Transcript NGN 4
NGN Signaling Protocols PTCL Training & Development 1 SIGNALING PROTOCOLS IN NEXT GENERATION NETWORKS H.323, SIP, MGCP, SIG-TRAN ETC 2 NGN What it actually is….. A services oriented network – Focus is on services Separation of services from Call Control – Switching & connectivity headaches are no more in switches Services are independent of the Network – All services are independent of network control Open and Integrated – Multivendor environment designed by IUT & IETF 3 Distributed Intelligence of NGN Telephony world Internet world Centralized Intelligence Intelligence Driven by CPE Distributed & Effective Intelligence NGN Services 4 NGN Values Distributed and Open architecture Hierarchical architecture: four Layers It has an independent Network control Layer Easy Interfacing: for multiple vendor Gateways Based on Packet Switching and Standard Protocols It is a brand-new network integrating Voice, data and video services 5 Quantifying the NGN Network operators should: Build on Core Competencies related to traditional transport services Eliminate inefficient current servicespecific, proprietary solutions Enable carriers to deploy advanced services(all IP multimedia) 6 Signaling in Telecommunications • Signaling: used for establishing, controlling and monitoring the connections among networks and the end devices • Provides the means (paths, ways or directions) to exchange Connection-related information • Was simple in case of only voice • Became complex with Value Added & Supplementary services 7 Signaling in NGN • NGN signaling protocols: H.323, H.248, SIP, MGCP, Sig Tran, etc User to User • Media Gateway Controller to MGWC • User to MGWC and MGWC to user • User to Soft switch and vice-versa Signaling Transport Protocol: (Sigtran) PSTN to NGN Internetworking MGWC Protocol: H.248/MEGACO • Control of Media Gateways & media (voice, video) coding Session Description Protocol: SDP Characteristics of Audio/Video 8 H.323 Signaling in NGN • Version 1—June 1996 Multimedia conferencing on LAN, Defined network elements & Call model • Version 2—February 1998 More efficient procedures Authentication, encryption and security H.235 • Version 3– September 1999 Expanded supplementary services H.450 • Version 5– June 2003 Improved robustness, recovery from signaling errors Use of DNS, URLs within H.323 9 H.323 Functions and standard references • System and component Descriptions • Call Model Description • System Control H.323 H.323 Packetization, message formats, H.225(Q.931) channel negotiations H.245 • Audio Coding, Compression code standards, • Video Coding, compression G.711, G.722, G.723, G.729 H.261, H.263 ISDN(video phones) 10 H.323 Components • H.323 defines four major components for packet based communications: Terminal, Gateway, Gatekeeper, Multipoint Control Unit MCU Gateway Packet based N/W Terminal Gatekeeper Terminal Terminal 11 H.323 Components Terminals: Client endpoints in network say IP phones, PCs. Must support audio, G.711(64kbps) G.723.1, G.729, GSM & others Gateways: Supports inter-operatability, translation between H.323 & PSTN, Transmission formats, Audio/Video trans-coding, optional elements Gatekeeper: MCUs: Admission control, Bandwidth control, address translation, communicates using RAS (Registration, Admission and Status), manages all terminals, gateways, MCUs Supports multi-conferencing between 3 or more endpoints 12