# Troubleshooting Extension Mobility login failures in Unified CM Canonical: https://warmtransfer.net/knowledge/cucm-extension-mobility-troubleshooting Last verified: 2026-10-02 In Unified CM 15, Extension Mobility login failures appear on the phone as numbered errors, for example Error 201 Authentication Error when the user ID or PIN entered was not accepted, and Error 22 Dev Logon Disabled when the Enable Extension Mobility check box is not checked in the Phone Configuration window[^26][^32]. In Unified CM 15 EMCC, failures appear as Login is unavailable with a numeric code, for example 31 when EMCC is not activated for the user and 38 when the home cluster does not allow EMCC login[^12][^16]. ## Configuration that login depends on The Unified CM 15 Extension Mobility task flow requires activating Cisco CallManager, Cisco Tftp and Cisco Extension Mobility in Service Activation, plus the ILS Service on the publisher node only[^53]. The documented Extension Mobility phone service URL in Unified CM 15 is `http://:8080/emapp/EMAppServlet?device=#DEVICENAME#`[^52]. The documented Secure-Service URL in Unified CM 15 is `https://:8443/emapp/EMAppServlet?device=#DEVICENAME#`[^50]. Cisco's Unified CM 12.5(1) Troubleshooting Guide warns that the Cisco Extension Mobility service URL is case sensitive[^59]. From Unified CM 12.x, the service URL accepts an optional loginType parameter: UID (user ID and PIN, the default), DN (primary extension and PIN) or SP (self-service user ID and PIN)[^43]. In Unified CM 15, both the phones and the Extension Mobility device profiles must be subscribed to the Extension Mobility phone service, through Related Links > Subscribe/Unsubscribe Services[^54]. Cisco directs administrators to run the Generate Phone Feature List report to confirm that a Cisco IP Phone model supports Extension Mobility in Unified CM 15[^38]. When the Unified CM 15 Alphanumeric User ID service parameter is True, the case-sensitive user ID field requires lowercase characters[^1]. In Unified CM 15, Cisco Extension Mobility caches logged-in user information for 2 minutes[^5]. ## Diagnosing intra-cluster login errors | Phone message | Documented cause | |---|---| | Error 201 Authentication Error | The user ID or PIN entered was not accepted[^26] | | Error 202 Blank User ID or PIN | The user ID or PIN field was left empty[^27] | | Error 205 User Profile Absent | No device profile is associated with the end user[^28] | | Error 207 Device Name Empty | The Extension Mobility service URL is wrong, for example the device=#DEVICENAME# parameter is missing or malformed[^29] | | Error 22 Dev Logon Disabled | Enable Extension Mobility is not checked in the Phone Configuration window of the phone being used[^32] | | Error 25 User Logged in Elsewhere | The user is logged in on another phone and Multiple Login Behavior does not allow multiple logins[^34] | | Error 26 Busy Please Try Again | Simultaneous login or logout requests exceeded the Maximum Concurrent Requests service parameter[^35] | | Error 6 Database Error | A high volume of requests[^37] | | Login is unavailable(23) | The entered user ID, self-service user ID or primary extension, depending on loginType, was not found in the database[^33] | For Error 201, the documented fix is to confirm the correct user ID and PIN with the administrator[^26]. For Error 202, the documented fix is to enter a valid user ID and PIN[^27]. For Error 205, the documented fix is to associate a device profile to the user[^28]. For Error 207, the documented fix is to verify the configured service URL[^29]. WarmTransfer's reading of the sources is that, because Cisco documents Error 207 both as Device Name Empty and, in the Release 15 guide, as EM Service Connection Error, a 207 on a Release 15 phone should be checked against both the service URL and the state of the Cisco Extension Mobility service[^41]. For Error 6, Cisco advises checking the Extension Mobility performance counters and database logs[^37]. Error 26 is tied to the Maximum Concurrent Requests service parameter[^35]. The Unified CM 15 Extension Mobility Maximum Concurrent Requests service parameter defaults to 5, which Cisco describes as acceptable in most cases[^45]. ## Service and connection errors In Unified CM 15, a Host Not Found message on the phone when invoking Extension Mobility points to the Cisco Tomcat service, and Cisco advises checking that Cisco Tomcat is running[^39]. When the phone shows HTTP Error (503) while using