# Setting up Extension Mobility in Unified CM

Systems: cucm

For Unified CM administrators setting up Extension Mobility on a Release 15 cluster.

Canonical: https://warmtransfer.net/guides/cucm-extension-mobility-setup

Last verified: 2026-09-30

Cisco Extension Mobility allows users to access their phone settings temporarily, including line appearances, services, and speed dials, from other phones across the system[^41]. The configuration tasks follow a sequence through Cisco Unified CM Administration, Cisco Unified Serviceability, and Cisco Unified Reporting[^53].

## Before you start

Before starting, verify that a TFTP server is reachable[^44]. Extension Mobility requires a physical Cisco Unified IP Phone, so remote logins cannot be used[^43]. Cisco provides Extension Mobility setup instructions for Cisco Desk Phone 9800 Series phones on [Unified CM](https://warmtransfer.net/knowledge/cisco-unified-cm), which follow the same stages as the feature guide[^1]. If you plan to deploy Extension Mobility Cross Cluster (EMCC), ensure that a second call-control entity configured for EMCC is available, clusters run in nonsecure or mixed mode, and phones operate in secure or nonsecure mode[^16]. In addition, the remote EMCC cluster must support the minimum TLS version configured on the home cluster[^22]. Note that EMCC does not support intercom, location-based call admission control, or IPv6-only phones[^18].

## What changes by situation

- Will users log in only on the phone model their device profile was built for, or on other models too? Users only log in on the model their profile was built for; Users may log in on models they have no profile for.
- What should users type to log in? User ID and PIN; Primary extension and PIN; Self Service User ID and PIN.
- May one user be logged in on several phones at once? No. A second login is refused; Yes. A user can be logged in on several phones; No, but a second login should move the user: the first phone is logged out.
- Should logins expire on their own? No. Users stay logged in until they log out; Yes. Log users out after a maximum time.
- Do users only log in on phones in their own cluster, or also on phones in another cluster? Own cluster only; Also phones in another cluster (EMCC).

## Step 1: Confirm phone model support

### Do
Open Cisco Unified Reporting, select System Reports, and click Unified CM Phone Feature List[^27]. Generate a new report or open the existing report, set Product to All, select the extension mobility feature, and click Submit[^27]. Exclude any protected phones configured with secure tone, because Extension Mobility is disabled on protected phones[^46].

### Verify
Verify that every phone model intended for Extension Mobility appears in the generated feature list report[^27].

### Rollback
Suggested rollback: Close the report window without making system adjustments.

## Step 2: Activate Extension Mobility services

### Do
In Cisco Unified Serviceability, navigate to Tools > Service Activation and choose the target node[^51]. Activate Cisco CallManager, Cisco Tftp, Cisco Extension Mobility, and ILS Service, then save the configuration[^51]. Ensure that ILS Service is activated on the publisher node[^28].

### Verify
Under Tools > Control Center - Feature Services in Cisco Unified Serviceability, verify that the Cisco Extension Mobility service shows a running status[^26].

### Rollback
Suggested rollback: Return to Service Activation, uncheck the activated services if they are not needed by other workloads, and save.

## Step 3: Create the Extension Mobility phone service

**User ID and PIN**

### Do
In Cisco Unified CM Administration, navigate to Device > Device Settings > Phone Services and click Add New[^42]. Enter a Service Name, set Service Type to define whether the service appears under the Services, Directories, or Messages button, and enter the case-sensitive Service URL `http://<IP Address>:8080/emapp/EMAppServlet?device=#DEVICENAME#` or append `&loginType=UID`[^42][^49][^50][^33][^34]. If using an IPv6 address, format it in square brackets[^50]. Save the phone service[^42].

### Verify
Suggested check: Check that the service appears in the Phone Services list with the configured Service URL.

### Rollback
Suggested rollback: Open the service in Phone Services and click Delete.

**Primary extension and PIN**

### Do
In Cisco Unified CM Administration, navigate to Device > Device Settings > Phone Services and click Add New[^42]. Enter a Service Name, set Service Type to define whether the service appears under the Services, Directories, or Messages button, and configure the case-sensitive Service URL by appending `&loginType=DN` to the base URL so users sign in with Primary Extension and PIN[^42][^49][^50][^34]. If using an IPv6 address, format it in square brackets[^50]. Save the phone service[^42].

