# Integrating Unity Connection with Unified CM

For Unified CM and Unity Connection administrators configuring voicemail integration.

Canonical: https://warmtransfer.net/guides/unity-connection-cucm-integration-setup

Last verified: 2026-09-25

Integrating Cisco Unity Connection with Cisco Unified Communications Manager (Unified CM) provides voicemail answering, personal greetings, and message-waiting indicators[^19]. In this deployment model, Unity Connection runs on a dedicated server separate from Unified CM[^43].

## Before you start

- Unified CM and Unity Connection must be installed on separate servers[^43].
- Review your Unity Connection licensing: the total number of messaging ports configured across all integrated Unified CM clusters cannot exceed the licensed port count[^33].
- See also [Unified CM dial plan partitions and calling search spaces](https://warmtransfer.net/knowledge/cucm-dial-plan) and [Message waiting indicator troubleshooting](https://warmtransfer.net/knowledge/mwi-troubleshooting).

## What changes by situation

- How will Unity Connection connect to Unified CM? SIP trunk; SCCP voice mail ports.
- Is Unity Connection one server or an active/active pair? One Unity Connection server; Unity Connection cluster (active/active pair).
- How many Unified CM clusters will use this Unity Connection? One Unified CM cluster; Two or more Unified CM clusters.

## Step 1: Plan port roles and multi-cluster capacity

**One Unified CM cluster**

### Do
- Check the total number of voice messaging ports enabled by your Unity Connection licenses[^33].
- Dedicate specific voice messaging ports to answering incoming calls and separate ports to outbound dialing tasks such as MWI, message notification, and TRAP connections[^31].
- Ensure no dial-out-only ports are configured to receive incoming user calls[^32].

### Verify
Suggested check: Verify that the planned sum of answering and dial-out ports does not exceed the total licensed port capacity.

### Rollback
Suggested rollback: Revise the planned port allocation.

**Two or more Unified CM clusters**

### Do
- Confirm that Unity Connection is not deployed as a co-resident Cisco Business Edition instance on the same server as Unified CM, as multiple integrations are not supported on that deployment[^25].
- Verify that directory numbers and extensions are unique across all connected Unified CM clusters and that dial plans do not overlap[^28].
- Sum the intended port counts across all clusters so that the combined total remains within the licensed Unity Connection port limit[^33].
- Dedicate specific ports within each cluster to answering incoming calls and separate ports to outbound operations[^31]. Ensure calls are never directed to ports not configured to answer[^32].

### Verify
Suggested check: Confirm that all cluster extension ranges are mutually exclusive and the summed port counts across all clusters fit within the licensed port capacity.

### Rollback
Suggested rollback: Adjust the planned multi-cluster port counts and dial plans.

## Step 2: Configure the telephony connection in Unified CM

**SIP trunk**

### Do
- Under System > Security > SIP Trunk Security Profile, create a security profile with Accept Out-of-Dialog REFER, Accept Unsolicited Notification, and Accept Replaces Header checked[^54][^62][^63].
- Under Device > Device Settings > SIP Profile, copy an existing profile, and ensure Enable ANAT is checked only if IPv6 or dual-stack is used[^49].
- Under Device > Trunk, create a SIP trunk to each Unity Connection server[^64].
- On each trunk, check Redirecting Diversion Header Delivery for both Inbound and Outbound[^45].
- Set Destination Address to the Unity Connection server IP address and keep the default destination port 5060[^44].
- Configure the trunk's inbound Calling Search Space, Rerouting Calling Search Space, and Out-of-Dialog Refer Calling Search Space to a CSS that reaches user phones[^50].

### Verify
Suggested check: Open the SIP trunk and confirm the assigned security profile has unsolicited notification enabled, diversion headers are enabled inbound and outbound, and the destination port matches configuration.

### Rollback
Suggested rollback: Delete the SIP trunk, followed by the SIP profile and SIP trunk security profile.

**SCCP voice mail ports**

### Do
- Create a partition for voicemail port directory numbers (for example, VMRestrictedPT) and a calling search space (for example, VMRestrictedCSS) that user phones do not use, preventing direct dialing to the ports[^41].
- Create a partition for the hunt pilot (for example, VMPilotNumberPT)[^41].
- Navigate to Advanced Features > Voice Mail > Cisco Voice Mail Port Wizard to create voicemail ports, entering a voicemail server name that matches the Device Name Prefix configured in Unity Connection[^42]. Assign the ports to the restricted partition and CSS[^41]. Keep the port count within license limits[^33].

### Verify
Suggested check: Verify that the voicemail port devices appear with device names starting with the configured prefix and directory numbers in the restricted partition.

### Rollback
Suggested rollback: Delete the voicemail port devices, port directory numbers, and restricted partitions and calling search spaces.

## Step 3: Configure pilot routing

**One Unity Connection server + One Unified CM cluster + SIP trunk**

### Do
- Under Call Routing > Route/Hunt > Route Pattern, create a route pattern matching the voice mail pilot number and select the Unity Connection SIP trunk as the gateway or route list[^53].

### Verify
Suggested check: Verify that the route pattern shows the Unity Connection SIP trunk as its gateway destination.

### Rollback
Suggested rollback: Delete the route pattern.

**One Unity Connection server + Two or more Unified CM clusters + SIP trunk**

### Do
- On each cluster, under Call Routing > Route/Hunt > Route Pattern, create a route pattern matching the cluster's voice mail pilot number and direct it to that cluster's SIP trunk pointing to the Unity Connection server[^53].

### Verify
Suggested check: Confirm on each cluster that the route pattern points to the correct SIP trunk.

### Rollback
Suggested rollback: Delete the route pattern from the respective cluster.

**Unity Connection cluster (active/active pair) + One Unified CM cluster + SIP trunk**

### Do
- Under Call Routing > Route/Hunt > Route Group, create a route group containing the SIP trunks to both Unity Connection servers[^51].
- Set the distribution algorithm to Top Down and place the subscriber server's trunk first[^51].
- Under Call Routing > Route/Hunt > Route List, create a route list containing this route group, save, and reset the route list[^52].
- Under Call Routing > Route/Hunt > Route Pattern, create the voice mail pilot route pattern[^53]. WarmTransfer's reading of the sources is that the voice mail pilot route pattern should target the route list rather than a single trunk, so calls reach the second server when the first is unavailable[^46].

### Verify
Suggested check: Confirm that the route group lists the subscriber trunk first with Top Down algorithm, and the route pattern points to the route list.

