 lmi command, 404 credentials command, 560 debug ip policy command, 204 cross-stack EtherChannel, 75 debug ppp authentication command, 447 crossbar fabric bus debug tftp events command, 568 defined, 234 debug voip dialpeer command, 569 module support, 240 debugging PPP authentication, 444 crossbar switching bus, 233 dedicated port mode, 287 crossover mode (FEX), 290 dedicated rate-mode, 287-290 CSMs (Content Switching Modules), 231, 246 default route CSU/DSU (Channel Service Unit/Data Service defined, 109, 114 Unit) IP routing table, 114 add/drop, 342 default-metric command, 150, 152 configuring, 370 define interface-range command, 320 defined, 345 deleting access lists, 418, 424 integrated, 369 demarcation point, 345 loopback tests, 367-369 deny clause (route maps), 199 performance monitoring and, 362 description command, 321, 544 troubleshooting, 371-374 designated bridges, 89 CUCM (Cisco Unified Communications designated ports, 89 Manager), 526, 529 designated router (DR), 138 CUCME (Cisco Unified Communication designing networks (see network designs) Manager Express), 529 destination-pattern command, 552, 554, 566 CUE (Cisco Unity Express), 529 DHCP protocol custom queuing, 582 IP addresses and, 650 customer premises equipment (CPE), 345 small office VoIP example, 537 cut command (NX-OS), 278 dial peers Cyclic Redundancy Check (CRC), 358 functionality, 551 Cyclic Redundancy Check 6-bit (CRC6), 363 pattern matching, 554 POTS example, 551-553 troubleshooting, 569 VoIP example, 553 D (data) bus, 234 dial plans, 542 D-channels, 347 Dialed Number Identification Service (DNIS), D4 framing, 360 DACCS (Digital Access Cross-Connect diff command (NX-OS), 278 System), 345 differential service code point (DSCP), 579 data channels, 347, 357, 524 differential services, 578-581 data communication equipment (DCE), 394, Digital Access Cross-Connect System (DACCS), 345 data link control identifier (DLCI), 388, 401 Digital Signal 3 (see DS3) data terminal equipment (DTE), 394, 395 Index Digital Signal Processors (DSPs), 529 dig