### Verify
Suggested check: Check that the service appears in the Phone Services list with the configured Service URL.

### Rollback
Suggested rollback: Open the service in Phone Services and click Delete.

**Self Service User ID and PIN**

### Do
In Cisco Unified CM Administration, navigate to Device > Device Settings > Phone Services and click Add New[^42]. Enter a Service Name, set Service Type to define whether the service appears under the Services, Directories, or Messages button, and configure the case-sensitive Service URL by appending `&loginType=SP` to the base URL so users sign in with Self Service User ID and PIN[^42][^49][^50][^34]. If using an IPv6 address, format it in square brackets[^50]. Save the phone service[^42].

### Verify
Suggested check: Check that the service appears in the Phone Services list with the configured Service URL.

### Rollback
Suggested rollback: Open the service in Phone Services and click Delete.

## Step 4: Configure default device profiles

**Users only log in on the model their profile was built for**

### Do
Skip configuring default device profiles, because a user whose profile matches the physical phone model will have their user device profile applied directly upon login[^45].

### Verify
Suggested check: Confirm that each target user device profile matches the model of the physical phones deployed for login.

### Rollback
Suggested rollback: No configuration changes were made to revert.

**Users may log in on models they have no profile for**

### Do
In Cisco Unified CM Administration, navigate to Device > Device Settings > Default Device Profile[^10]. Select the target model in Device Profile Type, click Next, select the Device Protocol, click Next, configure the fields (such as user locale, phone button template, softkey template, and MLPP settings), and save[^10][^8]. Repeat this for every phone model where users may log in without a matching device profile[^10][^8].

### Verify
Suggested check: Confirm that a default device profile is listed under Default Device Profile for every relevant phone model.

### Rollback
Open each configured default device profile under Device > Device Settings > Default Device Profile and restore the previous settings or adjust the fields[^10].

## Step 5: Create user device profiles

### Do
Navigate to Device > Device Settings > Device Profile and click Add New[^11]. Select the Device Profile Type, click Next, choose the Device Protocol, click Next, configure the profile fields, and save[^11]. Under Association Information, click Add a new DN, enter the user's directory number, save, and click Reset[^11]. For multiple profiles, the [Bulk Administration Tool](https://warmtransfer.net/knowledge/cucm-bulk-administration-tool) can be used to add several user device profiles at one time[^4].

### Verify
Suggested check: Locate the user device profile in Device > Device Settings > Device Profile and confirm the assigned directory number is listed.

### Rollback
Suggested rollback: Locate the profile in Device > Device Settings > Device Profile and delete it.

## Step 6: Associate device profiles to end users

### Do
Navigate to User Management > End User and open the target user account[^2]. In the Extension Mobility section, move the profile from Available Profiles to Controlled Profiles, check the Home Cluster check box, and save[^2].

### Verify
Verify that the device profile is present under Controlled Profiles, ensuring the user avoids error 205 (User Profile Absent) during login[^2][^25].

### Rollback
Open the user under User Management > End User, move the profile from Controlled Profiles back to Available Profiles, and save[^2].

## Step 7: Subscribe phones and device profiles and enable login

### Do
Open each physical phone intended for Extension Mobility under Device > Phone[^52]. Check the Enable Extension Mobility check box in the Phone Configuration window and save[^23]. From Related Links, select Subscribe/Unsubscribe Services, click Go, select the Extension Mobility service, click Next, click Subscribe, and save and close the window[^52]. Repeat the subscription process for each user device profile under Device > Device Settings > Device Profile using Subscribe/Unsubscribe Services[^52].

### Verify
WarmTransfer's reading of the sources is that a phone accepts Extension Mobility logins only when both its Enable Extension Mobility check box is checked and it is subscribed to the service[^32]. Verify that the Extension Mobility service appears on the phone services menu; if it is missing after login, verify that the profile is subscribed, and if missing after logout, verify that the phone is subscribed[^57].

### Rollback
Open Device > Phone or Device > Device Settings > Device Profile, open Subscribe/Unsubscribe Services from Related Links, and remove the Extension Mobility subscription[^52]. On the physical phone, uncheck Enable Extension Mobility and save[^23].