Extension Mobility in Unified CM 15, the Cisco IP Phone Services or Cisco Extension Mobility Application service should be checked to confirm it is running[^40]. ## Problems after login or logout In Unified CM 15, if phone services are unavailable after a user logs in with Extension Mobility, the user's device profile must be subscribed to the Cisco Extension Mobility service[^55]. If phone services are unavailable after logout, the Unified CM 15 fix is to subscribe the phone itself to the Cisco Extension Mobility service[^56]. For problems after login or logout, the 12.5(1) Troubleshooting Guide says to check that the enterprise parameter Synchronization Between Auto Device Profile and Phone Configuration is True and that the phone is subscribed to the Extension Mobility service[^57]. In Unified CM 15, a phone that resets instead of just restarting after login or logout is expected when the user profile locale differs from the phone locale, and no action is required[^49]. ## Multiple login behaviour The Unified CM 15 Multiple Login Behavior service parameter has 3 values: Multiple Logins Allowed, Multiple Logins Not Allowed (a second login fails with error 25) and Auto Logout (the first device is logged out when the user logs in on a second)[^48]. Unified CM 12.5 added Multiple Login Behavior control for EMCC; before 12.5, multiple EMCC logins were always allowed and administrators could not control it[^21]. For EMCC from Unified CM 12.5, the Multiple Login Behavior setting of the home cluster is enforced, not that of the visiting cluster[^18]. From Unified CM 12.5, the Extension Mobility service logs show the Multi Login Policy as multiOK, noLogin or autoLogout, and a blocked login shows the message Not allowed to log into multiple devices[^47]. ## Automatic logout not occurring In Unified CM 15, intra-cluster automatic logout occurs only when the Enforce Intra-cluster Maximum Login Time service parameter is True and a valid Intra-cluster Maximum Login Time is set[^3]. The Intra-cluster Maximum Login Time parameter takes HHH:MM values from 0:00 to 168:00 and is ignored when Enforce Intra-cluster Maximum Login Time is False[^46]. In Unified CM 15, if the Cisco Extension Mobility service is stopped or restarted, users are not automatically logged out when their logout interval expires, and those phones log out once a day instead[^4]. We infer that when auto logout is not firing, the 2 documented causes to check first are that Enforce Intra-cluster Maximum Login Time is not True and that the Cisco Extension Mobility service was restarted after the users logged in[^42]. ## Diagnosing EMCC login errors | Phone message | Documented cause | |---|---| | Login is unavailable(1) | A parsing error where EMService cannot parse the XML request, often because of a version mismatch between clusters[^8] | | Login is unavailable(28) | In Unified CM 15 EMCC, Validate IP Address is enabled and the requesting IP address is not in the trusted list[^11] | | Login is unavailable(31) | In Unified CM 15 EMCC, Enable Extension Mobility Cross Cluster is not checked on the end user[^12] | | Login is unavailable(35) | In Unified CM 15 EMCC, the visiting cluster is not configured as a remote cluster on the home cluster[^13] | | Login is unavailable(36) | In Unified CM 15 EMCC, the administrator has not added any remote cluster[^14] | | Error 37 (Duplicate Device Name) | In Unified CM 15 EMCC, the same device name exists in both the home and visiting clusters[^15] | | Login is unavailable(38) | In Unified CM 15 EMCC, the home cluster does not allow EMCC login[^16] | | Error 47 (DN has multiple users) | An EMCC login by primary extension where that extension is assigned to more than one user[^36] | | Login is unavailable(213) | In Unified CM 15 EMCC, the phone model does not support EMCC[^10] | In Unified CM 15 EMCC, for error 37, Cisco recommends disabling autoregistration on all nodes so a new device is not created in the home cluster after EMCC logout[^15]. In Unified CM 15, if the EM service on one cluster gets no reply from a remote cluster within the update interval, Remote Activated is set to False and visiting phones may fail with Login is unavailable[^23]. In Unified CM 15, phones with IPv6-only addressing cannot use EMCC, and IPv4 or dual-stack addressing is required[^19]. After a successful EMCC login, the phone unregisters from the visiting cluster and registers to a call-processing node of the home cluster[^22]. ## Traces and logs to