# Troubleshooting UCCE and CVP call failures Canonical: https://warmtransfer.net/knowledge/cvp-call-failures-troubleshooting Last verified: 2026-10-02 Cisco's technote on CVP SendToVRU and Run External Script failures requires a Type 10 network VRU with a label for every CVP PG, and it requires the VRU label length to match the Maximum Length of DNIS configured on CVP[^50][^52]. When a routing script cannot find a destination, UCCE uses the default label associated with the dialed number, and if no default label is defined, it returns an error to the routing client[^44][^34]. ## How the VRU leg is built In the comprehensive model, CVP needs a Type 10 network VRU with 1 label per Unified CVP Call Server or NIC routing client[^27]. See also [Setting up a CVP comprehensive call flow in UCCE](https://warmtransfer.net/knowledge/cvp-comprehensive-call-flow-setup). For the comprehensive model, CVP's Maximum Length of DNIS is set to the length of the network routing number[^29]. With a gateway pattern of 1800 followed by 6 digits, that length is 10[^29]. CVP routes a returned label either through Local Static Routes in the Dialed Number Pattern configuration or through a SIP proxy server with static routes for the pattern[^28]. UCCE selects a call type for a voice call from the dialed number, caller-entered digits (CED) and calling line ID (CLID)[^1]. When no call type matches, UCCE uses the routing client's default call type[^5]. If the routing client has no default call type, UCCE uses the general default call type[^5]. If the routing client's timeout limit is reached before any on-time routing responses arrive, the NIC tells the routing client to stop sending routing requests[^35]. See also [Troubleshooting UCCE calls that do not route to agents](https://warmtransfer.net/knowledge/ucce-calls-not-routing-troubleshooting). ## Diagnosing SendToVRU and Run External Script failures WarmTransfer's reading of the sources is that a failed VRU leg can break at 3 separable points (the router finding a VRU label, CVP routing the label plus correlation ID, and the VXML gateway matching a dial-peer with the right application), and each point leaves evidence in a different log[^53]. ### The router cannot find a VRU label - **"Customer not found for dialed number... using default"**: the dialed number has no customer instance assigned. Cisco's resolution is to define a customer instance for every dialed number rather than rely on the default[^12]. - **"Customer (n) has no valid network vru defined - using default"**: the customer instance is not associated with a network VRU. The fix is to associate it with a valid network VRU[^11]. - **"No label configured on network VRU... for routing client..."**: the Type 10 network VRU lacks a label for that routing client. The fix is to add a VRU label for each routing client[^13]. - **"No NetworkVRU configured for peripheral for VRU capable call on dialed number"**: the CVP PG peripheral has no Type 10 network VRU assigned[^14]. See also [Troubleshooting UCCE peripheral gateways and CTI Server going offline](https://warmtransfer.net/knowledge/ucce-peripheral-gateway-troubleshooting). ### CVP cannot route the VRU label A CVP log message that the B2BUA is not configured with a route for the label-plus-correlation-ID number means CVP has no static route and no proxy route that matches the VRU label toward the VXML gateway[^10]. ### The VXML gateway does not run the VRU script A VRU leg that reaches the VXML gateway but matches a default dial-peer instead of the VRU dial-peer fails to run the VRU script[^58]. Causes include no VRU dial-peer, a pattern that does not match the DNIS, or a missing signature digit[^58]. If the VRU dial-peer has no application bound, the gateway hands the call to the default application[^57]. The IOS VXML gateway needs the TCL bootstrap application with the cvphost parameter set and header-passing enabled[^57]. ### ECC variable errors The Call Server log message "VRU APPLICATION ERROR: Assigning the tag 7 to the non-existing ECC variable" means the ECC variable is missing in ICM/NAM or is defined with different lengths[^51]. The fix is an identical ECC definition[^51]. ## Traces and logs ### Router tracing For SendToVRU failures, Cisco's technote enables router tracing for Route Request, Script Selects, Network VRU Tracing and Call Queuing, and enables CVP Debug41[^25]. In UCCE 15.0(1), Router trace levels are 0x00 (default/error), 0x0F (warning), 0xFF (informational) and 0xFFF (debug)[^42]. Router tracing