# CUBE troubleshooting commands Canonical: https://warmtransfer.net/knowledge/cube-troubleshooting-toolkit Last verified: 2026-09-25 Cisco Unified Border Element (CUBE) provides logging commands, live active call displays, signaling debugs, and integrated VoIP Trace facilities to isolate call failures and errors[^22][^42]. Cisco warns that debug commands generate significant output and can disrupt router operation under heavy load, recommending verification with show commands before running debugs[^19][^20]. ## Logging buffer and router protection Cisco's CUBE debug-collection baseline configures `logging buffered 10000000`, creating a 10 MB local log buffer, and notes that this size can be adjusted[^22]. Cisco states that most CUBE debug scenarios require at least a 10 MB log buffer to ensure enough output is captured before older entries are overwritten[^3]. The baseline disables console and monitor logging through `no logging console` and `no logging monitor` to prevent debug output from degrading router performance[^25]. Cisco explains that Cisco IOS prioritizes console debug output over other router functions, meaning heavy console debugging can cause the router to hang[^14]. Cisco also warns that syslog servers tend to drop or skip lines of debug output when congested, even though documentation provides a `logging host` configuration[^34]. The recommended logging baseline includes the following system settings: * Timestamp formatting: Sets `service timestamps debug` and `service timestamps log` to `datetime msec localtime show-timezone year` and enables `service sequence-numbers`[^36]. * Queue and rate control: Configures `logging queue-limit 10000` and `logging rate-limit 10000`[^28]. * Call disconnection analysis: Enables `voice iec syslog` to emit Voice Internal Error Code (IEC) messages that identify why a call disconnected[^39]. ## Show commands and active call inspection Before turning on debugs, Cisco specifies running `show process cpu sorted | exclude 0.00` to evaluate the 5-second, 1-minute, and 5-minute CPU utilization values as well as top processes[^16]. To examine live calls, `show sip-ua calls [brief]` executes in privileged EXEC mode to display active SIP user agent client (UAC) and user agent server (UAS) call information[^33]. The fields displayed by `show sip-ua calls` include the SIP call ID, call state and substate, calling and called numbers, signaling source address, SIP request and response destination address and port, media source and destination IP and port, and the negotiated codec[^31]. The active voice call table can also be inspected with `show call active voice`, which runs in user EXEC and privileged EXEC modes[^6]. A shortened view is available via the `brief` keyword[^6]. Output can be restricted using keywords such as `brief`, `called-number`, `calling-number`, `compact`, `id`, `session-id`, and `stats`[^5]. ## Signaling debugs and conditional filtering Cisco's baseline SIP debug set consists of `debug ccsip messages`, `debug ccsip error`, `debug ccsip non-call`, and `debug voip ccapi inout`[^2]. Cisco describes `debug ccsip messages` as enabling all SIP SPI message tracing[^11]. Additional available `debug ccsip` keywords are `all` (for all SIP-related debugging), `calls`, `error`, `events`, `info`, `media`, `messages`, `preauth`, `states`, and `transport`[^9]. Cisco classifies `debug ccsip all` and `debug ccsip verbose` as advanced SIP debugs and instructs operators to watch CPU load closely while advanced debugs run[^1]. In contrast, Cisco notes that `debug voip ccapi inout` usually has minimal CPU impact and recommends running it alongside any signaling debugs[^8]. For digital PRI and BRI flows traversing the same gateway, the reference lists `debug isdn q931` and `debug isdn q921`[^35]. Conditional debugging narrows debug generation to specific traffic flows using `debug condition match-list {exact-match | partial-match}`, where the match-list number ranges from 1 to 16[^18]. Before running this command, the match list must be defined using `call filter match-list`[^24]. When `exact-match` is selected, all debug output is filtered out until every condition in the list is met[^21]. With `partial-match`, no debug output is filtered out until a single condition fails to match[^26]. The configuration and operational state of the filter are viewed using `show call filter match-list`[^29]. In the field, match lists are built from incoming and outgoing calling and called numbers, signaling and media IP addresses, and dial-peer tags, and are typically activated with `exact-match`[^23]. In the field, operators confirm that conditional filtering is