the last couple of ports.

for a 4 port system I will only use 1, for a 24 port system i will use 4.


New Member

Re: MWI slow to light

I have encountered similar problems in a Unity installation in South Africa. In this scenarion a single Unity server connects to two call managers, one in Johannesburg and one in Pretoria. The Unity server is connected to the same switch as the Johannesburg CM.

MWI in Johannesburg works fine, but MWI in Pretoria is delayed by approx 6 minutes. Checking the message qeueuing logs shows that Unity registers the fact that a new message has been left for a Pretoria user straight away, and attempts to set the MWI. However, it consistently sends it out of the wrong port. Eventually it sends it via the correct port and the MWI is set.

It seems in dual CM integration there is no way of associating which ports should be used for which set of extensions - consequently Unity tries to blast it out of the last port in a range, regardless of whether it is the correct range or not...

The issue is still not resolved.

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