above default captures Route Requests, Network VRU, Trans Route, VRU Bank, CIC Request, Script Select, Call Queuing, Agent changes and Call Type Real Time[^41]. Router tracing can be set with RTRTRACE, RTTEST or the System CLI, and RTRTRACE settings take effect immediately[^43]. The router process must be running before router tracing can be set or router traces retrieved, whatever tool is used[^40]. ### Reading UCCE logs with dumplog UCCE process trace logs are stored under `[Drive]:\icm\\\logfiles` as.ems files[^24]. Given only a process prefix such as rtr, dumplog dumps the current day's log for that process unless dates or times are specified[^6]. - **Limit by time**: `/bd` and `/ed` take dates (mm/dd/yyyy), `/bt` and `/et` take times (hh:mm:ss), and `/hr` takes a number of hours back[^8]. - **Write to a file**: `/of`[^8]. - **Filter lines**: `/m` keeps only lines matching a string, and `/x` excludes a string[^7]. - **Add milliseconds**: `/ms`[^7]. - **Select a log file**: `/last` selects the most recent log file, and `/prev` selects the previous one[^7]. ### CVP Call Server and VXML Server logs CVP Call Server logs are in `C:\Cisco\CVP\logs` by default, and the file to collect is the one covering the time of the failure[^2]. To get SIP message detail, set com.dynamicsoft.DsLibs.DsUALibs to DEBUG on the CVP Call Server diag page (port 8000, /cvp/diag)[^3]. Restore the previous level after reproducing the failure[^3]. Since CVP 8.0(1), VXML Server receives callid (the call GUID), _dnis and _ani by default, and these values appear in the VXML Server log[^55]. The callid value links Call Server logs to VXML Server logs[^55]. VXML Server global call and error logs are written daily under `%CVP_HOME%\VXMLServer\logs\GlobalCallLogger` and `GlobalErrorLogger`[^56]. The VXML Server application error logger records Java exceptions (optionally with stack traces), application timeouts and errors from other loggers in that application[^54]. ### IOS gateway debugs For VRU-leg failures, Cisco lists these IOS gateway debugs: `debug voip ccapi inout`, `debug ccsip message`, `debug voip application vxml`, `debug voip application tcl commands` and `debug http msg`[^4]. ## Script error checking CVP reports micro-application problems in the user.microapp.error_code ECC variable, which is usually set when control leaves the X (failure) branch[^9]. Cisco advises testing this variable after every X branch[^9]. | Value | Meaning | |---|---| | 0 to 3 | No error, caller hangup, network error and system error, in that order[^30] | | 5 | Unknown micro-application[^33] | | 16 | Caller reached the maximum number of invalid tries[^31] | | 31 | ASR error[^32] | | 32 | TTS error[^32] | ## SIP server group heartbeats A CVP SIP server group lets the originating endpoint know the destination's status before it sends the INVITE, so failed endpoints are skipped faster[^45]. CVP server groups are not added automatically and must be configured explicitly[^46]. At least 1 Call Server must exist before the server group settings can be saved[^46]. A server group can send heartbeats only to the endpoints defined in it[^47]. CVP SIP server group heartbeats use the SIP OPTIONS method as a ping to learn endpoint status without placing a call[^23]. See also [SIP OPTIONS pings and trunk keepalives](https://warmtransfer.net/knowledge/sip-options-keepalive). The CVP 12.5(1) configuration guide gives the following heartbeat defaults[^19][^21][^16]: - **Heartbeat Local Listen Port**: 5067[^19]. - **Heartbeat SIP Method**: OPTIONS, with PING as the alternative[^19]. - **Heartbeat Transport Type**: UDP, with TCP as the alternative[^19]. - **Heartbeat Timeout**: 500 ms, with a range of 100 through 3000 ms[^21]. - **Up and Down Endpoint Heartbeat Interval**: both default to 5000 ms, with a range of 5000 through 3600000 ms[^16]. - **Overloaded Response Codes**: 503, 480 and 600[^18]. This is disputed: the CVP 12.5(1) configuration guide gives a default of 1 for Number of failed Heartbeats for unreachable status, with a range of 1 through 5[^15]. CVP keeps failed destinations in an unreachable destination table, and the DsUnreachableDestinationTableTimer default is 180 seconds[^22]. Heartbeat state changes appear in CVP logs as UnreachableDestinationTable add and remove entries and as endpointUnreachableClear events[^17]. ## Failover and survivability - **IVR Service failure**: in CVP 15.0(1), calls in progress are default-routed to an alternate location on the originating gateway[^26]. - **Ingress