## Step 8: Configure multiple login behavior

**No. A second login is refused**

### Do
Navigate to System > Service Parameters, select a node running the Cisco Extension Mobility service, and select the Cisco Extension Mobility service[^48]. Click Advanced to reveal all parameters, leave Multiple Login Behavior set to Multiple Logins Not Allowed (the default setting), and save[^48][^40].

### Verify
Verify that when a test user is logged in to a phone, an attempt to log in to a second phone fails and the phone displays error code 25[^39].

### Rollback
Suggested rollback: No service parameter adjustments were made from the default.

**Yes. A user can be logged in on several phones**

### Do
Navigate to System > Service Parameters, select a node running the Cisco Extension Mobility service, and select the Cisco Extension Mobility service[^48]. Click Advanced to reveal all parameters, set Multiple Login Behavior to Multiple Logins Allowed, and save[^48][^40].

### Verify
Verify that a user who is logged in to one phone can complete a second login on another device without triggering error code 25[^39].

### Rollback
In System > Service Parameters for Cisco Extension Mobility, change Multiple Login Behavior back to Multiple Logins Not Allowed and save[^40].

**No, but a second login should move the user: the first phone is logged out**

### Do
Navigate to System > Service Parameters, select a node running the Cisco Extension Mobility service, and select the Cisco Extension Mobility service[^48]. Click Advanced to reveal all parameters, set Multiple Login Behavior to Auto Logout, and save[^48][^40].

### Verify
Verify that when a user logs in to a second phone, Unified CM logs the user out of the first device automatically[^3].

### Rollback
In System > Service Parameters for Cisco Extension Mobility, set Multiple Login Behavior back to Multiple Logins Not Allowed and save[^40].

## Step 9: Configure login time limits

**No. Users stay logged in until they log out**

### Do
Navigate to System > Service Parameters, select the node and the Cisco Extension Mobility service, click Advanced, and ensure Enforce Intra-cluster Maximum Login Time remains set to False (the default)[^48][^38].

### Verify
Suggested check: Verify that Enforce Intra-cluster Maximum Login Time displays False in the service parameters.

### Rollback
Suggested rollback: No parameter changes were made from the default value.

**Yes. Log users out after a maximum time**

### Do
Navigate to System > Service Parameters, select the node and the Cisco Extension Mobility service, and click Advanced[^48]. Set Enforce Intra-cluster Maximum Login Time to True, enter Intra-cluster Maximum Login Time in HHH:MM format within the allowed range of 0:00 to 168:00, and save[^38].

### Verify
Verify that after the configured time interval expires, the logged-in user is automatically logged out, Unified CM sends the logout profile, and the phone restarts[^38][^36].

### Rollback
In System > Service Parameters for Cisco Extension Mobility, set Enforce Intra-cluster Maximum Login Time back to False and save[^38].

## Step 10: Configure the Change Credential service (Optional)

### Do
Under Device > Device Settings > Phone Services, create a phone service named Change Credential with Service URL `http://server:8080/changecredential/ChangeCredentialServlet?device=#DEVICENAME#` (or optionally a Secure-Service URL on port 8443 using https with the same path) and save[^6]. Subscribe the relevant phones to this service using Related Links > Subscribe/Unsubscribe Services[^6].

### Verify
Verify that the Change Credential service appears on the subscribed phone's services menu[^6]. Note that Extension Mobility caches logged-in user information for 2 minutes, so both old and new PINs can work immediately following a change[^5].

### Rollback
Open Device > Phone, access Subscribe/Unsubscribe Services, unsubscribe the phone from the Change Credential service, and save[^52].

## Step 11: Configure cluster scope

**Own cluster only**

### Do
Keep the existing single-cluster configuration, as Extension Mobility operates within one cluster without additional cross-cluster components[^14].

