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RTMMoIP. Alfredo Terzoli / Mosioua Tsietsi. PLAN. Did you read the hand-out? A few important acronyms A call is more than a conversation: signalling! Timeline & general organization. A few acronyms for you to expand. PBX TDM PSTN T1 SS7 SIP. Solutions.
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RTMMoIP Alfredo Terzoli / Mosioua Tsietsi
PLAN • Did you read the hand-out? • A few important acronyms • A call is more than a conversation: signalling! • Timeline & general organization
A few acronyms for you to expand • PBX • TDM • PSTN • T1 • SS7 • SIP
Solutions • PBX : Private Branch Exchange • TDM : Time Division Multiplexing • PSTN : Public Switched Telephone Network • T1 : Trunk (level) 1 (ok, a bit strange); btw, in SA is normally E1 – 2 Mbps • SS7 : Signalling System 7 • SIP : Session Initiation Protocol
GnuGK GnuGK SER SER Asterisk Asterisk iLanga proxy iLanga proxy iLanga Core iLanga Core Legacy service provider use TDM network 1 TDM network 2 IP Network (Typically not the Internet)
GnuGK Asterisk Enterprise setting Local VoIP Endpoints SIP IAX H.323 MGCP Internet SER iLanga proxy Legacy PBX BRI PRI PSTN BRI PRI iLanga Core
VoIP signalling protocols • SIP: Session Initiation Protocol • IETF, Internet Engineering Task Force • H.323 • ITU, International Telecommunication Union • MGCP: Media Gateway Control Protocol - ITU • H.248/MEGACO: MEdia GAteway COntrol – ITU / IETF
SIP • In a sense the child of SMTP (Simple Mail Transport Protocol) and HTTP (Hyper Text Transfer Protocol) • Simple: • establishes the session only • uses SDP, for the description of the session • RTP for the transport of the media
User Agent UAS – server UAS – server UAC – client UAC – client
Some experiments • First, let’s get ourselves a SIP UA besides the one embedded in the telephone: • SJphone, www.sjlabs.com (& in the software resources for this module)
Experiments • Experiment 1: let’s call directly the hardphone, using its IP address • Experiment 2: let’s call the hardphone via iLanga, but without being part of iLanga (btw, this is the way the rest of the world can contact you) • Experiment 3: let’s join iLanga and start using the extensions and dialling out to the PSTN
Got a packet sniffer? • A good idea not to get bored with networks is to use a packet analyzer • If you don’t have one already, use WireShark, http://www.wireshark.org or in the software resources of this module
Rough timeline • First week: general VoIP concepts + SIP • your work: reading, playing with SIP UA, analyzing SIP and RTP packets • Second week: more SIP + Asterisk • your work: reading, experimenting with Asterisk; thinking about a service you want to create • Third week: more Asterisk, presentation of your service idea • your work: reading, starting putting together your service,