### Rollback
Suggested rollback: Delete the route pattern, then the route list, then the route group.

**Unity Connection cluster (active/active pair) + Two or more Unified CM clusters + SIP trunk**

### Do
- On each Unified CM cluster, under Call Routing > Route/Hunt > Route Group, create a route group containing the SIP trunks pointing to both Unity Connection cluster nodes[^51].
- Set the distribution algorithm to Top Down, listing the subscriber server's trunk first[^51].
- Under Call Routing > Route/Hunt > Route List, create a route list containing the route group, save, and reset it[^52].
- On each cluster, create the voice mail pilot route pattern under Call Routing > Route/Hunt > Route Pattern[^53]. WarmTransfer's reading of the sources is that the voice mail pilot route pattern should target the route list rather than a single trunk, so calls reach the second server when the first is unavailable[^46].

### Verify
Suggested check: Verify on each cluster that the route group lists the subscriber trunk first and the route pattern targets the route list.

### Rollback
Suggested rollback: Delete the route pattern, route list, and route group on each cluster.

**One Unity Connection server + One Unified CM cluster + SCCP voice mail ports**

### Do
- Under Call Routing > Route/Hunt > Line Group, create a line group containing only the voice mail ports dedicated to answering calls, ordered numerically[^37]. Do not include dial-out-only ports[^37][^32].
- Set the Distribution Algorithm to Longest Idle Time[^36].
- Under Call Routing > Route/Hunt > Hunt List, create a hunt list, check For Voice Mail Usage, add the answering line group, and reset the hunt list[^34].
- Under Call Routing > Route/Hunt > Hunt Pilot, create a hunt pilot in the pilot partition (such as VMPilotNumberPT) that routes to the hunt list[^35]. Ensure the hunt pilot number differs from all voicemail port extensions[^35].

### Verify
Suggested check: Verify that the line group contains only answering ports and that the hunt list has For Voice Mail Usage checked.

### Rollback
Suggested rollback: Delete the hunt pilot, hunt list, and line group.

**One Unity Connection server + Two or more Unified CM clusters + SCCP voice mail ports**

### Do
- On each Unified CM cluster, under Call Routing > Route/Hunt > Line Group, create a line group containing only answering ports for that cluster in numerical sequence[^37]. Exclude dial-out ports[^37][^32].
- Set the line group Distribution Algorithm to Longest Idle Time[^36].
- Under Call Routing > Route/Hunt > Hunt List, create a hunt list with For Voice Mail Usage checked, add the line group, and reset the hunt list[^34].
- Under Call Routing > Route/Hunt > Hunt Pilot, create a hunt pilot in the pilot partition pointing to the hunt list, with an extension distinct from all port extensions[^35].

### Verify
Suggested check: Confirm on each cluster that the hunt pilot points to the hunt list and only answering ports belong to the line group.

### Rollback
Suggested rollback: Delete the hunt pilot, hunt list, and line group on each cluster.

**Unity Connection cluster (active/active pair) + One Unified CM cluster + SCCP voice mail ports**

### Do
- Under Call Routing > Route/Hunt > Line Group, create a line group with only answering ports, ordered in numerical sequence[^37]. Exclude dial-out ports[^37][^32].
- Set the Distribution Algorithm to Top Down[^36].
- Under Call Routing > Route/Hunt > Hunt List, create a hunt list with For Voice Mail Usage checked, add the answering line group, and reset the hunt list[^34].
- Under Call Routing > Route/Hunt > Hunt Pilot, create a hunt pilot in the voice mail pilot partition that routes to the hunt list, with a number distinct from port extensions[^35].

### Verify
Suggested check: Verify that the line group distribution algorithm is Top Down and contains only answering ports.

### Rollback
Suggested rollback: Delete the hunt pilot, hunt list, and line group.

**Unity Connection cluster (active/active pair) + Two or more Unified CM clusters + SCCP voice mail ports**

### Do
- On each Unified CM cluster, create a line group under Call Routing > Route/Hunt > Line Group containing only answering ports in numerical order[^37]. Exclude dial-out-only ports[^37][^32].
- Set the Distribution Algorithm to Top Down[^36].
- Create a hunt list under Call Routing > Route/Hunt > Hunt List with For Voice Mail Usage checked, add the line group, and reset it[^34].
- Create a hunt pilot in the pilot partition pointing to the hunt list under Call Routing > Route/Hunt > Hunt Pilot, using an extension different from the voicemail ports[^35].

### Verify
Suggested check: Verify on each cluster that the line group algorithm is Top Down and the hunt list has voicemail usage selected.

### Rollback
Suggested rollback: Delete the hunt pilot, hunt list, and line group across each cluster.

## Step 4: Configure the message-waiting mechanism

**One Unity Connection server + One Unified CM cluster + SIP trunk**

### Do
- No dedicated MWI on/off directory numbers are required in Unified CM for a SIP integration[^64].
- WarmTransfer's reading of the sources is that MWI requests arrive over the SIP trunk as unsolicited notifications that the trunk security profile accepts[^47]. Confirm that Accept Unsolicited Notification remains checked on the SIP trunk security profile[^54][^65].

### Verify
Suggested check: Verify that the SIP trunk security profile has Accept Unsolicited Notification selected.

### Rollback
Suggested rollback: No configuration removal is needed.

**One Unity Connection server + Two or more Unified CM clusters + SIP trunk**

### Do
- Do not configure MWI directory numbers in Unified CM, as the SIP trunk integration removes the need to define directory numbers for MWI[^64].
- WarmTransfer's reading of the sources is that MWI requests arrive over the SIP trunk as unsolicited notifications[^47]. Ensure Accept Unsolicited Notification is enabled in the SIP trunk security profile across every cluster[^54][^65].

### Verify
Suggested check: Confirm that each cluster's SIP trunk security profile permits unsolicited notifications.

### Rollback
Suggested rollback: No configuration removal is needed.

**Unity Connection cluster (active/active pair) + One Unified CM cluster + SIP trunk**

### Do
- MWI directory numbers are not needed on Unified CM for a SIP integration[^64].
- WarmTransfer's reading of the sources is that MWI requests arrive over the trunk as unsolicited notifications[^47]. Ensure Accept Unsolicited Notification is checked on the SIP trunk security profile used by both trunks[^54][^65].

### Verify
Suggested check: Verify that the SIP trunk security profile has Accept Unsolicited Notification checked.

### Rollback
Suggested rollback: No configuration removal is needed.

**Unity Connection cluster (active/active pair) + Two or more Unified CM clusters + SIP trunk**

### Do
- MWI directory numbers are omitted across all clusters for a SIP integration[^64].
- WarmTransfer's reading of the sources is that MWI requests arrive over the trunk as unsolicited notifications[^47]. Confirm each cluster's SIP trunk security profile has Accept Unsolicited Notification enabled[^54][^65].

