© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Dial Plans on Cisco IOS Gateways Introducing Dial Plans

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Defining Dial Plans A dial plan defines how calls are interconnected: Endpoint addressing: Internal destination accessibility is provided by assigning directory numbers to all endpoints. Call routing and path selection: Different paths can be selected to reach the same destination. Digit manipulation: Manipulate digits prior to or after a routing decision has been made. Calling privileges: Different groups of devices can be assigned to different classes of service, by granting or denying access to certain destinations. Call coverage: Special groups of devices can be created to handle incoming calls for a certain service according to different rules, avoiding dropped calls.

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Defining Dial Plans (Cont.) Dial Plan ComponentCisco IOS GatewayCisco Unified CallManager Endpoint addressingephone-dnDN Call routing and path selection Dial peers Route patterns, route groups, route lists, translation patterns, partitions, and calling search spaces Digit manipulation Voice translation profiles prefix, digit-strip, forward-digits, and num-exp Translation patterns, route patterns, and route lists Calling privilegesCOR and COR lists Partitions, calling search spaces, and FACs Call coverage Dial peers and call applications Line groups, hunt lists, and hunt pilots

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Defining Dial Plans (Cont.) IP WAN Phone Phone Phone Phone San Jose DID: XXX Chicago DID: XXX PSTN Router2 CUCME Router1 (H.323) CUCME = Cisco Unified CallManager Express

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Endpoint Addressing Directory numbers are assigned to end points (e.g., phones) Internal extensions are mapped to inbound PSTN calls –Often dependant on range of DID numbers –Auto attendant (AA) can be used for non-DID numbers The biggest challenge: creating an endpoint addressing scheme in multisite environments Primarily a Cisco Unified CallManager (Express) issue –Gateways simply route the call to the call handler –Exception: Gateway routes calls during SRST mode

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Overlapping Directory Numbers IP WANPSTN Phone Phone Phone Phone Router1 (H.323) Router3 CUCME Same range of directory numbers in two different sites San JoseChicago CUCME = Cisco Unified CallManager Express

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Call Routing and Path Selection Route the call depending on the dialed number. Select the appropriate path. Handled by dial peers on Cisco IOS gateways: –Inbound and outbound dial-peer matching determines the routing. –Complexity depends on design.

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Call Routing and Path Selection (Cont.) Inbound dial-peer matching: 1. Called number (DNIS) with incoming called-number. 2. Calling number (ANI) with answer-address. 3. Calling number (ANI) with destination-pattern. 4. For POTS: voice-port matches with dial-peer port. 5. Still no match: default dial peer 0 is used. Default outbound dial-peer matching (can be changed with dial-peer hunt command): 1. Called number (DNIS) with destination-pattern. 2. If multiple matches are found, the lowest preference wins. 3. If equal preferences are found, a random dial peer is chosen.

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Example: Toll-Bypass Routing IP WANPSTN Phone Phone Phone Phone Router1 (H.323) WAN is the preferred path with preference 1. 1 Router2 CUCME dial-peer voice 21 voip destination-pattern 2... preference 1 session-target ipv4: dial-peer voice 22 destination-pattern 2... prefix preference 2 port 0/0/0:23 If the WAN path is not available the PSTN path is used. 2 San JoseChicago CUCME = Cisco Unified CallManager Express

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Digit Manipulation Digit manipulation is closely connected with call routing and path selection. Inbound calls: –Called number needs to match outbound destination patterns. –Calling number needs to be dialable. Outbound calls: –Called number needs to satisfy PSTN requirements. –Calling number needs to be dialable, especially for emergency calls. Various commands are available for digit manipulation: –digit-strip, prefix, forward-digits, num-exp, voice translation-profile, and clid

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Calling Privileges Defines the destinations a user can call Often used to control telephony charges: –Blocks costly service numbers –Restricts international calls Often called Class of Service in PBX systems –Do not confuse with Layer 2 CoS. Implemented on Cisco IOS gateways using COR lists

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Call Coverage Call coverage ensures that all incoming calls are answered: For individuals: –Ring other phones if original called phone is not answering For user groups with pilot numbers: –Hunt through multiple phones –Ring multiple phones

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Phone Group Call Coverage (Cont.) Pilot Number 2000 User dials Pilot forwards the call to a group of phones. 2 Hunt algorithm picks a phone. 3

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v Summary A dial plan defines how calls are interconnected and routed. Endpoint addressing assigns directory numbers to endpoints. Call routing and path selection define where a call is routed to and usually depends on the called party number. The Digit manipulations feature ensures that numbers are presented in the correct format and is closely connected to call routing. Calling privileges define the destinations a user may dial. Call coverage ensures that incoming calls are not lost.

© 2006 Cisco Systems, Inc. All rights reserved.GWGK v