Cisco 300-815 CLACCM study materials
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Cisco 300-815 CLACCM cheat sheet

Cisco 300-815 CLACCM · Keep the key ideas within reach.

Quick reference

Call Control and Dial Planning

  • Dial-peer matching order: exact-match dial-peer first, then longest match on the destination pattern; preference (lower value wins) breaks ties among equal-length matches, then the dial-peer with the lowest tag if preference also ties.

  • Cisco IOS destination patterns: '.' matches any single digit, 'T' matches one or more digits and inserts interdigit timeout, '[1-4]' is a digit range, and '$' is an end-of-string anchor; '^' anchors the start.

  • Translation rules operate in two steps: the match pattern selects the rule, and the replace pattern (with backslash-referenced wildcards such as \1) rewrites the number; unmatched calls are dropped when a translation-profile has no pass-through.

  • For SIP trunking, dial-peer voice sip-ua with 'session protocol sipv2' and 'session target ipv4:' sends calls to a peer; 'codec' and 'dtmf-relay' are negotiated per dial-peer.

  • Call routing uses the called number unless 'incoming called-number' or 'answer-address' or 'destination-pattern' with 'incoming called-number' is configured; voice translation profiles can be applied inbound or outbound on a POTS or VoIP dial-peer.

  • Digit manipulation order in CUCM: translation patterns, route patterns, then route group/route list selection; partitions and calling search spaces determine which patterns a calling device can reach.

  • Route lists are ordered; the first route group with an available member is chosen, and if all members of a group are busy, the list rolls to the next group unless 'route list' is configured with a stop-on-busy option.

  • Preemption and CAC: locations and regions govern bandwidth per call; a call that exceeds the location bandwidth is either rejected or, with a configured AAR group, rerouted through the PSTN.

Quick reference

Call Control and Mobility Services

  • Extension Mobility: a user logs in to a phone, which downloads the device profile; the physical phone MAC is mapped to a device profile, and EM uses the Cisco Extension Mobility service on CUCM.

  • Device Mobility: a phone in a remote site uses the device mobility group to select the correct location, region, and CSS based on the IP subnet of the phone and the device mobility info.

  • Mobile Connect (SNR): an incoming call to the desk phone rings the remote destination (mobile) and the desk phone; answer on either leg, and the remote destination can be configured with a delay.

  • Mobile Voice Access: an IVR allows a user to place calls and change Mobile Connect settings from a remote phone; it uses the application dial rules and a CTI route point.

  • Hunt groups: broadcast, longest idle, circular, and top-down algorithms distribute calls; hunt pilots have a CSS and a queue/agent configuration.

  • Call Park: a call is parked on a park slot number and retrieved by dialing the slot; the park range is configured in the CUCM cluster-wide call park settings.

  • Intercom: a one-way call between two users; the called party hears beep and the call is auto-answered; intercom uses a dedicated directory number and 'intercom' as the line type.

  • Presence and BLF: BLF uses a phone button template and a presence group; the presence group controls which users can see each other's status.

  • Call forwarding types: CFNA, CFB, CFU; each uses a CSS that determines the forwarding destination reachable by the user.

Quick reference

Call Control and Mobility Troubleshooting

  • Use 'show dial-peer voice summary' to verify the matched dial-peer; the 'in' and 'out' columns show the inbound and outbound peer for a test call.

  • Use 'debug voice ccapi inout' to trace call setup, dial-peer matching, translation, and disconnect cause codes; 'debug isdn q931' shows the ISDN cause value.

  • Common disconnect causes: 16 normal call clearing, 21 call rejected, 34 no circuit/channel available, 38 network out of order, 47 resource unavailable.

  • CUCM traces: use the Real-Time Monitoring Tool (RTMT) to collect traces; the SDL and CCM traces show the call flow, and the 'Call Control' trace shows digit analysis.

  • Digit analysis: in CUCM, a route pattern with 'Urgent Priority' unchecked is not used if a longer match exists; check the 'Called Party Number' transformation and the CSS/partition.

  • For SIP, check the 'Reason' header and the SIP response code; 404 not found means no route pattern matched, 503 service unavailable means no gateway available.

  • Check 'show sip-ua status' and 'show sip-ua calls' on the gateway; verify the SIP trunk registration and the 'session target' on the dial-peer.

  • Media issues: verify the codec, the MTP/transcoder resource, and the region bandwidth; a 'no media' symptom often means a codec mismatch or a missing MTP.

  • For EM login failures, check the device profile, the EM service, and the user's associated device profile; the phone must have the EM service subscribed.

Quick reference

Mobility and Remote Access

  • Cisco Jabber: uses the UDS or SOAP service to discover the CUCM; the service profile defines the voicemail, directory, and IM&P servers.

  • Mobile and Remote Access (MRA) uses Expressway-C and Expressway-E; the internal Expressway-C connects to CUCM, and the external Expressway-E is in the DMZ.

  • MRA requires a traversal zone between Expressway-C and Expressway-E, and a SIP/HTTPS zone between Expressway-C and CUCM.

  • VPN access: a remote phone can use a VPN client or the AnyConnect VPN; the phone uses the VPN to reach CUCM through the ASA.

  • Cisco Unified Mobility: the remote destination is configured on the CUCM, and the Mobile Connect feature uses the remote destination profile.

  • Certificate requirements for MRA: the Expressway-E certificate must be trusted by the client, and the certificate must include the SIP domain and the Expressway-E FQDN in the SAN.

  • The Expressway-E uses a public certificate; the Expressway-C uses an internal certificate signed by the CUCM certificate authority.

  • Remote phone firmware: the phone downloads firmware from the TFTP server; for MRA, the phone uses the Expressway-E as the proxy for TFTP.

Quick reference

Security and Policy Enforcement

  • CUCM partitions and CSS enforce calling privileges: a CSS is a list of partitions, and a device can only dial numbers in partitions in its CSS.

  • Time-of-day routing uses a time schedule and a time period; a route pattern can be assigned a time schedule to allow calls only during certain hours.

  • Toll fraud prevention: use a CSS on the gateway that blocks international patterns, and use 'forbidden' patterns in a partition not in the CSS.

  • SIP security: TLS for signaling and SRTP for media; configure a secure SIP trunk with 'srtp' and a certificate trust.

  • Phone security: a secure phone uses a certificate (MIC) and an encrypted TFTP configuration; the phone must be in a secure cluster.

  • The 'SIP trunk security profile' defines the TLS port, the digest authentication, and the incoming/outgoing transport.

  • Application dial rules and directory lookup dial rules control how numbers are dialed from the directory; they are applied before the CSS.

  • Cisco UCM 'Enterprise Parameters' include the 'Cluster Security Mode' (mixed or secure) and the 'Certificate Expiry' monitoring.

  • For 802.1X, the phone uses EAP-TLS or EAP-FAST; the switch port must be configured for multi-domain authentication.