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VoX What is X ? . VoX. VoFR – why?. FR is the most mature of PSNs many enterprises already have FR network convergence: infrastructure, management FR can be global price not dependent on distance typically pay for committed rate so get VoFR for free !. VoX. VoFR – how?.
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VoX VoFR – why? • FR is the most mature of PSNs • many enterprises already have FR network • convergence: infrastructure, management • FR can be global price not dependent on distance • typically pay for committed rate so get VoFR for free !
VoX VoFR – how? Frame Relay Data Link Connnection FRAD FRAD Network
VoX VoFR Protocols Audio Control & Management G.711 G.726 G.729 FAX FR Connection Management FR LMI Q.933 A FRF.11 Q.922 Switching and Processing Physical Layer (Serial Port)
VoX FRF-11 Requirements Service Class 1 Class 2 high speed links low speed links (64Kbps) Primary Payload Type Default Mandatory: Mandatory: Voice - EADPCM – G. 727 - CS ACELP - G. 729/ G. 729 Algorithm - Transmit rate 32 Kbps AnnexA - Receive rate 32 Kbps, 24 Kbps, 16 Kbps Other Voice Optional: Optional: -PCM - G. 711 ; - MP - MLQ G. 723 . 1 -ADPCM-G. 726 - LD - CELP - G. 728 Data Optional Optional Fax Optional Optional Signaled Payload Type Dial Digits Optional Mandatory CAS Mandatory Mandatory AIS Mandatory Mandatory Encoded FAX Optional Optional
VoX VoATM – why? • ATM is used in access and core networks • ATM supports QoS and so is more fitted for voice than other PSNs • convergence: infrastructure, management • carriers can deploy ATM to cabinets achieve pair-gain
VoX PublicATM Network PC VoATM – how? FAX PBX E1 Bridge/Router ETH 2xE1 Headquarters FAX E1 E3 E1 PBX PBX E1 ETH E1 ETH Bridge/Router ETH Bridge/Router E1 ManagementStation PBX
VoX VoATM Protocols Audio Signaling & Management ATM Connection Management G.711 G.726 G.728 G.729 FAX ATM UNI 3.1 SSCF Q.2130 Proprietary Voice Protocol SSCOP Q.2110 AAL5 AAL1/AAL2 ATM Layer
VoX VoATM Options • AAL1 unstructured circuit emulation (CES) • AAL1 structured circuit emulation (CES) • AAL1 dynamic bandwidth allocation (DB-CES) • AAL2 variable bit rate VoATM • AAL5 proprietary variable bit rate VoATM
VoX IWF Functionality for ATM Trunking Call Handling CAS Signaling IWF-IWF Signaling ATM Signaling/NM for Provisionning IWF-IWF CAS/DTMF Signaling Nx64 Kbps CAS Supervisory & DTMF Address Signaling Mapping Function Voiceband Processing DSS2 - Echo Cancellation - Idle Pattern Detection - Silence Suppression - Bad cell/frame interpolation - Voice Compression - Fax/modem detection - Fax/modem relay AAL1/2 SAAL AAL1/2 ATM AAL2 PHY ATM Interface Synchronuous Timing PHY T1/E1 PBX
VoX VoIP – why? • IP coverage has become universal • price not dependent on distance may not be dependent on duration • new features possible • web call centers • whiteboard • video conferencing
VoX VoIP protocols Once upon a time Unix users conversed over LANs first official VoIP was VocalTec first standard was H.323 suite IETF came up with SIP sometimes MGCP or MEGACO enough
VoX H.323 vs SIP SIP • user agent (UAC,UAS) • GW • conferencing • registrar, redirect server • proxy • SDP • extensions H.323 • terminal • GW • MCU • gatekeeper • H.245 channel • audio, video, data
VoX Some ITU-T VoIP Standards H.320: Multimedia conferencing on ISDN H.321: H.320 over ATM H.322: H.320 over iso-ethernet LANs H.323: Multimedia conferencing on Packet Nets H.324: Multimedia conferencing on POTS H.225 - Call Signaling, PDU, Packetization H.245 - System Control T.120 - Data and Conference Control
VoX Link Physical H.323 Protocols Call Establishment And Control Presentation speech coder DTMF Addressing Addressing H.225 RAS H.225 Q.931 DNS RTP/RTCP DNS H.245 UDP TCP IP
VoX H.323 Network H.323 Endpoint H.323 Gatekeeper H.323 Proxy GATEWAY H.320 (over ISDN) Switched Circuit Network (POTs & ISDN) Internet H.324 (over POTS) Speech-Only (telephones) H.323 Endpoint
VoX VoIP – SIP H.323 is a telephony-type protocol SIP is a more standard IP protocol (similar to http) INVITE sip:6455389@rad.co.il SIP/2.0 From: VoP student To: Yaakov (J) Stein Call-ID: 5551212@bynet-academy.co.il CSeq: 1 INVITE Subject: How to use SIP Content-Type: application/sdp ACK sip: vopstudent@bynet-academy.co.il SIP/2.0 etc.
