Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html

Published

2025-08-22

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

Cisco documentation terms of use; no-redistribution; short excerpts and locators only

Source notes citing this source

• The Unity Connection Check Telephony Configuration test does not test IPv6 connectivity; it confirms IPv4 communication with the phone system only. in context
• Too few ports assigned to send MWI requests can delay MWIs; Cisco directs administrators to the Port Activity Report in Cisco Unity Connection Serviceability Reports to evaluate this. in context
• Running MWI synchronization for a phone system integration can delay MWIs for new messages because of the additional MWI requests being processed. in context
• Cisco places enabling MWI macro traces as the last step of the 'MWIs Do Not Turn On or Off' procedure, after the configuration checks and a check for a recent upgrade, restore or disruption; the chapter itself does not name individual trace components. in context
• For the symptom 'No Message Count Sent on Phone When MWI is On', message counts are controlled per user under Playback Message Settings (Message Count Totals, Voice, Email, Fax and Receipt Message Counts). in context
• When MWIs are synchronized, Unity Connection queries its message store to determine the MWI status for all phones and resets the applicable MWIs. in context
• Cisco warns that synchronizing MWIs for a phone system may affect system performance and recommends doing it when phone traffic is light. in context
• Cisco recommends resynchronizing MWIs after a Unity Connection server is restored with the Disaster Recovery System, after upgrading, and after a WAN outage in a system that has distributed voice messaging through SRST routers. in context
• A Unity Connection MWI stays on when more messages are waiting to be heard or when the user marks a listened-to message as unread. in context
• When a message for a user arrives in the Cisco Unity Connection message store, Unity Connection notifies the phone system to turn on that user's MWI. in context
• Unity Connection lists a user saving or deleting a read message, and a user deleting a new message without listening to it, as triggers for updating the MWI. in context
• MWI synchronization is itself one of the documented triggers for Unity Connection to turn MWIs on or off. in context
• For Cisco Unified CM SCCP integrations only, the dial plan must not contain patterns that overlap the MWI extensions. in context
• For Cisco Unified CM SCCP integrations only, the MWI On and Off extensions must be in the same calling search space as the phones and voicemail ports. in context
• MWIs for a phone system are resynchronized from Telephony Integrations > Phone System by selecting Run for Synchronize All MWIs, which may affect performance and is best done in light traffic. in context
• The extensions that turn MWIs on and off must be in the same calling search space that contains the phones and the voice mail ports. in context
• The MWI On Extension and MWI Off Extension on the Unity Connection SCCP port group must match the Message Waiting numbers configured in Cisco Unified CM. in context

Cite this source record

APA

WarmTransfer. (2025, August 22). Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs). WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-cuc15-tsg-mwi

BibTeX

@misc{warmtransfer-cisco-cuc15-tsg-mwi,
  title  = {Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)},
  author = {{WarmTransfer}},
  year   = {2025},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-cuc15-tsg-mwi},
  note   = {Cisco Systems, accessed 2026-09-25}
}