### Verify
Suggested check: Proceed directly to Step 12 for final login and logout testing.

### Rollback
Suggested rollback: No cross-cluster changes were configured to revert.

**Also phones in another cluster (EMCC)**

### Do
Configure the Extension Mobility phone service URL with the EMCC parameter: `http://<IP Address>:8080/emapp/EMAppServlet?device=#DEVICENAME#&EMCC=#EMCC#`[^19]. Ensure that Extension Mobility steps are completed on both the home and remote clusters[^21]. In the order defined by Cisco, configure certificates, configure devices and templates, configure a geolocation filter, configure EMCC feature parameters, configure an intercluster SIP trunk with Trunk Service Type set to Extension Mobility Cross Clusters, configure an intercluster service profile, and configure remote cluster services[^20][^21]. For certificate trust, activate the Bulk Provisioning Service, export certificates from each cluster to the same SFTP server and directory, consolidate them, and import the consolidated set back into each cluster[^13].

### Verify
Verify that after a cross-cluster login, the visiting phone downloads its configuration from the home cluster's TFTP server and registers to the home cluster[^17]. Note that the Multiple Login Behavior enforced during an EMCC login is the value configured on the home cluster, not the visiting cluster[^15].

### Rollback
Suggested rollback: Revert the phone service URL to remove the EMCC parameter, remove the intercluster SIP trunk and remote cluster service configurations, and delete imported cross-cluster certificates.

## Step 12: Test login and logout

### Do
On a subscribed phone, open the Extension Mobility phone service and enter the configured credentials[^34]. After validating the session, navigate to the phone services menu and initiate a logout[^36].

### Verify
Verify that upon login the phone takes on the user's line appearances, services, and speed dials[^41]. If the user locale differs from the phone locale, observe that the phone restarts and resets to rebuild its configuration file, which requires no administrative action[^31]. Verify that upon logout, Unified CM sends the logout profile to the phone and the phone restarts[^36]. If login fails:
- error 22 (Dev Logon Disabled): Ensure Enable Extension Mobility is checked on the phone[^23].
- Error code 25: Check whether the user is logged into another phone under Multiple Logins Not Allowed[^39].
- error 26 (Busy Please Try Again): Check whether concurrent login/logout requests exceed the configured Maximum Concurrent Requests value (default 5)[^37].
- Error 201 (Authentication Error): Verify the entered user ID and PIN[^24].
- Error 205 (User Profile Absent): Associate a device profile with the user account[^25].
- EM Service Connection Error: In Cisco Unified Serviceability, verify Cisco Extension Mobility is running under Tools > Control Center - Feature Services[^26].
- Host Not Found or HTTP 503: Verify Cisco Tomcat, Cisco IP Phone Services, and Cisco Extension Mobility Application are running under Tools > Control Center - Network Services[^26].
- If troubleshooting is still required, confirm the case-sensitive service URL and enable Cisco Extension Mobility tracing in Cisco Unified Serviceability under Trace > Trace Configuration[^49][^54].

### Rollback
Suggested rollback: Log the test user account out of the physical phone.

## Applicability

Applies to: Cisco Desk Phone 9800 Series and Cisco Unified Communications Manager. Deployments: on-premises. Sources checked 2026-09-30. Version 15 was released on 16 October 2023 and is the latest major release listed on Cisco support pages[^60]. EMCC multi-login behavior enforcement on the home cluster applies to CUCM 12.5 and later[^15].

## What remains uncertain

The exact procedure to configure the phone's Log Out Profile field, and what the phone displays while no user is logged in, is not covered by the sources below. Enterprise subscription methods for pushing Extension Mobility to all phones at once without per-device navigation are not covered by the sources below. Configuring the core Extension Mobility phone service over HTTPS is not covered by the sources below. Detailed step-by-step UI procedures for every EMCC screen beyond the high-level task order are not covered by the sources below. Whether IPv6-only phones can run Extension Mobility in all topologies is not covered by the sources below. Hardening Extension Mobility using Validate IP Address, the trusted IP list, and Allow Proxy is not covered by the sources below. The impact of setting Clear Call Logs on Intra-Cluster EM across different firmware models is not covered by the sources below.

