Practical Voice and Video over IP Training Course

Objectives:

• Explain the operation of circuit switched networks.
• Contrast the differences between circuit switched and packet switched networks.
• Explain the fields and flags within the IP header – including the new DSCP field.
• Explain and quantify the need for voice compression and delay in an IP network.
• Identify the CODEC’s used in voice and video compression – e.g. G711, G729 and H261/3/4.
• Identify and explain the fields of the Real Time Transport Protocol and Real Time Control Protocol – including carrying DTMF tones.
• Calculate bandwidth requirements for various voice compression algorithms.
• Explain and demonstrate the need for security and encryption within VoIP.
• Describe and explain the H.323 protocol stack.
• Describe and explain call setup and signalling (H.225).
• Describe and explain H.245, fast start and tunnelling of H245.
• Describe and explain SIP call setup.
• Describe and explain SIP Servers.
• Describe and explain SDP.
• Describe and explain Soft Switching – including MGCP and H248.
• Describe and explain the use of SCTP in backhauling signalling messages.
• Describe and explain the importance of network delay and the need for QoS in the network.
• Describe and explain the differences between reservation and prioritisation QoS in an IP Network.
• Describe the use of IntServ and RSVP in QoS.
• Describe the use of TOS and DiffServ in QoS.
• Describe and explain the need for multiple queues and intelligent scheduling of packets at router/switch interfaces.
• Describe the use of MPLS to deliver QoS in the WAN environment.
• Describe the use of VLAN’s to deliver QoS in the LAN environment.

Practical Exercises:

• Lab Exercise 1: Practical VoIP in the LAN.
• Lab Exercise 2: Build IP network, make calls and examine RTP packets using Wireshark.
• Lab Exercise 3: Make calls and examine SIP Packets using Wireshark.
• Lab Exercise 4: Make calls and examine H323 Packets using Wireshark.
• Lab Exercise 5: Calls between PSTN and IP Networks.
• Lab Exercise 6: Configure QoS and make calls to examine effects.
• Lab Exercise 7: Security and VoIP.

Equipment used in Practical Sessions:

• Cisco 2600 series and 2800 series voice capable routers and Cisco ASA 5505 Firewalls. IP Telephones, softphones and analogue telephones as required. SIP client and server software as required.