collect To trace Extension Mobility, choose Trace > Trace Configuration in Cisco Unified Serviceability, select the server, and choose Cisco Extension Mobility from Configured Services to enable debug tracing[^58]. On Unified CM 14.0.1.12900-161, the Cisco Extension Mobility service logs are at `activelog /tomcat/logs/em/log4j/emservice*.log`[^25]. On the same release, the Cisco Extension Mobility Application logs are at `activelog /tomcat/logs/em/log4j/emapp*.log`[^6]. For EM and EMCC login or logout problems, Cisco TAC lists these logs to collect: Cisco Extension Mobility, Cisco Extension Mobility Application, phone console logs, a packet capture from the phone and detailed TVS logs[^44]. For EMCC problems, Cisco TAC asks for Cisco CallManager, Cisco Extension Mobility, Cisco Extension Mobility Application, Cisco TFTP and Cisco Trust Verification Service logs from all nodes of each cluster, plus user ID, phone MAC, phone IP and timestamp[^20]. ## See also - [Unified CM Extension Mobility and cross-cluster Extension Mobility](https://warmtransfer.net/knowledge/cucm-extension-mobility) - [Setting up Extension Mobility in Unified CM](https://warmtransfer.net/knowledge/cucm-extension-mobility-setup) - [Unified CM release trains and lifecycle dates](https://warmtransfer.net/knowledge/cucm-versions-lifecycle) ## Applicability Applies to: Cisco Unified Communications Manager. Deployments: on-premises. Sources checked 2026-10-02. The error, service URL, service activation, subscription and service parameter details in this article come from Cisco's Feature Configuration Guide for Unified CM Release 15 and SUs[^26][^52][^53]. The loginType parameter is documented from Unified CM 12.x[^43]. Login is unavailable(23) and error 47 are documented from Unified CM 12.x[^33][^36]. EMCC Multiple Login Behavior control and its log values apply from Unified CM 12.5[^21][^47]. The trace configuration steps, the case-sensitivity warning and the Synchronization Between Auto Device Profile and Phone Configuration check come from the Unified CM 12.5(1) Troubleshooting Guide[^58][^59][^57]. The log file paths are documented for Unified CM 14.0.1.12900-161[^25][^6]. ## What remains uncertain The meaning of Error 207 on Release 15 is documented two ways, and WarmTransfer's reading of the sources is that both the service URL and the Cisco Extension Mobility service state should be checked[^41]. Whether the Extension Mobility log file paths documented for 14.0.1.12900-161 are unchanged in Release 15 is not covered by the sources below. The permitted range of the Maximum Concurrent Requests service parameter, beyond its documented default, is not covered by the sources below. Whether an intra-cluster login using loginType DN reports the same error as the EMCC error 47 when an extension is shared by several users is not covered by the sources below. ## Sources [^1]: When the Unified CM 15 Alphanumeric User ID service parameter is True, the case-sensitive user ID field requires lowercase characters. 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 > Alphanumeric User ID. Checked 2026-10-02. [^2]: In Unified CM 15, associating a device profile with a user means moving it from Available Profiles to Controlled Profiles in the End User window and checking the Home Cluster check box. 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 Device Profile to User. Checked 2026-10-02. [^3]: In Unified CM 15, intra-cluster Extension Mobility automatic logout occurs only when the Enforce Intra-cluster Maximum Login Time service parameter is True and a valid Intra-cluster Maximum Login Time is set. 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 > Enforce Intra-cluster Maximum Login Time; Intra-cluster Maximum Login Time. Checked 2026-10-02. [^4]: In Unified CM 15, if the Cisco Extension Mobility service is stopped or restarted, users are not automatically logged out when their logout interval expires; those phones log out once a day instead. 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 / automatic logout note. Checked 2026-10-02. [^5]: In Unified CM 15, Cisco Extension Mobility caches logged-in user information for 2 minutes. 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 (cache). Checked 2026-10-02. [^6]: On Unified CM 14.0.1.12900-161, the Cisco Extension Mobility Application logs are at activelog /tomcat/logs/em/log4j/emapp*.log. Source: [Troubleshoot Trace Locations in CLI for CUCM 14](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/220309-troubleshoot-trace-locations-in-cli-for.html), Trace location table > Cisco Extension Mobility Application. Checked 2026-10-02. [^7]: In Unified CM 15, disabling EMCC does not automatically log out users who already have EMCC sessions; they must be logged out manually. 