© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Introduction to VoIP Building Scalable Dial Plans

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Outline Overview Numbering and Dial Plans Hierarchical Numbering Plans Internal Numbering and Public Numbering Plan Integration Scalable Dial Plans Scalable Dial Plan Attributes Enhancing and Extending an Numbering Existing Plan to Accommodate VoIP Accounting for Caller Mobility for 911 Services Summary Lesson Self-Check

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Numbering and Dial Plans Numbering plans assign telephone numbers to end devices or applications for current needs and future growth. Dial plans consist of summarized dialing patterns based on the implemented numbering plan. Dial plans may include use of access codes, area codes, specialized codes, and combinations of the numbers of digits that are dialed. Dial plans address overlapping number ranges through the use of site access codes.

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Span Engineering Numbering Plan LocationNumbering Plan Cicero xxx xxx xxx Woodridge xxx ORD xxx Dallas xxx xxx

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Span Engineering Dial Plan Span Engineering Dial Plan Requirements Each site is identified with single-digit access code. Intrasite dialing requires four-digit extension. Intersite dialing requires access code plus four-digit extension. Local PSTN dialing requires 10-digit number. Long-distance PSTN dialing requires 11-digit number.

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Hierarchical Numbering Plans

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Varying number lengths Specialized services Voice mail Necessity of prefixes or area codes International dialing consideration Challenges Associated with Integration

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Integrating Internal and Public Numbering Plans

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Span Engineering Integration of Internal and Public Numbering Plans Integrating PSTN for Backup Call Routing

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Dial plans contain specific dialing patterns for a user who wants to reach a particular telephone number. Dial Plans

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Need for a Scalable Dial Plan

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Logic distribution Hierarchical design Simplicity in provisioning Reduction in postdial delay Availability and fault tolerance Attributes of a Scalable Dial Plan

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Number Normalization

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v ANI: The calling party number ALI: A database record of telephone number-to-geographic location association; typically located in the PSTN PSAP: Normally a police or sheriff-run call center ERL: The area from which an emergency call is placed and to which a 911 Emergency Response Team (ERT) may be dispatched; used in VoIP mobility environments ELIN: A phone number that is used to route the emergency call to the local PSAP, and which the PSAP can use to call back the emergency caller; used in VoIP mobility environments MSAG: Maintained by a government agency; lists which PSAP serves a particular address range Selective router: A specialized telephone switch used for 911 that routes calls to the appropriate PSAP based on calling number (ANI) instead of called number CAMA: An analog phone trunk that connects directly to an 911 selective router, bypassing the PSTN Cisco Emergency Responder: A Cisco application used in a mobile VoIP environment to automatically track and update equipment moves and changes 911 Terms and Components

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Call Processing in a Nonmobile Environment Permanent user location: : 123 N. Main St, Bldg. A, Floor 3, Northwest Corner

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Call Processing in a Mobile VoIP Environment ERL 1: : 123 N. Main St., Bldg. A, Floor 3, Northwest Corner ERL 2: : 125 N. Main St., Bldg. D, Floor 1, Southwest Corner

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Summary Numbering plans define telephone numbers for voice endpoints and applications, whereas dial plans define call routing and digit manipulation. Overlapping number ranges are addressed through the use of site access codes. The associated attributes of a hierarchical numbering plan are simplified provisioning and routing, summarization, scalability, and management. These attributes provide minimal system and configuration impact, anticipated growth consideration, and conformance to public standards, where applicable. Varying number lengths, specialized services, voice mail, necessity of prefixes or area codes, and international dialing considerations are challenges associated with integrating an internal numbering plan with the public numbering plan.

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Summary (Cont.) Because implementing a scalable dial plan involves extensive call routing, it is important to understand a customer network topology, number dialing patterns, router and gateway locations, and traffic requirements. The required design-simplification attributes of a scalable numbering plan provide increased manageability and increased call service and delivery. Digit manipulation and the addition of technology prefixes are methods to extend and enhance VoIP numbering plans. Cisco Emergency Responder dynamically tracks the adds, moves, and changes of mobile VoIP users and replaces the ANI with the ELIN to identify the current location of the originator.

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