### Verify
Suggested check: Verify the security profile settings on all clusters.

### Rollback
Suggested rollback: No configuration removal is needed.

**One Unity Connection server + One Unified CM cluster + SCCP voice mail ports**

### Do
- In Unified CM Administration, navigate to Advanced Features > Voice Mail > Message Waiting[^39].
- Create two unique directory numbers in the voice mail pilot partition: one with Message Waiting Indicator set to On and one set to Off[^39][^66].
- Ensure these numbers are placed in a calling search space reachable by both the user phones and the voicemail ports[^38][^67].
- Verify that the dial plan does not contain patterns that overlap these MWI extensions[^68]. In SCCP, Unity Connection sends MWIs by placing calls to these numbers[^69].

### Verify
Suggested check: Confirm both MWI On and Off numbers exist in the pilot partition and are reachable by the ports' CSS.

### Rollback
Suggested rollback: Delete the MWI On and MWI Off directory numbers.

**One Unity Connection server + Two or more Unified CM clusters + SCCP voice mail ports**

### Do
- On each Unified CM cluster, navigate to Advanced Features > Voice Mail > Message Waiting[^39].
- Create unique MWI On and MWI Off directory numbers in the pilot partition with indicator states set to On and Off respectively[^39][^66].
- Confirm that the extensions reside in a calling search space accessible to user phones and voicemail ports[^38][^67].
- Confirm dial plans do not contain overlapping patterns for these MWI extensions[^68]. Unity Connection triggers MWIs by calling these numbers[^69].

### Verify
Suggested check: Verify that unique MWI On and Off numbers exist on each cluster without overlap.

### Rollback
Suggested rollback: Delete the MWI directory numbers from each cluster.

**Unity Connection cluster (active/active pair) + One Unified CM cluster + SCCP voice mail ports**

### Do
- In Unified CM Administration, go to Advanced Features > Voice Mail > Message Waiting[^39].
- Create two unique directory numbers in the pilot partition: one configured for Message Waiting Indicator On and one for Off[^39][^66].
- Assign them to a calling search space that contains the phones and the voicemail ports[^38][^67].
- Ensure no overlapping dial plan patterns exist for these MWI numbers[^68]. Unity Connection signals MWIs by calling these numbers[^69].

### Verify
Suggested check: Check that MWI On and Off numbers are active and reachable in the designated CSS.

### Rollback
Suggested rollback: Delete the MWI On and Off directory numbers.

**Unity Connection cluster (active/active pair) + Two or more Unified CM clusters + SCCP voice mail ports**

### Do
- On each Unified CM cluster, navigate to Advanced Features > Voice Mail > Message Waiting[^39].
- Create two unique directory numbers in the pilot partition, setting the indicator to On and Off respectively[^39][^66].
- Place them in a calling search space shared with the phones and voicemail ports[^38][^67].
- Confirm no dial plan overlap exists on any cluster[^68]. The voicemail system drives MWIs by calling these numbers[^69].

### Verify
Suggested check: Verify that MWI On and Off numbers are defined on each cluster without dial plan conflict.

### Rollback
Suggested rollback: Delete the MWI numbers from all clusters.

## Step 5: Configure the voice mail pilot and profile

**SIP trunk**

### Do
- In Unified CM Administration, go to Advanced Features > Voice Mail > Voice Mail Pilot to create a voice mail pilot matching the route pattern number, assign it a CSS that contains the user phones and the pilot partition, and check Make This the Default Voice Mail Pilot[^60].
- Go to Advanced Features > Voice Mail > Voice Mail Profile, create a profile pointing to this pilot, leave Voice Mail Box Mask blank unless multitenant services are used, and set it as the system default[^61].
- If multiple-tenant MWI notification is used, set the clusterwide service parameter Multiple Tenant MWI Modes to True; note that changing this parameter requires restarting Unified CM[^24][^70].

### Verify
Suggested check: Verify that the voice mail pilot and voice mail profile both display as the system default in Unified CM Administration.

### Rollback
- Suggested rollback: Assign default status to an alternate profile and pilot, then delete the newly created pilot and profile.
- If the Multiple Tenant MWI Modes parameter was modified, revert it and restart Unified CM[^24].

**SCCP voice mail ports**

### Do
- In Unified CM Administration, go to Advanced Features > Voice Mail > Voice Mail Pilot to create a voice mail pilot matching the SCCP hunt pilot number and check Make This the Default Voice Mail Pilot[^59].
- Go to Advanced Features > Voice Mail > Voice Mail Profile, create a profile referencing this pilot, leave Voice Mail Box Mask blank unless multitenant services are enabled, and check Make This the Default Voice Mail Profile[^61].
- Set the clusterwide service parameter Multiple Tenant MWI Modes to True only if multiple-tenant MWI notification is required; changing this parameter requires a Unified CM restart[^24][^70].

### Verify
Suggested check: Confirm that the pilot and profile are configured as system defaults.

### Rollback
- Suggested rollback: Select an alternate default profile and pilot, and delete the new entries.
- If the Multiple Tenant MWI Modes parameter was modified, revert it and restart Unified CM[^24].

## Step 6: Configure user call forwarding to voicemail

### Do
- Under Call Forward and Call Pickup Settings on the user directory number, check the Voice Mail box for desired call-forward triggers, such as Forward Busy Internal/External and Forward No Answer Internal/External[^16][^71][^72]. Unified CM uses the Voice Mail Profile configuration and ignores the Destination and Calling Search Space fields[^16].
- Note that checking the Voice Mail box for an internal forward type automatically checks it for the corresponding external forward type; manually uncheck the external box if external calls require different routing[^15].

### Verify
Suggested check: Verify on the user directory number configuration page that the Voice Mail boxes are selected for the intended forwarding types.

### Rollback
Suggested rollback: Uncheck the Voice Mail boxes on the directory number and save the line configuration.

## Step 7: Create the phone system and port group in Unity Connection

**SIP trunk**

### Do
- In Unity Connection Administration, navigate to Telephony Integrations > Phone System, select Add Port Group from Related Links, and choose the SIP port group template[^8].
- Enter the primary Unified CM server IP address and port[^8].
- Navigate to the Port Group Basics page, choose Edit > Servers, add secondary Unified CM servers ordered with the lowest number as primary, and reset the port group[^13].
- Ensure MWIs are enabled on the port group[^73].