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 (logout). Checked 2026-10-02. [^8]: In Unified CM EMCC, Login is unavailable(1) is a parsing error where EMService cannot parse the XML request, often because of a version mismatch between clusters. 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), Troubleshooting Extension Mobility Cross Cluster > service error codes, row 1. Checked 2026-10-02. [^9]: In Unified CM 15 EMCC, Login is unavailable(211) (EMCC Not Activated) is tied to PSTN access not being activated in the Intercluster Service Profile. 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), Troubleshooting Extension Mobility Cross Cluster > application error codes, row 211. Checked 2026-10-02. [^10]: In Unified CM 15 EMCC, Login is unavailable(213) means the phone model does not support 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), Troubleshooting Extension Mobility Cross Cluster > application error codes, row 213. Checked 2026-10-02. [^11]: In Unified CM 15 EMCC, Login is unavailable(28) (Untrusted IP Error) occurs when Validate IP Address is enabled and the requesting IP address is not in the trusted list. 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), Troubleshooting Extension Mobility Cross Cluster > service error codes, row 28. Checked 2026-10-02. [^12]: In Unified CM 15 EMCC, Login is unavailable(31) means EMCC is not activated for the user, because Enable Extension Mobility Cross Cluster is not checked on the end user. 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), Troubleshooting Extension Mobility Cross Cluster > application error codes, row 31. Checked 2026-10-02. [^13]: In Unified CM 15 EMCC, Login is unavailable(35) means the visiting cluster is not configured as a remote cluster 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), Troubleshooting Extension Mobility Cross Cluster > application error codes, row 35. Checked 2026-10-02. [^14]: In Unified CM 15 EMCC, Login is unavailable(36) (No Remote Cluster) means the administrator has not added any remote 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), Troubleshooting Extension Mobility Cross Cluster > application error codes, row 36. Checked 2026-10-02. [^15]: In Unified CM 15 EMCC, error 37 (Duplicate Device Name) occurs when the same device name exists in both the home and visiting clusters; Cisco recommends disabling autoregistration on all nodes so a new device is not created in the home cluster after EMCC logout. 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 (duplicate device); error code table row 37. Checked 2026-10-02. [^16]: In Unified CM 15 EMCC, Login is unavailable(38) (EMCC Not Allowed) means the home cluster does not allow EMCC login. 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), Troubleshooting Extension Mobility Cross Cluster > application error codes, row 38. Checked 2026-10-02. [^17]: In Unified CM 15 EMCC, error 43 is a device security mode error, resolved by setting the EMCC device security profile to Nonsecure. 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), Troubleshooting Extension Mobility Cross Cluster > application error codes, row 43. Checked 2026-10-02. [^18]: For EMCC from Unified CM 12.5, the Multiple Login Behavior setting of the home cluster is enforced, not that of the visiting cluster. 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), Configuration / enforcement note. Checked 2026-10-02. [^19]: In Unified CM 15, phones with IPv6-only addressing cannot use EMCC; IPv4 or dual-stack addressing is required. 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 (IPv6). Checked 2026-10-02. [^20]: For EMCC problems, Cisco TAC asks for Cisco CallManager, Cisco Extension Mobility, Cisco Extension Mobility Application, Cisco TFTP and Cisco Trust Verification Service logs from all nodes of each cluster, plus user ID, phone MAC, phone IP and timestamp. 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), Data to collect. Checked 2026-10-02. [^21]: Unified CM 12.5 added Multiple Login Behavior control for EMCC; before 12.5, multiple EMCC logins were always allowed and administrators could not control it. 