## Sources

[^1]: Cisco publishes Extension Mobility setup instructions for Cisco Desk Phone 9800 Series phones registered to Unified CM, following the same stages as the Unified CM feature guide. Source: [Set up extension mobility on 9800 (Unified CM)](https://help.webex.com/article/n44dllf/Set-up-extension-mobility-on-9800-(Unified-CM)), Article body, overview and task list. Checked 2026-09-30.
[^2]: A device profile is associated to a user at User Management > End User: in the Extension Mobility section move the profile from Available Profiles to Controlled Profiles, check the Home Cluster check box, and save. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Associate a Device Profile to a User, steps 1-4. Checked 2026-09-30.
[^3]: With Multiple Login Behavior set to Auto Logout, logging in to a second device, by Extension Mobility or Extension Mobility Cross Cluster, makes Unified CM log the user out of the first device automatically. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Multiple Login Behavior, Auto Logout. Checked 2026-09-30.
[^4]: The Bulk Administration Tool can add and delete several user device profiles for Extension Mobility at one time. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Associate a Device Profile to a User, note. Checked 2026-09-30.
[^5]: Extension Mobility caches logged-in user information for 2 minutes and validates requests against the cache, so just after a PIN change both the old and the new PIN can work. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Restrictions table, Cache. Checked 2026-09-30.
[^6]: To let users change their PIN from the phone, create a phone service named Change Credential with Service URL http://server:8080/changecredential/ChangeCredentialServlet?device=#DEVICENAME# (optionally a Secure-Service URL on https port 8443 with the same path) and subscribe phones to it through Subscribe/Unsubscribe Services. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Configure the Change Credential IP Phone Service, steps 1-7. Checked 2026-09-30.
[^7]: Setting Clear Call Logs on Intra-Cluster EM to True clears the phone's call logs during manual Extension Mobility login and logout. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Clear Call Logs on Intra-Cluster EM. Checked 2026-09-30.
[^8]: A phone takes on the default device profile whenever a user logs in to a phone for which they have no user device profile; the default device profile holds device type, user locale, phone button template, softkey template and MLPP information. Source: [System Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Configure Endpoints](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_011101.html), Configure Default Device Profiles, introduction. Checked 2026-09-30.
[^9]: When the login profile does not match the phone being logged in to, the system loads the device profile default for that phone model, using it for the phone button and softkey templates while copying device-independent settings such as directory numbers, speed dials, locale and user hold audio from the user's profile. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Overview. Checked 2026-09-30.
[^10]: A default device profile is configured at Device > Device Settings > Default Device Profile: choose the phone model in Device Profile Type, click Next, choose the Device Protocol, click Next, configure the fields and save. Source: [System Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Configure Endpoints](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_011101.html), Configure Default Device Profiles, steps 1-6. Checked 2026-09-30.
[^11]: A user device profile is created at Device > Device Settings > Device Profile: Add New, choose the Device Profile Type and then the Device Protocol, configure and save, then under Association Information click Add a new DN, enter the directory number, save, and click Reset. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Create an Extension Mobility Device Profile for Users, steps 1-7. Checked 2026-09-30.
[^12]: An Extension Mobility device profile acts as a virtual device that maps onto a physical device when a user logs in. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Configuration Task Flow table, row 4. Checked 2026-09-30.
[^13]: EMCC trust between clusters is set up with bulk certificate management: activate the Bulk Provisioning Service, export certificates from each cluster to the same SFTP server and directory, consolidate them, and import the consolidated set back into each cluster. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Configure Certificates for Extension Mobility Cross Cluster. Checked 2026-09-30.
[^14]: Extension Mobility works on phones within one Unified CM cluster; Extension Mobility Cross Cluster (EMCC) lets a user from one cluster, the home cluster, log in to a phone on another, the visiting cluster. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Extension Mobility Cross Cluster Overview. Checked 2026-09-30.
[^15]: Since CUCM 12.5 the Multiple Login Behavior parameter also governs EMCC logins, and the value configured on the home cluster is the one enforced, not the visiting cluster's. Source: [Extension Mobility and Extension Mobility Cross Cluster: Changes in CUCM 12.5](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/214055-extension-mobility-and-extension-mobilit.html), Multiple Login Behavior service parameter description. Checked 2026-09-30.