### Verify
Suggested check: Verify that the port group shows all Unified CM servers in their designated order and displays a status of enabled.

### Rollback
Suggested rollback: Delete the SIP port group from the phone system.

**SCCP voice mail ports**

### Do
- In Unity Connection Administration, go to Telephony Integrations > Phone System, select Add Port Group from Related Links, and choose the SCCP port group template[^8].
- Enter the Device Name Prefix matching the voice mail server name configured in Unified CM[^42][^12]. Ensure this prefix is unique across all port groups to prevent multiple ports connecting to the same SCCP device[^11].
- Enter the MWI On Extension and MWI Off Extension matching the Message Waiting numbers configured in Unified CM[^12][^40][^74].
- Enter the primary Unified CM server address[^12]. Under Edit > Servers, add secondary Unified CM servers ordered with the lowest number as primary, and reset the port group[^13].
- Confirm that MWIs are enabled on the port group[^73]. During failover with active calls, ports may experience a registration delay when contacting the secondary server[^17].

### Verify
Suggested check: Check that the Device Name Prefix and MWI extensions match Unified CM settings exactly.

### Rollback
Suggested rollback: Delete the SCCP port group.

## Step 8: Add voice messaging ports and define port tasks

**One Unity Connection server**

### Do
- For each voice messaging port added to the port group, configure the check boxes for Enabled, Answer Calls, Perform Message Notification, Send MWI Requests, and Allow TRAP Connections[^7].
- Dedicate some ports to answering incoming calls and other ports to dialing out[^31]. Assign Send MWI Requests to designated ports to enable turning MWIs on and off[^75][^76]. Ensure ports not set to answer calls do not receive incoming calls[^32].

### Verify
Suggested check: Confirm that enabled ports are separated into answering and dial-out roles, and at least one port has Send MWI Requests enabled.

### Rollback
Suggested rollback: Delete or disable the ports in the port group.

**Unity Connection cluster (active/active pair)**

### Do
- In Unity Connection Administration, add ports to the port group, entering the total number of ports across both servers in the cluster under Number of Ports[^10].
- Assign each port to a specific server, allocating an equal number of answering ports and dial-out ports to both Unity Connection servers[^9].
- On individual ports, configure Enabled, Answer Calls, Perform Message Notification, Send MWI Requests, and Allow TRAP Connections[^7].
- Dedicate separate ports for answering and dial-out tasks[^31][^75][^76]. Ensure incoming calls never route to ports that do not answer[^32].

### Verify
Suggested check: Verify that sorting the port list by server shows an equal allocation of answering and dial-out ports on each cluster node.

### Rollback
Suggested rollback: Delete or disable the configured ports.

## Step 9: Add additional Unified CM clusters

**One Unified CM cluster**

### Do
- Skip this step, as each additional cluster is added as a separate phone system integration[^27].

### Verify
Suggested check: Confirm that only one phone system integration is configured.

### Rollback
Suggested rollback: No configuration removal is required.

**Two or more Unified CM clusters**

### Do
- For each additional Unified CM cluster, add a separate phone system integration by creating a new phone system, a new port group for it, and new ports for that port group[^27].
- When using SCCP, assign each port group a unique Device Name Prefix[^11].
- If Unity Connection must transfer callers between clusters, create a phone system trunk under Telephony Integrations > Trunk and specify the appropriate Trunk Access Code[^30].

### Verify
Suggested check: Confirm a distinct phone system entry exists for each connected cluster.

### Rollback
Suggested rollback: Delete the added phone system, associated trunks, port groups, and ports.

## Step 10: Configure AXL and import users

### Do
- In Unified CM, configure an application user with the Standard AXL API Access role[^1].
- In Unity Connection Administration, open Telephony Integrations > Phone System, select the phone system, and choose Edit > Cisco Unified Communications Manager AXL Servers[^2].
- Enter the server Order, IP Address, Port (matching port 80, 443 or 8443), Username, Password, and the corresponding Unified CM version[^2][^4]. Unity Connection uses AXL to import users and modify phone settings for personal call transfer rules[^3].
- Select the Test button to verify AXL connectivity[^4].
- Before importing, confirm that the user template's Phone System setting is set to this Unified CM phone system[^21].
- Navigate to Users > Import Users, select the phone system, select Find, select the target users, and choose Import Selected[^23]. Note that Unified CM users without a Primary Extension do not appear in this list[^22]. (Alternatively, users can be imported by integrating Unity Connection with an LDAP directory[^20].)

### Verify
Suggested check: Confirm that the AXL Test reports success and that imported accounts are visible under Users.

### Rollback
Suggested rollback: Delete the imported user accounts and remove the AXL server entry.

## Step 11: Verify telephony configuration and test call flows

### Do
- In Unity Connection Administration, run Check Telephony Configuration from the Related Links drop-down on any Telephony Integrations page[^5][^77]. If failures occur, review the Task Execution Results for diagnostic messages[^5]. This test verifies IPv4 communication with the phone system[^78].
- Under Telephony Integrations > Phone System, confirm that Force All MWIs Off for This Phone System is not enabled[^79][^80].
- Set up two test phones on the same phone system, configuring Phone 1 to forward unanswered calls to the voicemail pilot after no fewer than 4 rings, and ensure the test user on Phone 1's extension has MWI enabled[^57][^81][^82].
- Open Port Monitor from the Unity Connection interface and click Start Polling[^56].
- In the release-transfer test, leaving a message for the unanswered Phone 1 should turn its MWI on[^55][^83], and deleting the message after retrieving it should turn the MWI off[^55][^84].
- In the supervised-transfer test with 3 rings to wait, the caller hears no ringback while the port remains busy, and the greeting plays after 3 unanswered rings[^58]. On SIP trunk integrations, Unified CM Music on Hold is not played during supervised transfers[^48].
- If message-waiting indicators become misaligned, resynchronize them by selecting Run next to Synchronize All MWIs on This Phone System on the Phone System Basics page during periods of light traffic[^29][^85][^86][^87][^88][^89].

### Verify
Suggested check: Verify that personal greetings play, message-waiting indicators toggle correctly on message receipt and deletion, and Port Monitor displays active call state transitions.

### Rollback
Suggested rollback: Remove test call-forwarding rules from the test phone and delete any test user mailboxes created for verification.

## Applicability

Applies to: Cisco Unity Connection and Cisco Unified Communications Manager. Deployments: on-premises. Sources checked 2026-09-25. For multi-cluster deployments, Business Edition co-resident deployments on the same server as Unified CM are not supported[^25].

