CCIE Collaboration cheat sheet

Cisco Unified CM cluster sizing: maximum 20,000 users per cluster for a single-cluster design (up to 40,000 with a second cluster in an Intercluster Lookup Service-enabled multi-cluster deployment); OVA templates set CUCM subscriber capacity per node (7,500, 10,000, or 20,000 users).

Cluster node roles: publisher holds the master database and replicates to subscribers; call processing continues if the publisher is down, but configuration changes and new device registrations requiring database writes fail until the publisher returns.

Cisco Unified Survivable Remote Site Telephony (SRST) registers IP phones to a local router when WAN to the CUCM cluster is lost; SRST is configured with max-ephones/max-dn and uses a configured SRST reference from the device pool.

Device pool determines: region (codec between sites), location (call admission control bandwidth), SRST reference, date/time group, and network locale; region controls codec selection, location controls bandwidth allocation for CAC.

Locations-based call admission control counts bandwidth per location; Enhanced Locations CAC uses a hub/spoke or MPLS topology with a location for each site, enforcing per-link bandwidth limits and allowing calls to be rejected with a configured CAC rejection tone.

Intercluster Lookup Service (ILS) replicates dial plan and other cluster data across clusters; it uses TCP 7501 (ILS) and requires a hub cluster configured as the ILS hub, with spoke clusters connecting to the hub.

Cisco Expressway-C and Expressway-E provide Mobile and Remote Access (MRA): Expressway-C sits inside the network facing CUCM, Expressway-E in the DMZ; the traversal zone between them uses TCP 7001 (TLS) for signaling and UDP 50000-59999 for media.

Cisco Unified CM OVA deployment requires a fixed disk layout: 1 vCPU/2 vCPU/4 vCPU options for small to large; the standard CUCM 12.5/14 OVA offers 1,000, 2,500, 7,500, 10,000, and 20,000 user templates, and CPU reservation must match the template.

Cisco Emergency Responder (CER) tracks phone location via switch port and MAC address; it uses an SNMP query to the switch to find the port, and its location-based ERL (Emergency Response Location) maps to the correct PSAP.

Cisco Unity Connection: a single Connection cluster supports up to 20,000 users (active/active with two nodes); each node can handle 20,000 users, but the cluster maximum is 20,000 users with both nodes active.

Unity Connection call handlers vs. system call handlers vs. directory handlers: call handlers answer and route calls, directory handlers provide dial-by-name, and interview handlers collect caller input; routing rules match dialed number, caller ID, or forwarding station.

Cisco IM and Presence Service: a presence redundancy group pairs two nodes (one active, one standby) for high availability; each presence node supports up to 20,000 users, and a cluster supports up to 40,000 users with two presence redundancy groups.

Cisco Expressway MRA requires: Unified CM, Expressway-C, Expressway-E, Cisco Jabber or Webex App clients, and a valid CA-signed certificate on Expressway-E; the domain used by clients must be resolvable internally and externally (split DNS).

Cisco Jabber service discovery: _cisco-uds._tcp SRV record for on-premises CUCM, _cuplogin._tcp for Unity Connection, and _collab-edge._tls for MRA via Expressway; the client tries _cisco-uds first, then _collab-edge.

Cisco Webex Meetings/Webex App hybrid services: Calendar Connector, Directory Connector, and Hybrid Call Service (Call Connector) integrate on-premises CUCM with the Webex cloud; Hybrid Call Service requires Expressway-C/E and a registered CUCM.

Cisco Unified CM IM and Presence uses SIP for presence federation; intercluster presence peering uses SIP over TLS (port 5062) between presence nodes in different clusters.

Cisco Unity Connection SMTP integration uses port 25 for outbound and configures a smart host; for Exchange integration, Unified Messaging uses EWS (Exchange Web Services) over HTTPS, and single inbox requires Exchange 2013 or later.

Cisco Meeting Server (CMS) provides on-premises conferencing: it uses SIP (port 5060/5061) for call signaling, and its API (port 443) is used to create spaces, coSpaces, and to integrate with CUCM via a SIP trunk.

SIP INVITE contains: Request-URI, Via (transport and branch), From, To, Call-ID, CSeq, Contact, and Max-Forwards; the SDP offer in the INVITE body lists codecs and RTP media addresses/ports.

SIP response codes: 100 Trying, 180 Ringing, 183 Session Progress (with SDP for early media), 200 OK, 401/407 authentication challenge, 486 Busy Here, 488 Not Acceptable Here (codec mismatch), 503 Service Unavailable.

H.323 call signaling: Q.931 setup/connect messages over TCP 1720 for call setup, H.245 over TCP 1720 or a dynamic port for capabilities, and RAS over UDP 1719 for gatekeeper registration.

SIP trunk configuration in CUCM: a SIP trunk is associated with a route group, which is associated with a route list, which is associated with a route pattern; digit manipulation happens at the route pattern, route list, route group, or trunk level.

