Cisco Unity Connection and MWI ON/OFF

When integrating Cisco Unity Connection and Cisco Unified Communication Manager to provide the voicemail solution for users, Message Waiting Indicator (MWI). So whenever someone deposits a voicemail to the user, red light on the IP Phone’s handset will be turned on or a message envelope icon will be displayed on the IP Phone’s screen. Whenever that message is read by the user, the light will be turned off automatically or the message envelope icon will hide. In short. MWI is required in order to notify the user that they had missed a call while they were busy or away and the caller has left a voicemail message.CUC is connected to CUCM through two skinny based ports, they need to be able to dial the MWI, so the ports from the CUCM s perspective, has to have a CSS CSS-Port that can reach the partition of MWI Port-PT.
The phone has its own partition for 1001 Internal-PT, the MWI actually has CSS MWI-CSS and it needs to be able to see that partition Internal-PT.

The unity connection is going to send a Skinny call over the port and the call contains two important informations ANI for calling party and DNIS for called party.
The DNIS is the MWI 1899 , let’s say MWI ON.
But the CUC spoofs the ANI and says the person that called you, is 1001, The mwi things the call comes from 1001 and it tuns on the MWI.
The CSS of port can dial out to the phone directly or out to the PSTN through a transfer rules defined on CUC. So the port CSS needs to have the Partition of the DN 1001 and also the partiton of the route pattern that routes the call to the PSTN.

Published by:

Redouane MEDDANE

Redouane MEDDANE is Cisco Instructor CCSI #35458, 3xCCNP Collaboration, Security and Enterprise and he a published author of some of the most important OSPF Protocol, Security and Collaboration books in the world titled OSPF Demystified With RFC, Network Security All-in-one, and Dial Plan and Call Routing Demystified on CUCM. He is also a blogger at and writes articles about collaboration and security to demystify the most complex topics. His books are known for their technical depth and accuracy especially the OSPF Demystified With RFC book, which is considered as the best OSPF book in the world and named "One of the best OSPF ebooks of all time" by BookAuthority It gives you a hint at the ability to explain complex topics with remarkable ease. He worked as a Cisco Instructor and consultant indifferent Cisco Learning Partner and awarded twice as Cisco Distinguished Instructor Award and Cisco Security Instructor Excellence Award on 2018 and 2019, and Cisco Collaboration Instructor Excellence Award on 2020. The Distinguished Instructor Award recognizes the top 5% of Cisco's most influential CCSI's who provide the highest quality training experience and demonstrate the best overall instructor performance across multiple Cisco technologie and Instructor Excellence Award recognizes the top 25% of elite CCSIs being recognized for delivering top quality training and maintaining high customer satisfaction in their field of expertise.

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