## What remains uncertain

- Sources disagree on whether there is a fixed maximum number of simultaneous phone system integrations: the multiple integration guide documents a limit of 28 total integrations (including 7 SCCP and 7 SIP Unified CM integrations)[^26], whereas the design guide states Unity Connection supports as many phone systems as needed up to the server or cluster port limit[^14].
- Configuration of authenticated or encrypted secure ports (such as TLS/SRTP or secure SCCP) and certificate handling is not covered by the sources below.
- LDAP directory schema mapping and synchronization mechanisms are not covered by the sources below.

## Sources

[^1]: The AXL server account configured in Unity Connection must be a Unified CM application user with the Standard AXL API Access role. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: Cisco Unified CM AXL Servers, Username. Checked 2026-09-25.
[^2]: AXL servers are configured from the phone system's Phone System Basics page, Edit > Cisco Unified Communications Manager AXL Servers, with Order, IP Address, Port, Username, Password and the Unified CM version (non-SSL or SSL matching port 80, 443 or 8443). Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: Cisco Unified CM AXL Servers. Checked 2026-09-25.
[^3]: Unity Connection uses the AXL server for importing Unified CM users and for changing certain phone settings used by personal call transfer rules. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: Cisco Unified CM AXL Servers. Checked 2026-09-25.
[^4]: Cisco's AXL tech note configures the AXL server on port 8443 and uses the Test button on the AXL servers page to verify connectivity. Source: [Integrate Users from CUCM to Unity Connection with AXL](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/220406-integrate-users-from-cucm-to-unity-conne.html), Configure, Unity Connection AXL server configuration. Checked 2026-09-25.
[^5]: Check Telephony Configuration is run from the Related Links list on Telephony Integrations pages, and if it fails the Task Execution Results show messages with troubleshooting steps. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting the Phone System Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01101.html), Troubleshooting the Phone System Integration, Check Telephony Configuration test. Checked 2026-09-25.
[^6]: The Cisco Unity Connection Compatibility Matrix lists Cisco Unified CM 15, 14 and 12.5(1) as supported with Unity Connection 15. Source: [Compatibility Matrix for Cisco Unity Connection](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/compatibility/matrix/b_cucclientmtx.html), Table 'Supported Version Combinations of Cisco Unity Connection 15, Cisco Unified CM, Cisco Unified CM Session Manager Edition and Cisco Unified CM Express', Unity Connection 15 row. Checked 2026-09-25.
[^7]: Each Unity Connection voice messaging port has settings for Enabled, Answer Calls, Perform Message Notification, Send MWI Requests and Allow TRAP Connections. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: configure Unity Connection, per-port settings. Checked 2026-09-25.
[^8]: In Unity Connection Administration, the port group is added from Telephony Integrations > Phone System via the Add Port Group related link, created from the SIP or SCCP port group template. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: configure Unity Connection, add port group. Checked 2026-09-25.
[^9]: In a Unity Connection cluster, each port is assigned to a specific server, and Cisco says to assign an equal number of answering and dial-out ports to the Unity Connection servers. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: configure Unity Connection, per-port settings. Checked 2026-09-25.
[^10]: When adding ports in Unity Connection, Number of Ports is the total for all Unity Connection servers in the cluster. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: configure Unity Connection, add ports. Checked 2026-09-25.
[^11]: The Device Name Prefix must be unique for each port group, otherwise more than one port may attempt to connect to the same SCCP device. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting the Phone System Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01101.html), Troubleshooting the Phone System Integration, SCCP port registration. Checked 2026-09-25.
[^12]: The Unity Connection SCCP port group requires a Device Name Prefix matching Unified CM and MWI On and MWI Off extensions, plus the primary Unified CM server address. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: configure Unity Connection, port group. Checked 2026-09-25.
[^13]: Secondary Unified CM servers are added to the port group from the Port Group Basics Edit > Servers page, ordered with the lowest number as primary, and the port group is reset afterwards. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: configure Unity Connection, servers. Checked 2026-09-25.
[^14]: The Unity Connection 15 design guide states that Unity Connection supports as many phone systems as needed, up to the maximum number of ports supported per server or active/active pair (disputed). Source: [Design Guide for Cisco Unity Connection 15 - Integrating Cisco Unity Connection with Phone System](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/design/guide/b_15cucdg/b_15cucdg_chapter_01010.html), Integrating with Multiple Phone Systems. Checked 2026-09-25.
[^15]: Checking the Voice Mail box for an internal forward type on a directory number automatically checks it for the matching external forward type; it must be unchecked manually to handle external calls differently. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Call Forwarding](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_c9779fc8_00_call-forwarding-12-0.html), Call Forwarding, Call Forward and Call Pickup Settings, Forward Busy/No Answer Internal. Checked 2026-09-25.
[^16]: When the Voice Mail check box is checked for a call-forward type on a Unified CM directory number, the value from the Voice Mail Profile is used and the Destination and Calling Search Space fields are ignored. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Call Forwarding](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_c9779fc8_00_call-forwarding-12-0.html), Call Forwarding, Directory Number Configuration, Call Forward and Call Pickup Settings, Voice Mail check box. Checked 2026-09-25.
[^17]: When Unified CM failover occurs while calls are in progress, the voice messaging ports may experience a delay registering with the secondary Unified CM server. Source: [Design Guide for Cisco Unity Connection 15 - Integrating Cisco Unity Connection with Phone System](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/design/guide/b_15cucdg/b_15cucdg_chapter_01010.html), Port Group Configuration for Cisco Unified Communications Manager Cluster Failover. Checked 2026-09-25.
[^18]: The design guide describes an optional failover configuration with two port groups, each holding half the ports (answering and dial-out), with the Unified CM servers listed in opposite order in each. Source: [Design Guide for Cisco Unity Connection 15 - Integrating Cisco Unity Connection with Phone System](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/design/guide/b_15cucdg/b_15cucdg_chapter_01010.html), Port Group Configuration for Cisco Unified Communications Manager Cluster Failover. Checked 2026-09-25.
[^19]: The Unified CM integration provides call forward to personal greeting, call forward to busy greeting, caller ID, easy message access, identified user messaging and message waiting indication. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Integration Description](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_00.html), Integration Description, integration functionality. Checked 2026-09-25.
[^20]: An alternative to importing users from Unified CM is to integrate Unity Connection with an LDAP directory and import user data from it. Source: [System Administration Guide for Cisco Unity Connection Release 15 - Users](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/administration/guide/b_15cucsag/b_12xcucsag_chapter_011.html), Users, Importing Users through AXL. Checked 2026-09-25.