functioning by verifying that `show debug` labels the debug with `(filter is ON)`[^30]. ### Debug capture workflow Cisco's standard debug capture procedure follows these execution steps: * Clear existing buffer entries using `clear log` before reproducing the issue[^12]. * Collect the buffered content using `terminal length 0` followed by `show log`, or export the content off-box using `show log | redirect` to an FTP URL[^13]. * Disable debugging across the platform by running `undebug all` once output has been collected[^38]. ## VoIP Trace VoIP Trace on CUBE is enabled by default and records SIP signaling along with call events without requiring debug commands to be turned on[^42]. It records SIP messages for SIP-trunk-to-SIP-trunk calls, CCSIP messages, events, and APIs, SIP errors, call-control flows handled by CUBE, and finite state machine (FSM) states and events[^40]. VoIP Trace maintains all trace records in system memory, allocating up to 10% of available platform memory by default[^46][^44]. A custom memory cap between 10 and 1000 MB can be set under `voice service voip` > `trace` using the `memory-limit` command[^46]. When this limit is reached, older traces are overwritten[^47]. Lowering the `memory-limit` resets existing trace data[^45]. Furthermore, executing `shutdown` in VoIP Trace configuration halts active tracing and deletes all retained traces[^53]. When calls encounter IEC errors, VoIP Trace writes their data directly to the logging buffer in addition to memory storage[^44]. Trace collection for error calls is capped at a rate of up to 5 traces per second[^43]. ### VoIP Trace operational rules and inspection VoIP Trace cannot trace calls that have only a single SIP leg, and cannot trace incoming calls once active calls have exhausted the allocated memory limit[^51]. Its trace records cover only the SIP leg of a call, though forked legs are also captured when media forking is active[^54]. | Command / Keyword | Function | | --- | --- | | `show voip trace` syntax | Accepts `call-id`, `session-id`, `sip-call-id`, `correlator`, `all`, `cover-buffers`, `statistics`, and `detail`[^52]. | | Cover buffers | Starting with Cisco IOS XE Dublin 17.12.1a, cover buffers include the call's cause code[^15]. | | Tenant filtering | Introduced at Cisco IOS XE Cupertino 17.8.1a[^56]. | In the field, engineers search `show voip trace cover-buffers` for specific calls using the calling number, called number, or call-id, and then display the target trace with `show voip trace call-id` rather than displaying the entire buffer[^41]. ## See also * [Cisco Unified Border Element configuration and licensing](https://warmtransfer.net/knowledge/cube-configuration) * [CUBE dial-peer matching and voice class URI and translation profiles](https://warmtransfer.net/knowledge/cube-dial-peers) * [CUBE high availability](https://warmtransfer.net/knowledge/cube-high-availability) * [Unified CM SIP trunk to CUBE configuration](https://warmtransfer.net/knowledge/cucm-config-sip-trunk-to-cube) * [Troubleshooting a Webex Calling Local Gateway](https://warmtransfer.net/knowledge/webex-local-gateway-troubleshooting) ## Applicability Applies to: Cisco CUBE, Cisco IOS XE TDM gateway, Cisco IOS voice gateway, Cisco IOS routers, and Cisco IOS SIP gateway. Deployments: on-premises. Sources checked 2026-09-25. The CUBE configuration guide feature table lists VoIP Trace as introduced in Cisco IOS XE Amsterdam 17.3.2[^48], while tech note 215208 states VoIP Trace arrived with Cisco IOS XE 17.4.1 and 17.3.2[^50]. Tenant-based filtering for VoIP Trace is listed for Cisco IOS XE Cupertino 17.8.1a[^56]. Cover buffer cause code reporting was introduced in Cisco IOS XE Dublin 17.12.1a[^15]. Conditional debugging with `debug condition match-list` was introduced in Cisco IOS 12.3(4)T[^18]. ## What remains uncertain The quantified CPU cost of `debug ccsip messages` per call rate or platform is not covered by the sources below. SIP methods excluded from VoIP Trace, including REGISTER, OPTIONS, SUBSCRIBE, NOTIFY, and INFO, are not covered by the sources below. Reading dial-peer matching and disconnect causes inside `debug voip ccapi inout` output is not covered by the sources below. Embedded packet capture via `monitor capture` on CUBE for RTP and SIP packets is not covered by the sources below. Official command reference entries for `debug ccsip messages`, `debug ccsip non-call`, and `debug ccsip verbose` are not covered by the sources below. Using Collaboration Solutions Analyzer for CUBE log analysis is not covered by the sources below. The CLI syntax for tenant-based filtering in VoIP Trace under Cisco IOS XE 17.8.1a is not covered by the sources below. Whether VoIP Trace covers H.323 or TDM call legs is not covered by the sources below. ## Sources [^1]: Cisco lists 'debug ccsip all' and 'debug ccsip verbose' as advanced SIP debugs and says to watch the CPU closely while advanced debugs are running. