MWI not working on 7911 IP Phones

[rv_viji]

We have recently installed the cisco unity 5.0 and integrated with exchange 2007 and our CUCM 6.1

The MWI is not working on 7911 IP Phones only for the messages received from the users (phones) who have subscriber account in the unity server, however MWI is working perfectly fine for the messages received from users (phones) who does not have subscriber account in unity server and also for messages from outside callers its working fine...

Also note, when the users(phones) who has got subscriber account in unity leaves VM, the email can be seen on the exchange inbox, but MWI will not be ON and also if the msgs button is pressed the system says you do not have new messages..

However we have other IP phone models like 7941G-GE, 7961G-GE, 7971G-GE... in these phones there is no issue at all, irrespective of whether the users (phones) have subscriber account or not the MWI is working perfectly fine...

So any idea what could be the issue??

[MMstre]

Are the 7911 phones using the same voicemail profile?

[rv_viji]

yes..

[MMstre]

Try dialing the MWI extension from the phones and see if they respond by illuminating their lights.

[rv_viji]

Yes, its working fine... if I dial the MWI ON number the light glows and dial the MWI OFF it goes OFF...

Also as I had mentioned the MWI is perfectly fine if the VM is from the users (phones) who do not have subscriber account and also from outside callers (PSTN calls coming through my VG)...

[rv_viji]

can someone give me any inputs about what could be the issue??