• Describe the requirements of providing a business with telephony services.
• Describe the role of PBXs.
• Recognise the role of mobile communications.
• Explain how VoIP and IPT work (at a simplified level).
• Describe the issues of providing a converged architecture.

Introduction
Main elements of the telephone network, digital and analogue handsets.

Media
Inside cabling, outside cabling. The Core Network, The Access Network, E1, 64 Kbit/s, N x 64 Kbit/s, Modems, ADSL, ISDN.

Numbering Plans
Telephony E.164, impact of numbering on businesses.

PABX
Key Telephone Systems, PABX facilities & features, Night Service, Fallback, Networking PABXs, Digital signalling overview.

Other Services
Centrex, ACD, CTI, Voice Mail, Automated Attendant Systems for PABXs, IVR, call management systems, call conferencing.

Mobile Communications
Wireless PABXs, Cellular Radio, Personal Communication Systems (PCS), DECT.

Case study
Providing telephony services for a company.

What is VoIP
What is VoIP?, What is IPT?

VoIP issues
Bandwidth, Delay, Jitter, signalling.

Voice
compression, packetising voice, comparison of techniques, MOS.

Architectures
Desktop, backbone, gateway, integrating phones and PCs.

IP performance and QoS
The need for QoS, prioritising voice.

H.323 versus SIP
Architectures, gateways, H.323 gatekeepers, SIP servers.

Integrating voice and data without IP
Data over voice, ISDN, voice over Frame Relay, voice over ATM.

Unified messaging
UM, other telephony applications.

Case study
Providing a converged solution