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Advanced SIP Debugs list and accompanying CPU caution. Checked 2026-09-25. [^2]: Cisco's basic SIP debug set for CUBE is 'debug ccsip messages', 'debug ccsip error', 'debug ccsip non-call' and 'debug voip ccapi inout'. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Basic SIP Debugs list. Checked 2026-09-25. [^3]: Cisco says most CUBE debug scenarios need a log buffer of at least 10 MB so that enough output is collected before it is overwritten. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Logging configuration explanation, logging buffered bullet. Checked 2026-09-25. [^4]: 'show call active voice brief' output starts with a legend of the form ' A/O FAX T Codec type Peer IP R: VRF'. Per-leg lines include duration, tx/rx packet counts, playout, lost/early/late packet counts, delay and codec. Source: [Cisco IOS Voice Command Reference - S commands - show aal2 profile through show call filter match-list](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s3.html), show call active voice entry: brief output field descriptions. Checked 2026-09-25. [^5]: 'show call active voice' can be narrowed with keywords including brief, called-number, calling-number, id, compact, session-id and stats. Source: [Cisco IOS Voice Command Reference - S commands - show aal2 profile through show call filter match-list](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s3.html), show call active voice entry: Syntax. Checked 2026-09-25. [^6]: 'show call active voice' runs in user EXEC and privileged EXEC mode and shows the contents of the active voice call table. The 'brief' keyword gives a shortened view. Source: [Cisco IOS Voice Command Reference - S commands - show aal2 profile through show call filter match-list](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s3.html), show call active voice entry: Command Modes and Usage Guidelines. Checked 2026-09-25. [^7]: When a call ends, its record moves to the call history table, which 'show call history voice' displays. The table holds 0 to 500 entries (default 50), and entries age out after a configurable interval (default 15 minutes). Source: [Cisco IOS Voice Command Reference - S commands - show call history fax through show debug condition](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s4.html), show call history voice entry: Usage Guidelines. Checked 2026-09-25. [^8]: Cisco says 'debug voip ccapi inout' usually has minimal CPU impact and recommends enabling it alongside any signaling debugs. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Internal call control debug section. Checked 2026-09-25. [^9]: The SIP guide lists these 'debug ccsip' keywords: all (all SIP-related debugging), calls, error, events, info, media, messages, preauth, states and transport. Source: [SIP Configuration Guide, Cisco IOS Release 15M&T - Verifying and Troubleshooting SIP Features](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/sip/configuration/15-mt/sip-config-15-mt-book/voi-sip-verify.html), Using debug Commands, debug ccsip keyword list. Checked 2026-09-25. [^10]: Cisco puts no number on the CPU cost of 'debug ccsip messages'. Its guidance is qualitative and scaled by current CPU: it treats ccsip messages as a basic debug, allowed at about 50% CPU, while all debugs must stop above about 80%. The practical cost therefore depends on call rate and has to be judged from 'show process cpu' on the box (inferred). Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), CPU guidance and Basic SIP Debugs list. Checked 2026-09-25. [^11]: Cisco's SIP guide describes 'debug ccsip messages' as enabling all SIP SPI message tracing. Source: [SIP Configuration Guide, Cisco IOS Release 15M&T - Verifying and Troubleshooting SIP Features](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/sip/configuration/15-mt/sip-config-15-mt-book/voi-sip-verify.html), Using debug Commands, debug ccsip keyword list. Checked 2026-09-25. [^12]: Cisco's collection procedure runs 'clear log' to empty the buffer before the issue is reproduced. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Output collection procedure. Checked 2026-09-25. [^13]: To collect output, Cisco uses 'terminal length 0' followed by 'show log', or sends the output off the box with 'show log | redirect' to an FTP URL. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Output collection procedure. Checked 2026-09-25. [^14]: IOS gives debug output to the console priority over other router functions, so heavy console debugging can hang the router. Source: [Understand Important Information on Debug Commands](https://www.cisco.com/c/en/us/support/docs/dial-access/integrated-services-digital-networks-isdn-channel-associated-signaling-cas/10374-debug.html), Background / debug output destinations. Checked 2026-09-25. [^15]: Starting with Cisco IOS XE Dublin 17.12.1a, VoIP Trace cover buffers show the call's cause code (Cover Buffer Enhancements for VoIP Trace). Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Feature Information for VoIP Trace table, Cover Buffer Enhancements row. Checked 2026-09-25. [^16]: Before enabling debugs, Cisco says to run 'show process cpu sorted | exclude 0.00' to check the 5-second, 1-minute and 5-minute CPU values and the top processes. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), CPU check step before debug enablement. Checked 2026-09-25. [^17]: Cisco's CPU guidance for CUBE debugs: at about 30% CPU or less, basic through advanced debugs can be enabled; at about 50%, use basic debugs only and keep monitoring; above 80%, stop debugs immediately and engage support. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), CPU guidance preceding the debug lists. Checked 2026-09-25. [^18]: The syntax is 'debug condition match-list number {exact-match | partial-match}'. The match-list number ranges from 1 to 16, and the command was introduced in IOS 12.3(4)T. Source: [Cisco IOS Debug Command Reference - Commands A through D - debug clns esis events through debug dbconn tcp](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/debug/command/a1/db-a1-cr-book/db-c1.html), debug condition match-list entry: Syntax, Syntax Description, Command History. Checked 2026-09-25. [^19]: Cisco warns that enabling debugging can disrupt router operation, especially when the network is under heavy load. Source: [Understand Important Information on Debug Commands](https://www.cisco.com/c/en/us/support/docs/dial-access/integrated-services-digital-networks-isdn-channel-associated-signaling-cas/10374-debug.html), Important information / caution. Checked 2026-09-25. [^20]: Cisco's SIP guide warns that debug commands produce a high volume of output even under moderate traffic, and recommends trying show commands first. Source: [SIP Configuration Guide, Cisco IOS Release 15M&T - Verifying and Troubleshooting SIP Features](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/sip/configuration/15-mt/sip-config-15-mt-book/voi-sip-verify.html), Using debug Commands, introductory caution. Checked 2026-09-25. [^21]: With 'exact-match', all related debug output is filtered until every condition in the match list is explicitly met. Source: [Cisco IOS Debug Command Reference - Commands A through D - debug clns esis events through debug dbconn tcp](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/debug/command/a1/db-a1-cr-book/db-c1.html), debug condition match-list entry: Syntax Description, exact-match. Checked 2026-09-25. [^22]: Cisco's CUBE debug-collection baseline sets 'logging buffered 10000000', a 10 MB local log buffer, and notes that the size can be adjusted. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Recommended logging configuration block (baseline 'configure terminal' listing). Checked 2026-09-25. [^23]: In practice, CUBE call filter match-lists are built from incoming and outgoing calling and called numbers, signaling and media IP addresses, and dial-peer tags, and are typically applied with 'exact-match' (field report). Source: [Filtering Cisco CUBE Debug Messages](https://fatiherikci.com/en/filtering-cisco-cube-debug-messages/), Match conditions and configuration example sections. Checked 2026-09-25. [^24]: 'debug condition match-list' filters voice call debugging against a match list, and the list must first be defined with the 'call filter match-list' command. Source: [Cisco IOS Debug Command Reference - Commands A through D - debug clns esis events through debug dbconn tcp](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/debug/command/a1/db-a1-cr-book/db-c1.html), debug condition match-list entry: Usage Guidelines. Checked 2026-09-25. [^25]: The CUBE debug baseline turns off console and monitor logging ('no logging console', 'no logging monitor') so that debug output does not degrade router performance. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Recommended logging configuration block and its explanation bullets. Checked 2026-09-25. [^26]: With 'partial-match', no related debug output is filtered until a single condition explicitly fails to match. Source: [Cisco IOS Debug Command Reference - Commands A through D - debug clns esis events through debug dbconn tcp](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/debug/command/a1/db-a1-cr-book/db-c1.html), debug condition match-list entry: Syntax Description, partial-match. Checked 2026-09-25. [^27]: For voice-quality troubleshooting, Cisco points to these fields in 'show call active voice': LostPackets, ReceiveDelay, GapFillWithSilence, GapFillWithPrediction, Hi/LoWaterPlayoutDelay, VAD, CoderTypeRate and the ACOM/ERL echo levels. Source: [Using the show call active voice Command to Troubleshoot Voice Quality Issues](https://www.cisco.com/c/en/us/support/docs/voice/voice-quality/40309-show-call-act-voice.html), Voice quality related fields section. Checked 2026-09-25. [^28]: The CUBE debug baseline includes 'logging queue-limit 10000' and 'logging rate-limit 10000'. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Recommended logging configuration block. Checked 2026-09-25. [^29]: 'show call filter match-list' displays the call filter match-list configuration and status used for voice call filtering. Source: [Cisco IOS Voice Command Reference - S commands - show aal2 profile through show call filter match-list](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s3.html), show call filter match-list entry. Checked 2026-09-25. [^30]: Practitioners confirm conditional debugging is active by checking that 'show debug' marks the debug with '(filter is ON)' (field report). Source: [Filtering Cisco CUBE Debug Messages](https://fatiherikci.com/en/filtering-cisco-cube-debug-messages/), Verification commands section. Checked 2026-09-25. [^31]: 'show sip-ua calls' output includes the SIP call ID, call state and substate, calling and called numbers, signaling source address, SIP request and response destination address:port, media source and destination IP:port, and negotiated codec. Source: [Cisco IOS Voice Command Reference - S commands - show sip service through show trunk hdlc](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s8.html), show sip-ua calls entry: field description table. Checked 2026-09-25. [^32]: 'show sip-ua calls' was introduced in IOS 12.2(15)T. Later releases added AEAD cipher-suite display (IOS XE Everest 16.5.1b), local and remote crypto key fields (IOS XE 16.11.1) and WebSocket call fields (IOS XE Bengaluru 17.6.1a). Source: [Cisco IOS Voice Command Reference - S commands - show sip service through show trunk hdlc](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s8.html), show sip-ua calls entry: Command History table. Checked 2026-09-25. [^33]: 'show sip-ua calls [brief]' runs in privileged EXEC mode and shows active SIP user agent client (UAC) and user agent server (UAS) call information. Source: [Cisco IOS Voice Command Reference - S commands - show sip service through show trunk hdlc](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s8.html), show sip-ua calls entry: Syntax, Command Modes, Usage Guidelines. Checked 2026-09-25. [^34]: Cisco warns that syslog servers tend to skip or drop lines of debug output when the server is congested, even though the tech note gives a 'logging host' configuration. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Syslog server logging section. Checked 2026-09-25. [^35]: For digital PRI and BRI call flows on the same gateways, the tech note lists 'debug isdn q931' and 'debug isdn q921'. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Digital (PRI, BRI) Call Flows debug list. Checked 2026-09-25. [^36]: The CUBE debug baseline sets 'service timestamps debug' and 'service timestamps log' to 'datetime msec localtime show-timezone year' and turns on 'service sequence-numbers'. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Recommended logging configuration block. Checked 2026-09-25. [^37]: On IOS XE 17.3.2 or later with VoIP Trace left on, a failed SIP-trunk-to-SIP-trunk call can often be reviewed after the fact with 'show voip trace' without enabling debugs, provided the trace has not been overwritten. Out-of-scope calls, single-leg calls and any SIP methods VoIP Trace does not capture still need the buffered-debug procedure (inferred). Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Overview, Restrictions, and memory behaviour sections. Checked 2026-09-25. [^38]: Cisco turns debugs off with 'undebug all' once output has been collected. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Output collection procedure, final step. Checked 2026-09-25. [^39]: The 'voice iec syslog' command turns on Voice Internal Error Code (IEC) messages, which help identify why a call disconnected. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Recommended logging configuration explanation, voice iec syslog bullet. Checked 2026-09-25. [^40]: VoIP Trace records SIP messages for SIP-trunk-to-SIP-trunk calls, CCSIP messages, events and APIs, SIP errors, call-control flows processed by CUBE, and FSM states and events. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Overview, list of recorded information. Checked 2026-09-25. [^41]: In the field, engineers search 'show voip trace cover-buffers' for the call by calling number, called number or call-id, then run 'show voip trace call-id' instead of dumping every trace (field report). Source: [CUBE VoIP Trace Feature](https://www.lookingpoint.com/blog/cube-voip-trace-feature), Finding calls section. Checked 2026-09-25. [^42]: VoIP Trace on CUBE is enabled by default. It logs SIP signaling and call events without any debug being turned on. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Overview / Prerequisites. Checked 2026-09-25. [^43]: VoIP Trace logs traces for error calls at up to five traces per second. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Overview, error call logging. Checked 2026-09-25. [^44]: VoIP Trace keeps all call trace data in system memory. For calls with IEC errors, the data is also written to the logging buffer. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Overview, data storage. Checked 2026-09-25. [^45]: Lowering the VoIP Trace memory-limit resets the existing VoIP Trace data. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Configure VoIP Trace, memory-limit usage note. Checked 2026-09-25. [^46]: By default VoIP Trace uses up to 10% of available platform memory. The 'memory-limit' command under 'voice service voip' > 'trace' can set a custom value from 10 to 1000 MB instead. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Configure VoIP Trace, memory-limit command. Checked 2026-09-25. [^47]: When VoIP Trace reaches its memory limit, older traces are overwritten. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Overview, memory behaviour. Checked 2026-09-25. [^48]: The CUBE configuration guide's feature table lists VoIP Trace as introduced in Cisco IOS XE Amsterdam 17.3.2. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Feature Information for VoIP Trace table. Checked 2026-09-25. [^49]: The two Cisco documents do not contradict each other on VoIP Trace's first release. The configuration guide lists only the 17.3.2 train, while the tech note also names 17.4.1. The safest reading is that 17.3.2 or later on the 17.3 train, and 17.4.1 or later, include the feature (inferred). Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), VoIP Trace section, opening sentence; compared with cisco-cube-xe-config-voip-trace feature table. Checked 2026-09-25. [^50]: Tech note 215208 says VoIP Trace arrived with Cisco IOS XE 17.4.1 and 17.3.2. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), VoIP Trace section, opening sentence. Checked 2026-09-25. [^51]: VoIP Trace cannot trace incoming calls once active calls have used up the memory limit, and it cannot trace calls that have only a single SIP leg. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Restrictions for VoIP Trace. Checked 2026-09-25. [^52]: The 'show voip trace' command accepts call-id, session-id, sip-call-id, correlator, all, cover-buffers, statistics and detail. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Display VoIP Trace data, show voip trace syntax. Checked 2026-09-25. [^53]: Running 'shutdown' in VoIP Trace configuration stops tracing for active calls and deletes all existing traces, so disabling VoIP Trace discards whatever it has captured. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Configure VoIP Trace, shutdown command. Checked 2026-09-25. [^54]: The 'show voip trace' output covers only the SIP leg of a call. For media forking, it also shows the forked legs. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Display VoIP Trace data, usage notes. Checked 2026-09-25. [^55]: One practitioner reports that VoIP Trace does not log REGISTER, OPTIONS, SUBSCRIBE/NOTIFY or INFO messages, so those still need debugs (field report). Source: [CUBE VoIP Trace Feature](https://www.lookingpoint.com/blog/cube-voip-trace-feature), Limitations paragraph. Checked 2026-09-25. [^56]: The VoIP Trace feature table lists Tenant-based Filtering for VoIP Trace at Cisco IOS XE Cupertino 17.8.1a. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: VoIP Trace](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voip-trace-for-cube.html), Feature Information for VoIP Trace table, Tenant-based Filtering row. Checked 2026-09-25.