[^16]: EMCC prerequisites are another call-control entity that supports and is configured for EMCC, such as a second Unified CM cluster, with clusters in nonsecure or mixed mode and supported phones in secure or nonsecure mode. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Extension Mobility Cross Cluster Prerequisites. Checked 2026-09-30.
[^17]: After a successful EMCC login the visiting phone downloads its configuration from the home cluster's TFTP server and registers to the home cluster. Source: [Troubleshoot Extension Mobility Cross Cluster (EMCC)](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/214535-troubleshoot-extension-mobility-cross-cl.html), EMCC login call flow. Checked 2026-09-30.
[^18]: EMCC does not support intercom, location-based call admission control (RSVP-based CAC is supported) or IPv6-only phones. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Extension Mobility Cross Cluster Restrictions. Checked 2026-09-30.
[^19]: For EMCC the phone service URL carries an extra parameter: http://<IP Address>:8080/emapp/EMAppServlet?device=#DEVICENAME#&EMCC=#EMCC#. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Configure Extension Mobility > Configure the Cisco Extension Mobility Phone Service (EMCC chapter), Service URL. Checked 2026-09-30.
[^20]: EMCC uses an intercluster SIP trunk whose Trunk Service Type is Extension Mobility Cross Clusters, carrying PSTN access and RSVP agent services. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Configure an Intercluster SIP Trunk for Extension Mobility Cross Cluster. Checked 2026-09-30.
[^21]: Cisco's EMCC task flow, after the phone feature list, is: configure Extension Mobility on both the home and remote clusters, configure certificates, configure devices and templates, configure a geolocation filter, configure EMCC feature parameters, configure an intercluster SIP trunk, configure an intercluster service profile, and configure remote cluster services. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Extension Mobility Cross Cluster Configuration Task Flow table. Checked 2026-09-30.
[^22]: Cisco warns that the remote EMCC cluster must support the minimum TLS version configured on the home cluster. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html), Extension Mobility Cross Cluster, note on minimum TLS version. Checked 2026-09-30.
[^23]: A login attempt fails with error 22 (Dev Logon Disabled) when the Enable Extension Mobility check box is not checked in the Phone Configuration window (Device > Phone) for that phone. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting, Error 22 Dev Logon Disabled. Checked 2026-09-30.
[^24]: Error 201 (Authentication Error) means the user ID or PIN was not accepted; the documented action is to check that the correct user ID and PIN were entered and have the administrator verify them. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting, Error 201 Authentication Error. Checked 2026-09-30.
[^25]: Error 205 (User Profile Absent) means the user has no device profile associated; the fix is to associate a device profile to the user. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting, Error 205 User Profile Absent. Checked 2026-09-30.
[^26]: For an EM Service Connection Error, check that the Cisco Extension Mobility service is running under Tools > Control Center - Feature Services in Cisco Unified Serviceability; for Host Not Found or HTTP 503, check Cisco Tomcat, Cisco IP Phone Services and the Cisco Extension Mobility Application under Tools > Control Center - Network Services. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting, EM Service Connection Error, Host Not Found, HTTP Error (503). Checked 2026-09-30.
[^27]: To find which phones support a feature, open Cisco Unified Reporting, choose System Reports, click Unified CM Phone Feature List, generate a new report or open the existing one, set Product to All, pick the feature name, and click Submit. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Feature Configuration Overview](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_f034b376_00_feature-configuration-overview-12-0.html), Generate a Phone Feature List, steps 1-6. Checked 2026-09-30.
[^28]: The ILS Service in the Extension Mobility service list must be activated on the publisher node. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Activate Extension Mobility Services, note on ILS Service. Checked 2026-09-30.
[^29]: The Unified CM Release 15 feature guide states that Extension Mobility supports IPv6 and can be used with phones whose IP addressing mode is IPv6 or dual-stack (disputed). Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Interactions table, IPv6. Checked 2026-09-30.
[^30]: The Unified CCE 15.0(1) Features Guide states that phones with an IP Addressing Mode of IPv6 Only cannot be used for Cisco Extension Mobility (disputed). Source: [Cisco Unified Contact Center Enterprise Features Guide, Release 15.0(1) - Unified Communications Manager Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/ucce_b_1501_features-guide/rcct_m_1501_unified-communications-manager-extension-mobility.html), Unified Communications Manager Extension Mobility, limitations. Checked 2026-09-30.