gateway cannot reach CVP**: survivability TCL scripts on the ingress gateway can reroute calls to another site or dialed number, or play a locally stored.wav file[^49]. - **SIP Service failure after transfer**: the call usually continues, but CVP cannot transfer that call again[^48]. - **Router failure**: in-progress calls that have already reached a VRU or an agent are not affected[^39]. ## Ring-no-answer and requery CVP's RNA timeout is set per pattern in OAMP under System > Dialed Number Pattern[^38]. The RNA timeout must be longer than the Agent Desk Settings RONA timer[^38]. When the RNA timeout expires, CVP sends the router an EventReport of No Answer[^37]. That EventReport triggers a requery if target requery is enabled on the Queue to Skill Group node[^37]. In a requery script, the RequeryStatus variable is tested, and a value greater than zero indicates the call is a requery[^36]. ## Applicability Applies to: Cisco Unified CVP and Cisco Unified Contact Center Enterprise. Deployments: on-premises. Sources checked 2026-10-02. The SendToVRU and Run External Script material comes from a Cisco technote[^25]. The VXML gateway guidance in that technote applies to the IOS VXML gateway[^57]. We infer the 3-point breakdown of VRU-leg failures from that technote, and its applicability to current releases is assumed[^53]. The heartbeat defaults are from the Unified CVP 12.5(1) configuration guide[^21]. Server group configuration and IVR Service failover are documented for Unified CVP 15.0(1)[^46][^26]. Routing, call type and Router trace behaviour are documented for UCCE 15.0(1)[^1][^42]. The dumplog source does not pin a release[^6]. ## What remains uncertain How VRU-leg failures present when Cisco VVB is used instead of an IOS VXML gateway is not covered by the sources below. See also [Cisco VVB](https://warmtransfer.net/knowledge/cisco-vvb). A CVP 15.0(1) table of SIP server group heartbeat defaults is not covered by the sources below. The defaults listed above come from the 12.5(1) guide[^21]. Whether any release uses a Heartbeat Timeout default other than the 500 ms in the 12.5(1) guide is not covered by the sources below. Sources disagree on the default for Number of failed Heartbeats for unreachable status, which the 12.5(1) guide gives as 1[^15]. How that setting relates to a separate heartbeat retry count is not covered by the sources below. Which SIP failure responses make CVP requery the router or invoke survivability is not covered by the sources below. Dialed Number Pattern behaviour for VRU labels beyond Local Static Routes, including any send-to-originator setting, is not covered by the sources below. The meanings of user.microapp.error_code values other than 0 to 3, 5, 16, 31 and 32 are not covered by the sources below. CVP 15.0 Call Server log file names and any changes to the diag page are not covered by the sources below. ## Sources [^1]: UCCE selects a call type for a voice call from the dialed number, caller-entered digits (CED) and calling line ID (CLID). Source: [Configuration Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Routing a Call](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_1501_configuration-guide-for-cisco-unified-icm-enterprise-release/ucce_m_1501_routing-a-call.html), Determine Call Type. Checked 2026-10-02. [^2]: CVP Call Server logs are in C:\Cisco\CVP\logs by default; collect the file covering the time of the failure. Source: [Set Traces and Collect Logs in CCE](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-contact-center-enterprise-1251/218125-set-traces-and-collect-logs-in-cce.html), CVP CallServer section. Checked 2026-10-02. [^3]: To get SIP message detail, set com.dynamicsoft.DsLibs.DsUALibs to DEBUG on the CVP Call Server diag page (port 8000, /cvp/diag), then restore the level after reproducing. Source: [Set Traces and Collect Logs in CCE](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-contact-center-enterprise-1251/218125-set-traces-and-collect-logs-in-cce.html), CVP CallServer section - SIP traces. Checked 2026-10-02. [^4]: For VRU-leg failures Cisco lists the IOS gateway debugs: debug voip ccapi inout, debug ccsip message, debug voip application vxml, debug voip application tcl commands and debug http msg. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Debug commands for troubleshooting - IOS gateway. Checked 2026-10-02. [^5]: When no call type matches, UCCE uses the routing client's default call type, and if none is defined, the general default call type. Source: [Configuration Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Routing a Call](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_1501_configuration-guide-for-cisco-unified-icm-enterprise-release/ucce_m_1501_routing-a-call.html), Determine Call Type. Checked 2026-10-02. [^6]: Given only a process prefix such as rtr, dumplog dumps the current day's log for that process unless dates or times are specified. Source: [Understand how to Use the Dumplog Utility](https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-intelligent-contact-management-enterprise/20406-1.html), Command-line options. Checked 2026-10-02. [^7]: dumplog's /m switch keeps only lines matching a string, /x excludes a string, /ms adds milliseconds, and /last or /prev select the most recent or previous log file. Source: [Understand how to Use the Dumplog Utility](https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-intelligent-contact-management-enterprise/20406-1.html), Command-line options. Checked 2026-10-02. [^8]: dumplog limits output by time with /bd and /ed (dates, mm/dd/yyyy), /bt and /et (times, hh:mm:ss) or /hr (hours back), and writes to a file with /of. Source: [Understand how to Use the Dumplog Utility](https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-intelligent-contact-management-enterprise/20406-1.html), Command-line options. Checked 2026-10-02. [^9]: CVP reports micro-application problems in the user.microapp.error_code ECC variable, usually set when control leaves the X (failure) branch; Cisco advises testing it after every X branch. Source: [Feature Guide - Writing Scripts for Cisco Unified Customer Voice Portal, Release 12.5(1) - Writing Scripts for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/feature/guide/ccvp_b_1251-feature-guide-cisco-unifiedcvp/ccvp_b_1251-feature-guide-cisco-unifiedcvp_chapter_01.html), Unified CVP Script Error Checking. Checked 2026-10-02. [^10]: A CVP log message that the B2BUA is not configured with a route for the label-plus-correlation-ID number means CVP has neither a static route nor a proxy route that matches the VRU label toward the VXML gateway. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issue 2: CVP cannot route VRU label. Checked 2026-10-02. [^11]: The router trace 'Customer (n) has no valid network vru defined - using default' indicates the customer instance is not associated with a network VRU; the fix is to associate it with a valid network VRU. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issue 1: ICM fails to find VRU label - no network VRU on customer. Checked 2026-10-02. [^12]: The router trace 'Customer not found for dialed number ... using default' indicates the dialed number has no customer instance assigned; Cisco's resolution is to define a customer instance for every dialed number rather than rely on the default. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issue 1: ICM fails to find VRU label - no customer defined. Checked 2026-10-02. [^13]: The router trace 'No label configured on network VRU ... for routing client ...' means the Type 10 network VRU lacks a label for that routing client; add a VRU label for each routing client. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issue 1: ICM fails to find VRU label - missing VRU label for routing client. Checked 2026-10-02. [^14]: The router trace 'No NetworkVRU configured for peripheral for VRU capable call on dialed number' means the CVP PG peripheral has no Type 10 network VRU assigned. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issue 1: ICM fails to find VRU label - peripheral gateway missing network VRU. Checked 2026-10-02. [^15]: In the CVP 12.5(1) configuration guide, Number of failed Heartbeats for unreachable status defaults to 1, range 1 through 5 (disputed). Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - System Configuration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010000.html), Heartbeat Properties Settings table - Number of failed Heartbeats for unreachable status. Checked 2026-10-02. [^16]: In the CVP 12.5(1) configuration guide, both Up and Down Endpoint Heartbeat Interval default to 5000 ms with a range of 5000 through 3600000 ms. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - System Configuration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010000.html), Heartbeat Properties Settings table - Up and Down Endpoint Heartbeat Interval (ms). Checked 2026-10-02. [^17]: Heartbeat state changes appear in CVP logs as UnreachableDestinationTable add/remove entries and endpointUnreachableClear events. Source: [Configure and Troubleshoot CVP SIP Heartbeats](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-customer-voice-portal-1251/218122-configure-and-troubleshoot-cvp-sip-heart.html), Troubleshoot section - log samples. Checked 2026-10-02. [^18]: CVP's default Overloaded Response Codes for server group heartbeats are 503, 480 and 600. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - System Configuration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010000.html), Heartbeat Properties Settings table - Overloaded Response Codes. Checked 2026-10-02. [^19]: CVP 12.5(1) heartbeat defaults are local listen port 5067, SIP method OPTIONS (or PING) and transport UDP (or TCP). Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - System Configuration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010000.html), Heartbeat Properties Settings table - Heartbeat Local Listen Port, Heartbeat SIP Method, Heartbeat Transport Type. Checked 2026-10-02. [^20]: Technote 218122 states a default of 3 attempts before a CVP heartbeat destination is marked down (disputed). Source: [Configure and Troubleshoot CVP SIP Heartbeats](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-customer-voice-portal-1251/218122-configure-and-troubleshoot-cvp-sip-heart.html), Configure section - retries. Checked 2026-10-02. [^21]: In the CVP 12.5(1) configuration guide, Heartbeat Timeout defaults to 500 ms with a range of 100 through 3000 ms. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - System Configuration](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010000.html), Heartbeat Properties Settings table - Heartbeat Timeout (ms). Checked 2026-10-02. [^22]: CVP keeps failed destinations in an unreachable destination table; the DsUnreachableDestinationTableTimer default is 180 seconds. Source: [Configure and Troubleshoot CVP SIP Heartbeats](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-customer-voice-portal-1251/218122-configure-and-troubleshoot-cvp-sip-heart.html), Configure section - unreachable destination timer. Checked 2026-10-02. [^23]: CVP SIP server group heartbeats use the SIP OPTIONS method as a ping to learn endpoint status without placing a call. Source: [Configure and Troubleshoot CVP SIP Heartbeats](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-customer-voice-portal-1251/218122-configure-and-troubleshoot-cvp-sip-heart.html), Background on SIP OPTIONS heartbeats. Checked 2026-10-02. [^24]: UCCE process trace logs are stored under [Drive]:\icm\\\logfiles as .ems files. Source: [Serviceability Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Contact Center Trace Levels](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_serviceability-guide-for-cisco-unified-icm-contact-center-enterprise-release-15-0/contact_center_trace_levels.html), Log locations. Checked 2026-10-02. [^25]: For SendToVRU failures Cisco's technote enables router tracing for Route Request, Script Selects, Network VRU Tracing and Call Queuing, and CVP Debug41. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Debug commands for troubleshooting - ICM and CVP. Checked 2026-10-02. [^26]: In CVP 15.0(1), if the IVR Service fails, calls in progress are default-routed to an alternate location on the originating gateway. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 15.0(1) - Configure High Availability for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/15-0-1/configuration/guide/ccvp_b_1501-configuration-guide-for-cisco-customer-voice-portal-release/configure_high_availability_for_unified_cvp.html), IVR Service high availability / survivability. Checked 2026-10-02. [^27]: The comprehensive model needs a Type 10 network VRU with one label per Unified CVP Call Server or NIC routing client. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - Unified CVP Call Flow Models](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010.html), Set Up Comprehensive Call Flow Model Using SIP for ICME and ICMH. Checked 2026-10-02. [^28]: CVP routes a returned label either through Local Static Routes in the Dialed Number Pattern configuration or through a SIP proxy server with static routes for the pattern. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - Unified CVP Call Flow Models](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010.html), Comprehensive call flow - routing label resolution. Checked 2026-10-02. [^29]: For the comprehensive model, CVP's Maximum Length of DNIS is set to the length of the network routing number; with a gateway pattern of 1800 followed by six digits, it is 10. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 12.5(1) - Unified CVP Call Flow Models](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/configuration/guide/ccvp_b_configuration-guide-12-5-1/ccvp_b_configuration-guide-12-5-1_chapter_010.html), Set Up Comprehensive Call Flow Model Using SIP for ICME and ICMH. Checked 2026-10-02. [^30]: user.microapp.error_code values 0 to 3 mean no error, caller hangup, network error and system error. Source: [Feature Guide - Writing Scripts for Cisco Unified Customer Voice Portal, Release 12.5(1) - Writing Scripts for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/feature/guide/ccvp_b_1251-feature-guide-cisco-unifiedcvp/ccvp_b_1251-feature-guide-cisco-unifiedcvp_chapter_01.html), Unified CVP Script Error Checking - error code table. Checked 2026-10-02. [^31]: user.microapp.error_code 16 means the caller reached the maximum number of invalid tries. Source: [Feature Guide - Writing Scripts for Cisco Unified Customer Voice Portal, Release 12.5(1) - Writing Scripts for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/feature/guide/ccvp_b_1251-feature-guide-cisco-unifiedcvp/ccvp_b_1251-feature-guide-cisco-unifiedcvp_chapter_01.html), Unified CVP Script Error Checking - error code table. Checked 2026-10-02. [^32]: user.microapp.error_code 31 means ASR error and 32 means TTS error. Source: [Feature Guide - Writing Scripts for Cisco Unified Customer Voice Portal, Release 12.5(1) - Writing Scripts for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/feature/guide/ccvp_b_1251-feature-guide-cisco-unifiedcvp/ccvp_b_1251-feature-guide-cisco-unifiedcvp_chapter_01.html), Unified CVP Script Error Checking - error code table. Checked 2026-10-02. [^33]: user.microapp.error_code 5 means unknown micro-application. Source: [Feature Guide - Writing Scripts for Cisco Unified Customer Voice Portal, Release 12.5(1) - Writing Scripts for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp_12_5/feature/guide/ccvp_b_1251-feature-guide-cisco-unifiedcvp/ccvp_b_1251-feature-guide-cisco-unifiedcvp_chapter_01.html), Unified CVP Script Error Checking - error code table. Checked 2026-10-02. [^34]: If no default label is defined for the dialed number, UCCE returns an error to the routing client instead of a label. Source: [Configuration Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Routing a Call](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_1501_configuration-guide-for-cisco-unified-icm-enterprise-release/ucce_m_1501_routing-a-call.html), Default Label. Checked 2026-10-02. [^35]: If the routing client's timeout limit is reached before any on-time routing responses arrive, the NIC tells the routing client to stop sending routing requests. Source: [Configuration Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Routing a Call](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_1501_configuration-guide-for-cisco-unified-icm-enterprise-release/ucce_m_1501_routing-a-call.html), Timeout Limit. Checked 2026-10-02. [^36]: In a requery script the RequeryStatus variable is tested; a value greater than zero indicates the call is a requery. Source: [Configure and Troubleshoot RONA with CCE CVP](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-contact-center-enterprise-1262/220673-configure-and-troubleshoot-rona-with-cce.html), Router requery section - RequeryStatus. Checked 2026-10-02. [^37]: When CVP's RNA timeout expires, CVP sends the router an EventReport of No Answer, which triggers a requery if target requery is enabled on the Queue to Skill Group node. Source: [Configure and Troubleshoot RONA with CCE CVP](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-contact-center-enterprise-1262/220673-configure-and-troubleshoot-rona-with-cce.html), Router requery section. Checked 2026-10-02. [^38]: CVP's RNA timeout is set per pattern in OAMP under System > Dialed Number Pattern and must be longer than the Agent Desk Settings RONA timer. Source: [Configure and Troubleshoot RONA with CCE CVP](https://www.cisco.com/c/en/us/support/docs/contact-center/unified-contact-center-enterprise-1262/220673-configure-and-troubleshoot-rona-with-cce.html), Configure - CVP RNA timeout. Checked 2026-10-02. [^39]: A UCCE Router failure does not affect in-progress calls that have already reached a VRU or an agent. Source: [Solution Design Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - High Availability and Network