[^21]: Before importing users through AXL, an AXL server must be configured for the source Unified CM, and the user template's Phone System field must be set to that Unified CM phone system. Source: [System Administration Guide for Cisco Unity Connection Release 15 - Users](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/administration/guide/b_15cucsag/b_12xcucsag_chapter_011.html), Users, Importing Users through AXL. Checked 2026-09-25.
[^22]: Unified CM users without a Primary Extension do not appear on the Unity Connection Users > Import Users page. Source: [System Administration Guide for Cisco Unity Connection Release 15 - Users](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/administration/guide/b_15cucsag/b_12xcucsag_chapter_011.html), Users, Importing Users through AXL. Checked 2026-09-25.
[^23]: Users are imported from Users > Import Users by selecting the Unified CM phone system, running Find, selecting the users and choosing Import Selected, then checking them under Users. Source: [Integrate Users from CUCM to Unity Connection with AXL](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/220406-integrate-users-from-cucm-to-unity-conne.html), Configure, import users. Checked 2026-09-25.
[^24]: The clusterwide service parameter Multiple Tenant MWI Modes is set to True only when multiple-tenant MWI notification is used, and changing it requires restarting Cisco Unified CM. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: voice mail server service parameters. Checked 2026-09-25.
[^25]: Multiple phone system integrations are not supported when Unity Connection is installed as Cisco Business Edition on the same server as Cisco Unified CM. Source: [Multiple Phone System Integration Guide for Cisco Unity Connection Release 15](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/multiple/b_cuc15intmultiple.html), Requirements for multiple integrations. Checked 2026-09-25.
[^26]: The Unity Connection 15 multiple integration guide lists a total of 28 simultaneous phone system integrations, including seven Cisco Unified CM integrations through SCCP and seven through SIP trunk (disputed). Source: [Multiple Phone System Integration Guide for Cisco Unity Connection Release 15](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/multiple/b_cuc15intmultiple.html), Supported combinations of phone system integrations. Checked 2026-09-25.
[^27]: Each additional Cisco Unified CM cluster is added to Unity Connection as a separate phone system integration by creating a new phone system, a new port group for it, and new ports for that port group. Source: [Multiple Phone System Integration Guide for Cisco Unity Connection Release 15](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/multiple/b_cuc15intmultiple.html), Multiple Cisco Unified CM clusters statement. Checked 2026-09-25.
[^28]: When Unity Connection integrates with multiple phone systems, all extensions must be unique and the dial plans of the phone systems must not overlap. Source: [Multiple Phone System Integration Guide for Cisco Unity Connection Release 15](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/multiple/b_cuc15intmultiple.html), Requirements for multiple integrations. Checked 2026-09-25.
[^29]: 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. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), Troubleshooting MWIs, synchronizing MWIs. Checked 2026-09-25.
[^30]: With multiple phone system integrations, a phone system trunk (Telephony Integrations > Trunk) with a Trunk Access Code lets Unity Connection transfer calls to extensions on another phone system. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: create phone system trunks. Checked 2026-09-25.
[^31]: For best performance, Cisco recommends dedicating some voice messaging ports to answering incoming calls and other ports to dialing out (MWI, notification, TRAP). Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Planning the Voice Messaging Ports in Cisco Unity Connection](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_15cucintcucmsip_chapter_01.html), Planning the Voice Messaging Ports, answering and dial-out ports. Checked 2026-09-25.
[^32]: Calls must not be sent to Unity Connection voice messaging ports that are not set to answer calls. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Planning the Voice Messaging Ports in Cisco Unity Connection](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_15cucintcucmsip_chapter_01.html), Planning the Voice Messaging Ports, caution on ports that cannot answer. Checked 2026-09-25.
[^33]: The total number of voice messaging ports across all Cisco Unified CM clusters integrated with Unity Connection cannot exceed the number of ports enabled by the Unity Connection licenses. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, Cisco Voice Mail Port Wizard, number of ports. Checked 2026-09-25.
[^34]: The SCCP hunt list has For Voice Mail Usage checked, contains the answering-port line group, and is reset after the line group is added. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: add hunt list. Checked 2026-09-25.
[^35]: The SCCP hunt pilot is placed in the voice mail pilot partition (example VMPilotNumberPT), points to the hunt list of answering ports, and must differ from the voice mail port extensions. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: add hunt pilot. Checked 2026-09-25.
[^36]: The SCCP line group distribution algorithm is Longest Idle Time for a single Unity Connection server and Top Down when a Unity Connection cluster is configured. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: add line group, Distribution Algorithm. Checked 2026-09-25.
[^37]: The SCCP line group contains only the voice mail ports that answer calls, not dial-out-only ports, with directory numbers in numerical sequence. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: add line group. Checked 2026-09-25.
[^38]: 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. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), Troubleshooting MWIs, Cisco Unified CM SCCP integration checks. Checked 2026-09-25.
[^39]: For an SCCP integration, two Message Waiting directory numbers are created under Advanced Features > Voice Mail > Message Waiting, one to turn MWI on and one to turn it off, both in the voice mail pilot partition. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: message waiting on and off numbers. Checked 2026-09-25.
[^40]: 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. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), Troubleshooting MWIs, Cisco Unified CM SCCP integration checks. Checked 2026-09-25.
[^41]: The SCCP procedure creates a partition for voice mail port directory numbers (example VMRestrictedPT), a partition for the hunt pilot (example VMPilotNumberPT) and a calling search space for the ports (example VMRestrictedCSS) that user phones do not use, so users cannot dial the ports directly. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, tasks: partitions and calling search space; voice mail port directory numbers. Checked 2026-09-25.
[^42]: SCCP voice mail ports are created with the Cisco Voice Mail Port Wizard (Advanced Features > Voice Mail > Cisco Voice Mail Port Wizard), and the voice mail server name must match the Device Name Prefix in Unity Connection. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: add voice mail ports with the Cisco Voice Mail Port Wizard. Checked 2026-09-25.
[^43]: In a Unity Connection integration with Cisco Unified CM, Unity Connection is installed on a separate server from Cisco Unified CM. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Integration Overview](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_00.html), Integration Overview, integration requirements. Checked 2026-09-25.