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), Introduction / Main Service Parameter change. Checked 2026-10-02. [^22]: After a successful EMCC login, the phone unregisters from the visiting cluster and registers to a call-processing node of 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), Log analysis walkthrough (phone registration to home cluster). Checked 2026-10-02. [^23]: In Unified CM 15, if the EM service on one cluster gets no reply from a remote cluster within the update interval, Remote Activated is set to False and visiting phones may fail with Login is unavailable. 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 (Remote Activated). Checked 2026-10-02. [^24]: In Unified CM 15, a secure EMCC login fails when the home cluster is nonsecure and the visiting cluster is in mixed (secure) 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 Restrictions (security mode). Checked 2026-10-02. [^25]: On Unified CM 14.0.1.12900-161, the Cisco Extension Mobility service logs are at activelog /tomcat/logs/em/log4j/emservice*.log. Source: [Troubleshoot Trace Locations in CLI for CUCM 14](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/220309-troubleshoot-trace-locations-in-cli-for.html), Trace location table > Cisco Extension Mobility. Checked 2026-10-02. [^26]: In Unified CM 15, Error 201 Authentication Error on the phone during Extension Mobility login means the user ID or PIN entered was not accepted; the fix is to confirm the correct user ID and PIN with the administrator. 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), Troubleshooting Extension Mobility > Authentication Error. Checked 2026-10-02. [^27]: In Unified CM 15, Error 202 Blank User ID or PIN appears when the user ID or PIN field was left empty; the fix is to enter a valid 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), Troubleshooting Extension Mobility > Blank User ID or PIN. Checked 2026-10-02. [^28]: In Unified CM 15, Error 205 User Profile Absent means no device profile is associated with the end user; 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), Troubleshooting Extension Mobility > User Profile Absent. Checked 2026-10-02. [^29]: In Unified CM, Error 207 Device Name Empty indicates the Extension Mobility service URL is wrong (for example the device=#DEVICENAME# parameter is missing or malformed); the fix is to verify the configured service URL. 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), Troubleshooting Extension Mobility > Device Name Empty. Checked 2026-10-02. [^30]: The Unified CM 15 Feature Configuration Guide labels the phone message EM Service Connection Error as Error 207 and says to verify that the Cisco Extension Mobility service is running (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), Troubleshooting Extension Mobility > EM Service Connection Error. Checked 2026-10-02. [^31]: The Unified CM 12.5(1) Troubleshooting Guide lists Error 208 as the Extension Mobility Service connection error and says to verify that the Cisco Extension Mobility service is running (disputed). Source: [Troubleshooting Guide for Cisco Unified Communications Manager, Release 12.5(1) - Troubleshooting Features and Services](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/trouble/12_5_1/cucm_b_troubleshooting-guide-1251/cucm_b_troubleshooting-guide-1251_chapter_01000.html), Cisco Extension Mobility > error code table, row 208. Checked 2026-10-02. [^32]: In Unified CM 15, Error 22 Dev Logon Disabled means the Enable Extension Mobility check box is not checked in the Phone Configuration window of the phone being used. 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), Troubleshooting Extension Mobility > Dev Logon Disabled. Checked 2026-10-02. [^33]: From Unified CM 12.x, Login is unavailable(23) means the entered user ID, self-service user ID or primary extension (depending on loginType) was not found in the database. Source: [CUCM 12.X Extension Mobility (EM) and Extension Mobility Cross Cluster (EMCC) Log in service URL](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/212083-CUCM-12-X-Extension-Mobility-EM-and-Ext.html), Troubleshoot / error code 23. Checked 2026-10-02. [^34]: In Unified CM 15, Error 25 User Logged in Elsewhere appears when the user is already logged in on another phone and the Multiple Login Behavior service parameter does not allow multiple logins. 