Practical Voice and Video over IP Training Course

Objectives:

• Clarify the operation of circuit-switched networks.
• Distinguish between circuit-switched and packet-switched networks.
• Detail the fields and flags within the IP header, including the DSCP field.
• Articulate and quantify the necessity for voice compression and latency management in IP networks.
• Recognise CODECs utilised in voice and video compression, such as G711, G729, and H.261/3/4.
• Identify and elucidate the fields of the Real-Time Transport Protocol (RTP) and Real-Time Control Protocol (RTCP), including the transmission of DTMF tones.
• Compute bandwidth requirements for various voice compression algorithms.
• Articulate and demonstrate the imperative for security and encryption within VoIP.
• Outline and clarify the H.323 protocol stack.
• Explain call setup and signalling mechanisms (H.225).
• Clarify H.245, fast start procedures, and H.245 tunnelling.
• Describe and explain SIP call setup processes.
• Outline and clarify SIP Servers.
• Explain Session Description Protocol (SDP).
• Clarify Soft Switching, encompassing MGCP and H.248.
• Explain the role of SCTP in backhauling signalling messages.
• Emphasise the significance of network latency and the need for Quality of Service (QoS).
• Distinguish between reservation-based and prioritisation-based QoS in IP networks.
• Outline the utilisation of IntServ and RSVP for QoS.
• Explain the application of TOS and DiffServ in QoS.
• Justify the need for multiple queues and intelligent packet scheduling at router/switch interfaces.
• Describe how MPLS delivers QoS in WAN environments.
• Explain how VLANs facilitate QoS in LAN environments.

Practical Exercises:

• Lab Exercise 1: Practical VoIP implementation within the LAN.
• Lab Exercise 2: Construct an IP network, place calls, and analyse RTP packets using Wireshark.
• Lab Exercise 3: Place calls and examine SIP packets using Wireshark.
• Lab Exercise 4: Place calls and inspect H.323 packets using Wireshark.
• Lab Exercise 5: Facilitate calls between PSTN and IP networks.
• Lab Exercise 6: Configure QoS and place calls to observe the effects.
• Lab Exercise 7: Explore Security and VoIP.

Equipment utilised in Practical Sessions:

• Cisco 2600 and 2800 series voice-capable routers, Cisco ASA 5505 [4 units], IP Telephones, softphones, and analogue telephones as needed. SIP client and server software as required.