[^44]: The SIP trunk Destination Address is the Unity Connection server IP address, and Cisco recommends accepting the default destination port 5060. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create SIP trunk, Destination Address and Destination Port. Checked 2026-09-25.
[^45]: On the SIP trunk to Unity Connection, Redirecting Diversion Header Delivery is checked for both Inbound and Outbound. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create SIP trunk. Checked 2026-09-25.
[^46]: With a Unity Connection cluster on SIP, the voice mail pilot route pattern should target the route list rather than a single trunk, so calls reach the second server when the first is unavailable (inferred). Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, tasks: create route pattern; create route group; create route list. Checked 2026-09-25.
[^47]: A SIP trunk integration needs no MWI on/off directory numbers in Unified CM; MWI requests arrive over the trunk as unsolicited notifications that the trunk security profile must accept (inferred). Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, SIP trunk security profile task (Accept Unsolicited Notification) and absence of a Message Waiting task. Checked 2026-09-25.
[^48]: Cisco Unified CM Music on Hold is not available during supervised transfers for the Cisco Unified CM SIP trunk integration. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, note on Music on Hold. Checked 2026-09-25.
[^49]: The SIP trunk integration uses a SIP profile created by copying an existing profile under Device > Device Settings > SIP Profile, with Enable ANAT checked only for IPv6 or dual-stack. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create SIP profile. Checked 2026-09-25.
[^50]: On the SIP trunk, the inbound Calling Search Space, Rerouting Calling Search Space and Out-of-Dialog Refer Calling Search Space are each set to a calling search space that contains the user phones. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create SIP trunk. Checked 2026-09-25.
[^51]: When Unity Connection is a cluster, the SIP trunks to its servers are placed in a route group with the Top Down distribution algorithm, with the subscriber server's trunk listed first. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create route group (cluster only). Checked 2026-09-25.
[^52]: When Unity Connection is a cluster, a route list containing the SIP trunk route group is created, and the route list is reset after it is saved. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create route list (cluster only). Checked 2026-09-25.
[^53]: For the SIP trunk integration, a route pattern equal to the voice mail pilot number is created under Call Routing > Route/Hunt > Route Pattern and pointed at the Unity Connection SIP trunk. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create route pattern. Checked 2026-09-25.
[^54]: For a SIP trunk integration, create a SIP trunk security profile under System > Security > SIP Trunk Security Profile with Accept Out-of-Dialog REFER, Accept Unsolicited Notification and Accept Replaces Header checked. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create SIP trunk security profile. Checked 2026-09-25.
[^55]: In the release-transfer test, leaving a message for the unanswered Phone 1 should turn its MWI on, and deleting the message after retrieving it should turn the MWI off. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Testing the Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_15cucintcucmsip_chapter_011.html), Testing the Integration, release transfer and listening to messages. Checked 2026-09-25.
[^56]: During testing, port activity is watched with Port Monitor, opened from the Unity Connection menu, by selecting Start Polling. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Testing the Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_15cucintcucmsip_chapter_011.html), Testing the Integration, Port Monitor. Checked 2026-09-25.
[^57]: Cisco's integration test uses two test phones on the same phone system, with Phone 1 forwarding unanswered calls to the Unity Connection pilot after no fewer than four rings, and a test user on Phone 1's extension with MWIs enabled. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Testing the Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_15cucintcucmsip_chapter_011.html), Testing the Integration, setting up the test configuration. Checked 2026-09-25.
[^58]: In the supervised-transfer test with three rings to wait, the caller hears no ringback (is on hold), the port stays Busy during supervision, and the greeting plays after three unanswered rings. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Testing the Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_15cucintcucmsip_chapter_011.html), Testing the Integration, supervised transfer. Checked 2026-09-25.
[^59]: For the SCCP integration, the voice mail pilot extension matches the hunt pilot number and Make This the Default Voice Mail Pilot is checked. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, task: voice mail pilot. Checked 2026-09-25.
[^60]: For the SIP trunk integration, the voice mail pilot number (Advanced Features > Voice Mail > Voice Mail Pilot) must match the route pattern, uses a calling search space containing the user phones and the pilot partition, and is made the system default. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: create voice mail pilot. Checked 2026-09-25.
[^61]: A voice mail profile (Advanced Features > Voice Mail > Voice Mail Profile) selects the voice mail pilot, leaves Voice Mail Box Mask blank unless multitenant services are enabled, and is made the system default. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, task: set up voice mail profile. Checked 2026-09-25.
[^62]: The same Unity Connection SIP trunk security profile must also have Accept Out-of-Dialog REFER and Accept Replaces Header checked. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, SIP trunk security profile task step 3, Table 2. Checked 2026-09-25.
[^63]: For a Unified CM SIP trunk integration with Unity Connection, the SIP trunk security profile used by the Unity Connection trunk must have Accept Unsolicited Notification checked. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, SIP trunk security profile task step 3, Table 2. Checked 2026-09-25.
[^64]: Unified CM documents that a SIP integration with Unity Connection uses a single trunk per Unity Connection server and removes the need to configure directory numbers for voicemail ports and MWI. Source: [System Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Integrate Cisco Applications](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_011000.html), Integrate Cisco Applications > Cisco Unity Connection. Checked 2026-09-25.
[^65]: In Unified CM, the Accept Unsolicited Notification field of a SIP trunk security profile makes Unified CM accept incoming non-INVITE unsolicited notification messages that arrive over the SIP trunk. Source: [Security Guide for Cisco Unified Communications Manager, Release 15 and SUs - Trunk and Gateway SIP Security](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/security/15_0/cucm_b_security-guide-release-15/cucm_m_trunk-and-gateway-sip-security_reog.html), SIP Trunk Security Profile Settings, field 'Accept Unsolicited Notification'. Checked 2026-09-25.
[^66]: The SCCP integration guide has the MWI On and MWI Off numbers configured as two unique extensions in the same partition (the voice mail pilot partition in its example), with Message Waiting Indicator set to On and Off respectively and the calling search space used by user phones. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Specifying the MWI Directory Numbers, steps 2 to 7. Checked 2026-09-25.
[^67]: 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. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), MWIs Do Not Turn On or Off, SCCP-only calling search space task (task 11 in the Release 14 ordering). Checked 2026-09-25.