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), Troubleshooting Extension Mobility > User Logged in Elsewhere; Service Parameters table > Multiple Login Behavior. Checked 2026-10-02. [^35]: In Unified CM 15, Error 26 Busy Please Try Again means the number of simultaneous login or logout requests exceeded the Maximum Concurrent Requests service parameter. 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), Troubleshooting Extension Mobility > Busy Please Try Again. Checked 2026-10-02. [^36]: From Unified CM 12.x, error 47 (DN has multiple users) appears on an EMCC login by primary extension when that extension is assigned to more than one user. Source: [CUCM 12.X Extension Mobility (EM) and Extension Mobility Cross Cluster (EMCC) Log in service URL](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/212083-CUCM-12-X-Extension-Mobility-EM-and-Ext.html), Troubleshoot / error code 47. Checked 2026-10-02. [^37]: In Unified CM 15, Error 6 Database Error on Extension Mobility login points to a high volume of requests; Cisco advises checking the Extension Mobility performance counters and database logs. 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), Troubleshooting Extension Mobility > Database Error. Checked 2026-10-02. [^38]: Cisco directs administrators to run the Generate Phone Feature List report to confirm that a Cisco IP Phone model supports Extension Mobility in Unified CM 15. 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 Task Flow > Generate a Phone Feature List. Checked 2026-10-02. [^39]: In Unified CM 15, a Host Not Found message on the phone when invoking Extension Mobility points to the Cisco Tomcat service; Cisco advises checking that Cisco Tomcat is running. 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), Troubleshooting Extension Mobility > Host Not Found. Checked 2026-10-02. [^40]: In Unified CM 15, an HTTP Error (503) on the phone when using Extension Mobility means the Cisco IP Phone Services or Cisco Extension Mobility Application service should be checked to confirm it is running. 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), Troubleshooting Extension Mobility > HTTP Error. Checked 2026-10-02. [^41]: Because Cisco documents Error 207 both as Device Name Empty (wrong URL) and, in the Release 15 guide, as EM Service Connection Error, a 207 on a Release 15 phone should be checked against both the service URL and the state of the Cisco Extension Mobility service (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), Troubleshooting Extension Mobility > Device Name Empty; EM Service Connection Error. Checked 2026-10-02. [^42]: When EM auto logout is not firing, the two documented causes to check first are that Enforce Intra-cluster Maximum Login Time is not True, and that the Cisco Extension Mobility service was restarted after the users logged in (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), Configure Service Parameters > Enforce Intra-cluster Maximum Login Time; automatic logout restriction note. Checked 2026-10-02. [^43]: From Unified CM 12.x, the Extension Mobility service URL accepts an optional loginType parameter: UID (user ID and PIN, the default), DN (primary extension and PIN) or SP (self-service 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 Extension Mobility Phone Service > Service URL (loginType options). Checked 2026-10-02. [^44]: For EM and EMCC login or logout problems, Cisco TAC lists these logs to collect: Cisco Extension Mobility, Cisco Extension Mobility Application, phone console logs, a packet capture from the phone and detailed TVS logs. Source: [CUCM 12.X Extension Mobility (EM) and Extension Mobility Cross Cluster (EMCC) Log in service URL](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/212083-CUCM-12-X-Extension-Mobility-EM-and-Ext.html), Logs to collect. Checked 2026-10-02. [^45]: The Unified CM 15 Extension Mobility Maximum Concurrent Requests service parameter defaults to 5, which Cisco describes as acceptable in most cases. 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 > Maximum Concurrent Requests. Checked 2026-10-02. [^46]: The Unified CM 15 Intra-cluster Maximum Login Time parameter takes HHH:MM values from 0:00 to 168:00 and is ignored when Enforce Intra-cluster Maximum Login Time 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), Configure Service Parameters > Intra-cluster Maximum Login Time. Checked 2026-10-02. [^47]: From Unified CM 12.5, the Extension Mobility service logs show the Multi Login Policy as multiOK, noLogin or autoLogout, and a blocked login shows the message Not allowed to log into multiple devices. 