[^31]: If the user's locale differs from the phone's locale, the phone restarts and then resets after a successful login because its configuration file is rebuilt; Cisco lists this as expected behaviour needing no action. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Restrictions table, Locale; Troubleshooting, Phone Resets. Checked 2026-09-30.
[^32]: Which phones allow login is decided phone by phone: a phone accepts Extension Mobility logins only if its Enable Extension Mobility check box is checked and it is subscribed to the Extension Mobility service, so leaving either off keeps a phone out of scope (inferred). Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Subscribe to Extension Mobility; Extension Mobility Troubleshooting, Error 22 Dev Logon Disabled and Phone Services Unavailable After Logout. Checked 2026-09-30.
[^33]: If the loginType parameter is left off the service URL, users sign in with User ID and PIN. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Configure the Cisco Extension Mobility Phone Service, step 3, loginType parameter. Checked 2026-09-30.
[^34]: Appending &loginType=DN to the service URL makes users sign in with Primary Extension and PIN, &loginType=SP with Self Service User ID and PIN, and &loginType=UID with User ID and PIN. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Configure the Cisco Extension Mobility Phone Service, step 3, loginType parameter. Checked 2026-09-30.
[^35]: If the Cisco Extension Mobility service is stopped or restarted, users who are already logged in are not logged out automatically when the logout interval expires, and have to be logged out manually from the phone or from administration. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Restrictions table, Log Out. Checked 2026-09-30.
[^36]: After a user logs out, Unified CM sends the logout profile to the phone and restarts the phone. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Overview. Checked 2026-09-30.
[^37]: Maximum Concurrent Requests sets how many login or logout operations can run at once, with a default of 5; error 26 (Busy Please Try Again) indicates concurrent requests above that value. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Maximum Concurrent Requests; Troubleshooting, Error 26. Checked 2026-09-30.
[^38]: Enforce Intra-cluster Maximum Login Time defaults to False, meaning no maximum; set to True, users are logged out automatically after the Intra-cluster Maximum Login Time, which is entered as HHH:MM in the range 0:00 to 168:00 and is ignored while the enforce parameter is False. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Enforce Intra-cluster Maximum Login Time and Intra-cluster Maximum Login Time. Checked 2026-09-30.
[^39]: With Multiple Logins Not Allowed, a user can be logged in to only one device; a login attempt on a second device fails and the phone shows error code 25. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Multiple Login Behavior; Troubleshooting, Error 25 User Logged in Elsewhere. Checked 2026-09-30.
[^40]: The Multiple Login Behavior service parameter has three values, Multiple Logins Allowed, Multiple Logins Not Allowed and Auto Logout, and the default is Multiple Logins Not Allowed. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Multiple Login Behavior. Checked 2026-09-30.
[^41]: Cisco Extension Mobility lets users temporarily access their phone settings, such as line appearances, services and speed dials, from other phones in the system. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Overview, first sentence. Checked 2026-09-30.
[^42]: The Extension Mobility IP phone service is created in Cisco Unified CM Administration at Device > Device Settings > Phone Services: Add New, enter a Service Name and the Service URL, choose in Service Type whether it appears under the Services, Directories or Messages button, and save. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Configure the Cisco Extension Mobility Phone Service, steps 1-5. Checked 2026-09-30.
[^43]: Extension Mobility login requires a physical Cisco Unified IP Phone; users cannot log in to their office phone remotely. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Restrictions table, IP Phones. Checked 2026-09-30.
[^44]: The documented prerequisites for Extension Mobility are a reachable TFTP server and phones that support the feature; Cisco says it extends to most Cisco Unified IP Phones and to check the phone documentation. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Prerequisites. Checked 2026-09-30.
[^45]: When a user logs in and has a user device profile that matches the phone model, the system reconfigures the phone with that user's profile information. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Overview. Checked 2026-09-30.
[^46]: Extension Mobility is disabled on protected phones (the secure tone feature), and Extension Mobility does not support hold reversion. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Restrictions table, Secure Tone and Hold Reversion. Checked 2026-09-30.
[^47]: Remember the Last User Logged In, when True, keeps the last user's ID on the phone and is meant for a phone with only one user; it applies only to the default service URL or a URL with loginType=UID. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Remember the Last User Logged In; Restrictions table, Remember Last User. Checked 2026-09-30.
