Practical Voice and Video over IP Training Course

Objectives:

• Clarify the operation of circuit-switched networks.
• Highlight the distinctions between circuit-switched and packet-switched networks.
• Detail the fields and flags within the IP header, including the DSCP field.
• Discuss and quantify the requirements for voice compression and latency within an IP network.
• Identify CODECs used for voice and video compression, such as G711, G729, and H.261/3/4.
• Examine the fields of the Real Time Transport Protocol (RTP) and Real Time Control Protocol (RTCP), including DTMF tone transmission.
• Determine bandwidth requirements for different voice compression algorithms.
• Illustrate the necessity of security and encryption in VoIP environments.
• Outline the H.323 protocol stack.
• Explain call setup and signalling protocols (H.225).
• Describe H.245, fast start mechanisms, and H.245 tunnelling.
• Detail SIP call establishment procedures.
• Explain the role of SIP Servers.
• Describe and explain the Session Description Protocol (SDP).
• Discuss Soft Switching concepts, including MGCP and H.248.
• Explain the function of SCTP in backhauling signalling messages.
• Emphasize the impact of network delay and the critical need for QoS.
• Differentiate between reservation-based and prioritization-based QoS in IP networks.
• Describe the application of IntServ and RSVP for QoS.
• Explain the use of TOS and DiffServ in QoS implementations.
• Justify the need for multiple queues and intelligent packet scheduling at router and switch interfaces.
• Describe MPLS usage for delivering QoS in WAN environments.
• Explain the deployment of VLANs to deliver QoS in LAN environments.

Practical Exercises:

• Lab Exercise 1: Implementing Practical VoIP in the LAN.
• Lab Exercise 2: Construct an IP network, place calls, and analyze RTP packets using Wireshark.
• Lab Exercise 3: Place calls and inspect SIP packets using Wireshark.
• Lab Exercise 4: Place calls and examine H.323 packets using Wireshark.
• Lab Exercise 5: Establish calls between PSTN and IP networks.
• Lab Exercise 6: Configure QoS and place calls to observe the effects.
• Lab Exercise 7: Implement Security and VoIP measures.

Equipment used in Practical Sessions:

• Cisco 2600 and 2800 series voice-capable routers, along with four Cisco ASA 5505 units. IP telephones, softphones, and analogue telephones as needed. SIP client and server software as required.