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), Verify / log snippets. Checked 2026-10-02. [^48]: The Unified CM 15 Multiple Login Behavior service parameter has three values: Multiple Logins Allowed, Multiple Logins Not Allowed (a second login fails with error 25) and Auto Logout (the first device is logged out when the user logs in on a second). 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 > Multiple Login Behavior. Checked 2026-10-02. [^49]: In Unified CM 15, a phone that resets instead of just restarting after Extension Mobility login or logout is expected when the user profile locale differs from the phone locale, and no action is required. 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), Troubleshooting Extension Mobility > Phone Resets. Checked 2026-10-02. [^50]: The documented Secure-Service URL for the Extension Mobility phone service in Unified CM 15 is https://:8443/emapp/EMAppServlet?device=#DEVICENAME#. 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 Extension Mobility Phone Service > Secure-Service URL. Checked 2026-10-02. [^51]: In Unified CM 15, a user's self-service (Self Care) Extension Mobility maximum login time setting, when enabled, overrides the service-parameter maximum login 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), Configure Service Parameters > note under Intra-cluster Maximum Login Time. Checked 2026-10-02. [^52]: The documented Extension Mobility phone service URL in Unified CM 15 is http://:8080/emapp/EMAppServlet?device=#DEVICENAME#. 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 Extension Mobility Phone Service > Service URL. Checked 2026-10-02. [^53]: The Unified CM 15 Extension Mobility task flow requires activating Cisco CallManager, Cisco Tftp and Cisco Extension Mobility in Service Activation, plus the ILS Service on the publisher node only. 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. Checked 2026-10-02. [^54]: In Unified CM 15, both the phones and the Extension Mobility device profiles must be subscribed to the Extension Mobility phone service (Related Links > 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), Subscribe to Extension Mobility Service. Checked 2026-10-02. [^55]: In Unified CM 15, if phone services are unavailable after a user logs in with Extension Mobility, the user's device profile must include (be subscribed to) the Cisco 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), Troubleshooting Extension Mobility > Phone Services Unavailable After Login. Checked 2026-10-02. [^56]: In Unified CM 15, if phone services are unavailable after Extension Mobility logout, the fix is to subscribe the phone itself to the Cisco 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), Troubleshooting Extension Mobility > Phone Services Unavailable After Logout. Checked 2026-10-02. [^57]: For problems after EM login or logout, the 12.5(1) Troubleshooting Guide says to check that the enterprise parameter Synchronization Between Auto Device Profile and Phone Configuration is True and that the phone is subscribed to the Extension Mobility service. Source: [Troubleshooting Guide for Cisco Unified Communications Manager, Release 12.5(1) - Troubleshooting Features and Services](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/trouble/12_5_1/cucm_b_troubleshooting-guide-1251/cucm_b_troubleshooting-guide-1251_chapter_01000.html), Cisco Extension Mobility > login/logout problems. Checked 2026-10-02. [^58]: To trace Extension Mobility, choose Trace > Trace Configuration in Cisco Unified Serviceability, select the server, and choose Cisco Extension Mobility from Configured Services to enable debug tracing. Source: [Troubleshooting Guide for Cisco Unified Communications Manager, Release 12.5(1) - Troubleshooting Features and Services](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/trouble/12_5_1/cucm_b_troubleshooting-guide-1251/cucm_b_troubleshooting-guide-1251_chapter_01000.html), Cisco Extension Mobility > Troubleshooting steps. Checked 2026-10-02. [^59]: Cisco's Unified CM 12.5(1) Troubleshooting Guide warns that the Cisco Extension Mobility service URL is case sensitive. Source: [Troubleshooting Guide for Cisco Unified Communications Manager, Release 12.5(1) - Troubleshooting Features and Services](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/trouble/12_5_1/cucm_b_troubleshooting-guide-1251/cucm_b_troubleshooting-guide-1251_chapter_01000.html), Cisco Extension Mobility > Troubleshooting steps. Checked 2026-10-02.