Design](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/design/guide/ucce_b_ucce_soldg-for-unified-cce-1501/rcct_m_high-availability-and-network-design_15_0.html), Response to Private Network Failures. Checked 2026-10-02. [^40]: The router process must be running before router tracing can be set or router traces retrieved, whatever tool is used. Source: [Serviceability Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Contact Center Trace Levels](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_serviceability-guide-for-cisco-unified-icm-contact-center-enterprise-release-15-0/contact_center_trace_levels.html), Router section - note. Checked 2026-10-02. [^41]: Router tracing above default captures Route Requests, Network VRU, Trans Route, VRU Bank, CIC Request, Script Select, Call Queuing, Agent changes and Call Type Real Time. Source: [Serviceability Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Contact Center Trace Levels](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_serviceability-guide-for-cisco-unified-icm-contact-center-enterprise-release-15-0/contact_center_trace_levels.html), Router section. Checked 2026-10-02. [^42]: In UCCE 15.0(1) Router trace levels are 0x00 (default/error), 0x0F (warning), 0xFF (informational) and 0xFFF (debug). Source: [Serviceability Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Contact Center Trace Levels](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_serviceability-guide-for-cisco-unified-icm-contact-center-enterprise-release-15-0/contact_center_trace_levels.html), Router trace levels table. Checked 2026-10-02. [^43]: Router tracing can be set with RTRTRACE (settings take effect immediately), RTTEST or the System CLI. Source: [Serviceability Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Contact Center Trace Levels](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_serviceability-guide-for-cisco-unified-icm-contact-center-enterprise-release-15-0/contact_center_trace_levels.html), Router section - tools. Checked 2026-10-02. [^44]: When the routing script cannot find a destination, UCCE uses the default target (default label) associated with the dialed number. Source: [Configuration Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Routing a Call](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/configuration/guide/ucce_b_1501_configuration-guide-for-cisco-unified-icm-enterprise-release/ucce_m_1501_routing-a-call.html), Run Script; Default Label. Checked 2026-10-02. [^45]: A CVP SIP server group lets the originating endpoint know the destination's status before it sends the INVITE, so failed endpoints are skipped faster. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 15.0(1) - Configure High Availability for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/15-0-1/configuration/guide/ccvp_b_1501-configuration-guide-for-cisco-customer-voice-portal-release/configure_high_availability_for_unified_cvp.html), Server Groups section. Checked 2026-10-02. [^46]: CVP server groups are not added automatically; they must be configured explicitly, and at least one Call Server must exist before the settings can be saved. Source: [Configuration Guide for Cisco Unified Customer Voice Portal, Release 15.0(1) - Configure High Availability for Unified CVP](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/15-0-1/configuration/guide/ccvp_b_1501-configuration-guide-for-cisco-customer-voice-portal-release/configure_high_availability_for_unified_cvp.html), Server Groups section - configuration notes. Checked 2026-10-02. [^47]: A server group can send heartbeats only to the endpoints defined in it. Source: [Solution Design Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - High Availability and Network Design](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/design/guide/ucce_b_ucce_soldg-for-unified-cce-1501/rcct_m_high-availability-and-network-design_15_0.html), Server Groups and CVP High Availability. Checked 2026-10-02. [^48]: If the CVP SIP Service fails after the caller has been transferred, the call usually continues, but CVP cannot transfer that call again. Source: [Solution Design Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - High Availability and Network Design](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/design/guide/ucce_b_ucce_soldg-for-unified-cce-1501/rcct_m_high-availability-and-network-design_15_0.html), Call Survivability During Failovers - CVP Call Server. Checked 2026-10-02. [^49]: Survivability TCL scripts on the ingress gateway can reroute calls to another site or dialed number, or play a locally stored .wav file, when the gateway cannot reach CVP. Source: [Solution Design Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - High Availability and Network Design](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/icm_enterprise/icm_enterprise_15_0_1/design/guide/ucce_b_ucce_soldg-for-unified-cce-1501/rcct_m_high-availability-and-network-design_15_0.html), High Availability for Ingress and Egress Gateways. Checked 2026-10-02. [^50]: The CVP SendToVRU and Run External Script troubleshooting note requires a Type 10 network VRU, with a label added for every CVP PG. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Critical configuration requirements (network VRU type). Checked 2026-10-02. [^51]: The Call Server log message 'VRU APPLICATION ERROR: Assigning the tag 7 to the non-existing ECC variable' means the ECC variable is missing in ICM/NAM or defined with different lengths; the fix is an identical ECC definition. Source: [Troubleshoot CVP Call Server Problems](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal/212350-troubleshoot-cvp-call-server-problems.html), Problem Summary 6. Checked 2026-10-02. [^52]: For SendToVRU to work, the VRU label length must match the Maximum Length of DNIS configured on CVP. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Critical configuration requirements (label configuration). Checked 2026-10-02. [^53]: A failed VRU leg can break at three separable points: the router finding a VRU label, CVP routing the label plus correlation ID, and the VXML gateway matching a dial-peer with the right application; each leaves evidence in a different log (inferred). Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issues 1, 2 and 3 taken together. Checked 2026-10-02. [^54]: The VXML Server application error logger records Java exceptions (optionally with stack traces), application timeouts and errors from other loggers in that application. Source: [User Guide for Cisco Unified CVP VXML Server and Cisco Unified Call Studio Release 12.6(2) - VXML Server Logging](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/12-6-2/user/guide/ccvp_b_1262-user-guide-for-cisco-unified-cvp-vxml-server-and-call-studio/ccvp_b_1251-user-guide-for-cisco-unified-cvp-vxml-server-and-cisco-unified-call-studio-release-1251_chapter_0100.html), Application Loggers - error logger. Checked 2026-10-02. [^55]: Since CVP 8.0(1), VXML Server receives callid (the call GUID), _dnis and _ani by default; they appear in the VXML Server log and callid links Call Server logs to VXML Server logs. Source: [User Guide for Cisco Unified CVP VXML Server and Cisco Unified Call Studio Release 12.6(2) - VXML Server Logging](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/12-6-2/user/guide/ccvp_b_1262-user-guide-for-cisco-unified-cvp-vxml-server-and-call-studio/ccvp_b_1251-user-guide-for-cisco-unified-cvp-vxml-server-and-cisco-unified-call-studio-release-1251_chapter_0100.html), Correlating Unified CVP Call Server Logs with VXML Server Logs. Checked 2026-10-02. [^56]: VXML Server global call and error logs are written daily under %CVP_HOME%\VXMLServer\logs\GlobalCallLogger and GlobalErrorLogger. Source: [User Guide for Cisco Unified CVP VXML Server and Cisco Unified Call Studio Release 12.6(2) - VXML Server Logging](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/12-6-2/user/guide/ccvp_b_1262-user-guide-for-cisco-unified-cvp-vxml-server-and-call-studio/ccvp_b_1251-user-guide-for-cisco-unified-cvp-vxml-server-and-cisco-unified-call-studio-release-1251_chapter_0100.html), Global Loggers - call log and error log. Checked 2026-10-02. [^57]: If the VRU dial-peer has no application bound, the gateway hands the call to the default application; the IOS VXML gateway needs the TCL bootstrap application with the cvphost parameter set and header-passing enabled. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issue 3: VXML gateway fails to invoke VRU script - missing application on dial-peer. Checked 2026-10-02. [^58]: A VRU leg that reaches the VXML gateway but matches a default dial-peer instead of the VRU dial-peer fails to run the VRU script; causes include no VRU dial-peer, a pattern that does not match the DNIS, or a missing signature digit. Source: [CVP "Send to VRU" and "Run Ext Script" Failures](https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-customer-voice-portal-901/116178-technote-cvp-00.html), Issue 3: VXML gateway fails to invoke VRU script - incorrect dial-peer matching. Checked 2026-10-02.