Convergence of voice and data is now a common place mainstream technology. Our Voice Over IP course investigates the characteristics of voice transmission and then studies the impact on IP networks. Practical sessions with soft phones, hard phones and gateways allow the students to see all aspects of VoIP. Network analysers are used to study packets on the wire.

Utbildningsmål

• Describe the issues of voice and data convergence.
• Describe techniques, which can be used in IP to provide low uniform delay.
• Evaluate VoIP technologies.
• Design data networks, which will support voice.

Förkunskaper

TCP/IP foundation for engineers
Intro to data communications & networking

Målgrupp

Anyone working in the field of networking or telecommunications.

Innehåll

• What is VoIP

Voice over IP, brief review of IP, brief review of telephones and voice.

• Configuring IP softphones

What are softphones? Downloading, installing.
Hands on Building the base IP network, a simple VoIP call with softphones, Internet telephony.

• Addressing

E164, FQDN, IP addresses, URIs, DNS, SIP addressing, H.323 addressing.

• VoIP issues

Bandwidth, Delay, Jitter, digitising voice, digitisation steps, coding, quality issues, MOS, voice compression, silence suppression, packetising voice, prioritising voice, jitter buffers.
Hands on Simple packet analysis.

• Architectures

Desktop, backbone, gateway, hard phones, PoE, integrating phones and PCs, carriers, Softswitches.
Hands on Integrating Softphones, hard phones and analogue phones.

• IP performance and QoS

ITU delay recommendations, IP DSCP field, DiffServ, IP precedence, queuing strategies; FIFO, WFQ, custom, priority, RED, LLQ.

• VoIP protocol stack

RTP, RTCP, mixers and translators, RSVP. Bandwidth, Erlang models, link layer overhead.
Hands on Calculating VoIP bandwidth, analysing RTP packets.

• ITU Recommendation H.323

Architecture, protocols, terminals, Call setup, Gatekeepers, gateway discovery, H.323 registration with a gatekeeper.
Hands on PC to PC using H.323.

• IETF – Session Initiation Protocol

What is SIP? SIP protocol stack, SDP, Sip architecture, SIP messages, Initial SIP phone startup, SIP servers, proxy server, redirect server.
Hands on PC to PC using SIP.

• Carrier networks

Signalling systems, SS7, media gateways, Media gateway controllers, signalling gateways, MGCP, Megaco, SIGTRAN.
Hands on PSTN interworking.

• Video over IP

Video components, digital video, pictures and audio, video codecs, issues and solutions, video conferencing, multipoint video conferencing, video protocol stack.

• Appendix 1: Multicasting.
• Appendix 2: Voice/data integration without IP.