© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v VoIP Signaling and Call Control Introducing H.323

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Outline Overview H.323 and IP Functional Components of H.323 H.323 Call Establishment and Maintenance Call Flows Without a Gatekeeper Call Flows with a Gatekeeper Call Flows with Multiple Gatekeepers Multipoint Conferences Summary Lesson Self-Check

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v H.323 and Associated Recommendations

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v H.323 Adapted to IP

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v H.323 Terminals

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v H.323 Gateways

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v IP-to-IP Gateways

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v H.323 Gatekeepers

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

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Component Relationships for Call Establishment and Management Endpoint (gateway) to endpoint (gateway) Endpoint (gateway) to gatekeeper Gatekeeper to gatekeeper

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

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v H.323 Basic Call Setup

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v H.323 Fast Connect Call Setup

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Finding and Registering with a Gatekeeper

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Call Flow with a Gatekeeper

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Gatekeeper-Routed Call Signaling

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Scalability with Multiple Gatekeepers

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Call Flow with Multiple Gatekeepers

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

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Summary H.323 includes recommendations for capabilities exchange, call setup, and call routing. An H.323 environment includes terminals, gateways, gatekeepers, and components for multipoint conferences. Although H.323 is based on a distributed call control model, it often uses some components of a centralized call control model to enhance scalability. When a gatekeeper is used in an H.323 design, RAS signaling is used for communication with endpoints and other gatekeepers.

© 2006 Cisco Systems, Inc. All rights reserved. CVOICE v Summary (Cont.) IP-to-IP gateways facilitate the connection between two VoIP networks. A basic or Fast Connect H.323 call setup does not require a gatekeeper. Adding a gatekeeper to the H.323 network enhances scalability by centralizing call address resolution. Multiple gatekeepers can be used to build large VoIP networks. H.323 defines three types of multipoint conferences: centralized, decentralized, and ad hoc.

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