VoX VoIP – SIP CONFERENCE MANAGEMENT APPLICATIONS MEDIA AGENTS CONFERENCE SETUP AND DISCOVERY CONFERENCE CONTROL AUDIO VIDEO SHARED APPS SDP RTP RTCP DISTRIBUTED CONTROL RELIABLE MULTICAST RSVP SAP SIP HTTP SMTP UDP TCP UDP IP and IP MULTICAST Link Physical
VoX MGCP and MEGACO MEGACO • MG, MGC • termination • context (N terminations) • signals (MGC->MC) • events (MG-> MGC) • text or binary grammar • SDP • even more packages MGCP • MG, MGC • endpoint • connection (2 endpoints) • signals (MGC->MC) • events (MG-> MGC) • text grammar • SDP • packages
VoX VoDSL – why? • DSL uses existing under-utilized last-mile • residential customers already universally connected • can converge telephony and Internet • voice is the killer-app, voice supplies revenues • CLECs can compete with ILECs w/o rebuilding • CLECs need to purchase far fewer Class-5 switches • new features can be offered
VoX VoDSL – how? ATM V.5.2 Voice Gateway PSTN Public ATM Network ATM DSLAM BAS ATM IP ATM xDSL Internet IAD ATM xDSL IAD
VoX TDMoIP – why? • VoIP has very high overhead, due to session level encapsulation • VoIP only handles a small number of the PSTN features • VoIP introduces a large amount of delay • VoIP degrades voice quality • VoIP is expensive and requires “forklift upgrade” • TDMoIP adds low overhead, since it transfers trunks • TDMoIP is transparent to PSTN signaling • TDMoIP introduces minimal delay • TDMoIP does not compress voice, so only degradation is delay • TDMoIP is inexpensive and evolutionary
VoX TDMoIP – how? TDMoIP uses UDP/IP TDMoIP adds an additional pseudowire header TDMoIP uses AAL1 or AAL2 adaptation 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 LRZ length sequence number FORMID
VoX VoCATV – why? • CATV is existing under-utilized infrastructure • in many areas majority of residential customers already connected • can converge TV, Internet and telephony • cable full-duplex upgraded for pay-per-view • can deliver 30 Mbps DS over 50 KM range • competes with DSL access
VoX Cable modems CABLE MODEM CMTS CABLE MODEM OPTICAL FIBER NODE CATV HEADEND fiber coax COAXIAL AMPLIFIER CABLE MODEM shared BW CABLE MODEM
VoX Cable modems - continued In US: DOCSIS - Data Over Cable System Interface Specification • Specification for high-speed data-over-cable systems • IP based • DOCSIS 1.0 designed for transparent bi-directional traffic • DOCSIS 1.1 enhancements: • BW management / Prioritization features (QoS) • Higher security Cable modems do not monitor each other so Ethernet not possible Adopted by ITU as J.112
VoX Multiple Standards Incumbent standard for set-top boxes in Europe DVB/DAVICDigital Broadcast Video / Digital Audio Video Council This standard is based on ATM DVB2.0 “EuroModem” adopted by ETSI as ETS-300800 European Cable Consortium supports EuroDOCSIS DOCSIS with DVB-compliant physical layer IEEE developed 802.14 not gained support, but may be the next generation
VoX VoCATV CableLabs added other protocols for VoCATV • NCS Network Call Signaling • MGCP • IPSec authentication (DES) • Optional fax-relay service And additional features • BTI Broadband Telephony Interfaces billing • 4 hour lifeline service