[^48]: Extension Mobility service parameters are set at System > Service Parameters: choose a node running the Cisco Extension Mobility service, choose the Cisco Extension Mobility service, click Advanced to show all parameters, and save. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Configure Service Parameters for Extension Mobility, steps 1-5. Checked 2026-09-30.
[^49]: The Extension Mobility service URL is case-sensitive, and checking it is one of the first documented troubleshooting steps. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting > Troubleshoot Extension Mobility. Checked 2026-09-30.
[^50]: The Extension Mobility service URL has the form http://<IP Address>:8080/emapp/EMAppServlet?device=#DEVICENAME#, and an IPv6 address is written in square brackets in place of the IP address. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Configure the Cisco Extension Mobility Phone Service, step 3 (Service URL). Checked 2026-09-30.
[^51]: Extension Mobility services are activated in Cisco Unified Serviceability under Tools > Service Activation: select the node, then activate Cisco CallManager, Cisco Tftp, Cisco Extension Mobility and ILS Service, and save. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Activate Extension Mobility Services, steps 1-5. Checked 2026-09-30.
[^52]: To subscribe a phone or a device profile to the Extension Mobility service, open it under Device > Phone or Device > Device Settings > Device Profile, choose Subscribe/Unsubscribe Services from Related Links, click Go, select the Extension Mobility service, click Next, click Subscribe, then save and close the popup. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Subscribe to Extension Mobility, steps 1-7. Checked 2026-09-30.
[^53]: Cisco's Extension Mobility task flow runs in this order: generate a phone feature list, activate Extension Mobility services, configure the Extension Mobility phone service, create a device profile for users, associate the device profile to a user, subscribe to Extension Mobility, configure the Change Credential phone service, and optionally configure service parameters. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Configuration Task Flow table. Checked 2026-09-30.
[^54]: Extension Mobility debug tracing is enabled in Cisco Unified Serviceability under Trace > Trace Configuration by selecting Cisco Extension Mobility from the configured services. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting > Troubleshoot Extension Mobility. Checked 2026-09-30.
[^55]: For Unified CCE agents on hard phones using Extension Mobility only, Cisco recommends setting Multiple Login Behavior to Auto Logout; for mixed environments or EMCC it recommends setting the maximum login time to the typical agent shift length. Source: [Cisco Unified Contact Center Enterprise Features Guide, Release 15.0(1) - Unified Communications Manager Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/ucce_b_1501_features-guide/rcct_m_1501_unified-communications-manager-extension-mobility.html), Unified Communications Manager Extension Mobility, limitations and recommended settings. Checked 2026-09-30.
[^56]: In Unified CCE, if an agent fails to log out of an Extension Mobility device, another agent who tries to use that device gets a shared line error. Source: [Cisco Unified Contact Center Enterprise Features Guide, Release 15.0(1) - Unified Communications Manager Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/ucce_b_1501_features-guide/rcct_m_1501_unified-communications-manager-extension-mobility.html), Unified Communications Manager Extension Mobility, limitations. Checked 2026-09-30.
[^57]: If phone services disappear after login, the user's device profile had no services associated and needs the Extension Mobility service; if they disappear after logout, the phone itself needs to be subscribed to the Extension Mobility service. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting, Phone Services Unavailable After Login / After Logout. Checked 2026-09-30.
[^58]: If users are logged in when the publisher switches version during an upgrade and the publisher becomes inactive, their Extension Mobility profiles are logged out and they must log in again once Unified CM is active. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Troubleshooting, Extension Mobility Performance During Upgrade. Checked 2026-09-30.
[^59]: Validate IP Address, when True, checks the source IP of each login or logout request against the device cache and the Trusted List of IPs (semicolon-separated, up to 1024 characters); Allow Proxy permits requests through a web proxy and requires Validate IP Address to be True. Source: [Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e8ed1830_00_extension-mobility-12-0.html), Extension Mobility Service Parameters table, Validate IP Address, Trusted List of IPs, Allow Proxy. Checked 2026-09-30.
[^60]: Version 15 is the latest Cisco Unified Communications Manager major release listed on Cisco's support pages; it was released on 16 October 2023 and its status is Available. Source: [Cisco Unified Communications Manager (CallManager) - Support](https://www.cisco.com/c/en/us/support/unified-communications/unified-communications-manager-callmanager/series.html), Product status and Latest release fields; Supported versions list. Checked 2026-09-30.