CUCM digit analysis: route patterns, translation patterns, and dial rules process digits; the most specific match wins (longer match, then explicit digit over wildcard, then route pattern over translation pattern).

SIP OPTIONS ping: CUCM sends OPTIONS to a SIP trunk to monitor its status; the trunk is marked down if no response is received within the configured retry timer, and the route list can then route to the next member.

H.225/Q.931 cause codes: cause 16 (normal call clearing), cause 17 (user busy), cause 34 (no circuit/channel available), and cause 47 (resource unavailable) are commonly mapped to CUCM cause values for SIP-to-H.323 interworking.

SIP early media: 183 Session Progress with SDP establishes one-way audio before answer; PRACK (RFC 3262) provides reliable provisional responses, and CUCM can be configured to send PRACK to the gateway.

CUCM call routing: a route pattern with the @ wildcard matches any dialed number; the # wildcard matches any single digit, and the X wildcard matches digits 0-9; the ! wildcard matches one or more digits.

Expressway-E in the DMZ requires: a public CA-signed certificate with the client-facing domain as a SAN, a traversal zone to Expressway-C, and static NAT to a public IP; the internal and external DNS must resolve the same Expressway-E FQDN.

Traversal zone ports between Expressway-C and Expressway-E: TCP 7001 for signaling (TLS), UDP 50000-59999 for media, and TCP 7400 for the traversal server; firewall rules must permit these in both directions.

Cisco Unified CM SIP trunk security: a secure SIP trunk uses TLS (port 5061) and SRTP for media; it requires a certificate trust store and a phone security profile with device security mode set to Encrypted or Authenticated.

Cisco Unified CM certificate types: tomcat (HTTPS/443), CallManager (SIP TLS/5061), TVS (phone trust verification), CAPF (certificate authority for phone LSC), and IPSec; the CallManager certificate must be trusted by the SIP trunk peer.

Cisco Jabber with MRA: the client authenticates to Expressway-E, which proxies to Expressway-C, which proxies to CUCM; the client uses the _collab-edge._tls SRV record for discovery and requires an internal CA-signed certificate on Expressway-C.

Cisco Unified CM security modes for phones: Non-secure, Authenticated (signaling integrity with TLS, media unencrypted), and Encrypted (TLS signaling and SRTP media); Encrypted requires a Locally Significant Certificate (LSC) from CAPF.

Cisco Expressway firewall rules: inbound from internet to Expressway-E on TCP 5060/5061 (SIP), TCP 8443 (HTTPS for MRA), and UDP 3478 (TURN); TURN is used for media traversal when direct media is not possible.

Cisco Unified CM IPSec: IPSec policies are configured in Cisco Unified OS Administration under Security > IPSec; they are used to secure signaling and media between CUCM clusters or between CUCM and gateways.

Cisco Collaboration Edge: Expressway-C and Expressway-E support Business-to-Business (B2B) calls via a neighbor zone to a third-party system; the B2B zone uses SIP over TLS and can be configured with a search rule to route calls.

Cisco Unified CM AXL API: uses SOAP over HTTPS (port 8443) with a WSDL; authentication uses an application user with the Standard AXL API Access role; the AXL schema version must match the CUCM version.

Cisco Unified CM Real-Time Monitoring Tool (RTMT): provides performance counters, alert history, and trace collection; the Perfmon counters include Cisco CallManager (registered phones, calls active) and Cisco SIP (SIP trunk status).

Cisco Unified CM CDR/CMR: Call Detail Records are written to the CUCM publisher and can be sent to a billing server via a CDR Management configuration; CAR (Cisco CDR Analysis and Reporting) uses the CDR database to generate reports.

Cisco Unified CM SNMP: SNMP v2c/v3 is configured in Cisco Unified Serviceability; the Cisco CallManager MIB and CISCO-CCM-MIB provide traps for phone registration and server status; SNMP is disabled by default.

Cisco Unified CM Bulk Administration Tool (BAT): imports CSV files for phones, users, and lines; the BAT process is: create a CSV file, validate it, insert it, and then run the job; BAT jobs can be scheduled.

Cisco Unified CM Prime Collaboration Assurance (PCA): monitors collaboration networks, provides dashboards for call quality, and uses CDR/CMR data plus SNMP to detect issues; PCA can be deployed as a physical or virtual appliance.

Cisco Unified CM CLI: the 'utils' commands include utils service (start/stop/restart), utils dbreplication (status/reset), utils system (restart/shutdown), and utils diagnose (test); file commands include file get/put for backups.

Cisco Unified CM backup: uses the Disaster Recovery System (DRS) on the publisher; DRS backs up the database, TFTP files, and platform configuration; the backup scheduler runs on the publisher and stores backups to a configured SFTP/FTP server.

Cisco Unified CM API rate limits: the AXL API has a throttling limit; excessive requests can trigger a 503 response; use the Platform API (port 8443) for service control and the AXL API for configuration changes.