[^68]: For Cisco Unified CM SCCP integrations only, the dial plan must not contain patterns that overlap the MWI extensions. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), MWIs Do Not Turn On or Off, SCCP-only dial plan task (task 12 in the Release 14 ordering). Checked 2026-09-25.
[^69]: In an SCCP integration, the voicemail system sends MWIs by calling a message-waiting on number or off number in Unified CM. Source: [System Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Integrate Cisco Applications](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_011000.html), Integrate Cisco Applications > Cisco Unity Connection (SCCP protocol). Checked 2026-09-25.
[^70]: Setting the Unified CM clusterwide service parameter Multiple Tenant MWI Modes (Cisco CallManager service, Feature - General) to True makes Unified CM apply configured translation patterns to convert voicemail extensions into directory numbers when turning MWIs on or off. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, voice mail server service parameters steps 4 to 5. Checked 2026-09-25.
[^71]: In Unified CM, Call Forward Busy (internal and external) forwards calls only when the line is in use and the configured Call Forward Busy trigger value is reached. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Call Forwarding](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_c9779fc8_00_call-forwarding-12-0.html), Call Forwarding Overview; Call Forward Busy Internal/External definition. Checked 2026-09-25.
[^72]: In Unified CM, Call Forward No Answer forwards a call when the phone is not answered before the No Answer Ring Duration expires or when the destination is unregistered. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Call Forwarding](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_c9779fc8_00_call-forwarding-12-0.html), Call Forwarding Overview; Call Forward No Answer Internal/External definition. Checked 2026-09-25.
[^73]: Cisco's MWI checklist requires confirming that the port groups in the integration have MWIs enabled. Source: [Troubleshooting Guide for Cisco Unity Connection Release 14 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/14/troubleshooting/guide/b_14cuctsg/b_14cuctsg_chapter_01110.html), MWI Problems > MWIs Do Not Turn On or Off, task 5. Checked 2026-09-25.
[^74]: In an SCCP integration, the Unity Connection port group's MWI On Extension and MWI Off Extension must match the MWI On and Off numbers configured in Unified CM. Source: [Cisco Unified Communications Manager SCCP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SCCP Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sccp/b_15cucintcucmskinny/b_14cucintcucmskinny_chapter_010.html), Setting Up a Cisco Unified CM SCCP Integration, port group settings. Checked 2026-09-25.
[^75]: On a Unity Connection voice messaging port, the Send MWI Requests check box designates that port for turning MWIs on and off. Source: [Cisco Unified Communications Manager SIP Integration Guide for Cisco Unity Connection Release 15 - Setting Up a Cisco Unified Communications Manager SIP Trunk Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/integration/cucm_sip/b_15cucintcucmsip/b_14cucintcucmsip_chapter_010.html), Setting Up a Cisco Unified CM SIP Trunk Integration, port settings table. Checked 2026-09-25.
[^76]: Cisco's MWI checklist requires confirming that voice messaging ports in the phone system integration are assigned to send MWI requests, that those ports are enabled, and that enough ports are so assigned. Source: [Troubleshooting Guide for Cisco Unity Connection Release 14 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/14/troubleshooting/guide/b_14cuctsg/b_14cuctsg_chapter_01110.html), MWI Problems > MWIs Do Not Turn On or Off, tasks 2 to 4. Checked 2026-09-25.
[^77]: The first task in Cisco's 'MWIs Do Not Turn On or Off' procedure is to run the Check Telephony Configuration test, reachable from Related Links on Telephony Integrations pages. Source: [Troubleshooting Guide for Cisco Unity Connection Release 14 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/14/troubleshooting/guide/b_14cuctsg/b_14cuctsg_chapter_01110.html), MWI Problems > MWIs Do Not Turn On or Off, task 1. Checked 2026-09-25.
[^78]: The Unity Connection Check Telephony Configuration test does not test IPv6 connectivity; it confirms IPv4 communication with the phone system only. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), MWIs Do Not Turn On or Off, Check Telephony Configuration task note. Checked 2026-09-25.
[^79]: Checking 'Force All MWIs Off for This Phone System' and saving turns off all MWIs for that phone system integration. Source: [Troubleshooting Guide for Cisco Unity Connection Release 14 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/14/troubleshooting/guide/b_14cuctsg/b_14cuctsg_chapter_01110.html), MWIs Do Not Turn On or Off, task on MWIs forced off at phone system level. Checked 2026-09-25.
[^80]: Cisco's MWI checklist requires confirming that MWIs are not forced off at the phone system level. Source: [Troubleshooting Guide for Cisco Unity Connection Release 14 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/14/troubleshooting/guide/b_14cuctsg/b_14cuctsg_chapter_01110.html), MWI Problems > MWIs Do Not Turn On or Off, task 8. Checked 2026-09-25.
[^81]: Whether MWI is enabled for a user is checked with the Enabled check box at Users > Users > Message Waiting Indicators in Cisco Unity Connection Administration. Source: [Troubleshooting Guide for Cisco Unity Connection Release 14 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/14/troubleshooting/guide/b_14cuctsg/b_14cuctsg_chapter_01110.html), MWI Problems > MWIs Do Not Turn On or Off, task 9. Checked 2026-09-25.
[^82]: Cisco's MWI checklist requires confirming that the correct phone system is assigned to the user's MWI. Source: [Troubleshooting Guide for Cisco Unity Connection Release 14 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/14/troubleshooting/guide/b_14cuctsg/b_14cuctsg_chapter_01110.html), MWI Problems > MWIs Do Not Turn On or Off, task 10. Checked 2026-09-25.
[^83]: 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. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), Triggers for Turning MWIs On and Off. Checked 2026-09-25.
[^84]: 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. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), Triggers for Turning MWIs On and Off. Checked 2026-09-25.
[^85]: Running MWI synchronization for a phone system integration can delay MWIs for new messages because of the additional MWI requests being processed. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), MWI Problems > Delay for MWIs to Turn On or Off. Checked 2026-09-25.
[^86]: When MWIs are synchronized, Unity Connection queries its message store to determine the MWI status for all phones and resets the applicable MWIs. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), MWIs Do Not Turn On or Off, synchronization task. Checked 2026-09-25.
[^87]: In Unity Connection Administration, selecting Run next to 'Synchronize All MWIs on This Phone System' on the Phone System Basics page synchronizes MWIs for that phone system without affecting MWIs on other phone systems. Source: [System Administration Guide for Cisco Unity Connection Release 15 - Telephony Integration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/administration/guide/b_15cucsag/b_15cucsag_chapter_0110.html), Phone System > Phone System Basics. Checked 2026-09-25.
[^88]: Cisco warns that synchronizing MWIs for a phone system may affect system performance and recommends doing it when phone traffic is light. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), MWIs Do Not Turn On or Off, synchronization procedure note. Checked 2026-09-25.
[^89]: MWI synchronization is itself one of the documented triggers for Unity Connection to turn MWIs on or off. Source: [Troubleshooting Guide for Cisco Unity Connection Release 15 - Troubleshooting Message Waiting Indicators (MWIs)](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/15/troubleshooting/guide/b_15cuctsg/b_15cuctsg_chapter_01110.html), Triggers for Turning MWIs On and Off. Checked 2026-09-25.