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VoIP – Case Studies. Duncan MacAuslan Task Coordinator - VoIP ITP Training 2006 14 September 2006. Layer. Protocols. Application. VoIP. Email. HTTP. ToIP. etc. SIP/H.323, G7xx. Session*. TCP/UDP. Transport. ISP/CSP. IP. Internet. Network Access. ADSL, Ethernet, WiFi. Carrier.
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VoIP – Case Studies Duncan MacAuslan Task Coordinator - VoIP ITP Training 2006 14 September 2006
Layer Protocols Application VoIP Email HTTP ToIP etc. SIP/H.323, G7xx Session* TCP/UDP Transport ISP/CSP IP Internet Network Access ADSL, Ethernet, WiFi Carrier IP Layered Model Service Provider End user purchased applications, VSP * - theoretically there is no session layer in the IP model, split here for clarity.
Three carrier models PBX PBX PSTN Where we are now! Transitionary mixture Traditional PSTN PBX PBX IP WAN Router/GW Router/GW PSTN core replaced by packet switching Soft-Switch Soft-Switch IP WAN Router Router Application Servers Full end to end IP network – the NGN
VoIP Models • Peer to peer • Conventional • Message • Phone out from IP to PSTN • Phone in from PSTN to IP • DID • Extension
Connecting a traditional phone to VoIP Phone/USB ‘dongle’ ADSL or cable Internet ATAs Broadband Wireless ATA – analogue telephone adaptor
IP handset connections Connected to PC by sound card, USB or ethernet ADSL or Cable to Internet Internet IP phones connected directly to local ethernet Broadband Wireless
Analogue Telephone Adaptor PSTN used when no connection to internet PSTN LAN Internet Router VoIP pathway
VoIP calls to users on same VSP network Internet Fred calls VoIP user Jill Call is routed across VSP’s network to internet gateway closest to Jill Routed across internet to VSP’s network VSP’s softswitch refers call to SIP server URI to find Jill’s current IP address. SIP server then drops out.
Outbound one-way VoIP service SIP used to map caller’s IP address and URI to gateway phone number Internet PSTN If gateway in Australia caller usually has nominated a local call zone. If gateway overseas caller must dial full e.164 code eg +61 2 9555 1234 even if called party is next door. The gateway could be anywhere in the world depending on best tariffs. If gateway overseas, 000, if allowed, will arrive on international trunk CLI will be that of a line on gateway, if overseas eg +1 123 555 555, not necessarily identifying caller.
Inbound PSTN to VoIP – DID model PSTN Internet Calling party dials VoIP user using PSTN number; routed across PSTN to VSP’s incoming gateway VoIP user is allocated PSTN number eg 02 95551234 VSP’s softswitch refers call to SIP server to map PSTN to URI and current IP address. SIP server drops out. Call is routed across gateway to internet
Inbound PSTN to VoIP – extension model PSTN Internet Caller dials VSP’s gateway using PSTN number 9555 1234 VoIP user allocated a extension eg 09137637 Routed across PSTN to VSP’s incoming gateway. When call established caller dials ‘extension’ 52341 using DTMF VSP’s softswitch refers call to SIP server to map extension to URI and current IP address. SIP server drops out. Call is routed across gateway to internet
VoIP to VoIP eg Skype Internet VSP2 VSP1 Phone out Phone in PSTN Red line where VSP1 user must use PSTN to call VSP2 user Green line shows how a Skype user calls a VSP2 user Purple shows how peering will avoid the PSTN – the NGN solution
Some IP telephony examples Operator 1 • targeted at any broadband customer nationally • launched early 2005 • new broadband churn processes, • power supply notice to users, • number allocation
Operator 2 • Wireless broadband voice Sydney and Melbourne metro coverage • Assessed numbering options, expected geographic but longer term will explore mobility capability, • radio links should create greater customer awareness of power issue • Endorsed third party VoIP provider over own network
Operator 3 • Existing experience with customers and billing in cellular market • Mass market (retail outlets and advertising) via any broadband link includes CE (process B) • FAQs include a number of quality and performance warnings, • numbers via 3rd party • ISDN aspiring to CCS7
Operator 4 • Triple play over cable with voice broadband and Pay TV • Regional Victorian focus • Agreed CE and customer advice warnings re • power, • temporary exemption from portability because of interface, • highly localised pricing attraction