Everyman IT

Info

• Level: Beginner
• Presenter: Eli the Computer Guy
• Date Created: August 8, 2010
• Length of Class: 60 Minutes

Tracks

• Telephone Systems

Prerequisites

• Introduction to Telephone Systems
• Introduction to Convergence

Purpose of Class

• This class discusses the basic components and requirements for a business or enterprise Voice Over IP telephone system.

Topics Covered

• VoIP Servers
• VoIP Clients
• Gateways
• Protocols
• Codecs
• Network Latency
• QOS
• Unified Communications

Class Notes

1. VoIP Servers
   1. VoIP Servers route calls like a traditional PBX
   2. There are proprietary and Open Source versions of VoIP Server software
2. VoIP Clients
   1. VoIP “phones” are all client computers
   2. Hard Phones are computers made to look like traditional phones
   3. Soft Phones are software that is installed on a computer so that the computer can be used as a phone
3. Gateways connect VoIP networks to the PSTN (Public Switched Telephone Network)
4. Protocols
   1. VoIP Systems use protocols for servers and clients to communicate
   2. SIP is a standards based protocol that numerous vendors use
5. Codecs are used to encode voice communication
   1. Codecs determine the Sound Quality and the Bandwidth usage of a call
   2. Most VoIP servers come with codecs that you can use without any extra fees.  If you need better codecs they can be purchased
6. Network Latency and QOS
   1. Network latency is the time it takes for data to get from point A to point B
   2. Standard telephones have a latency of 45ms, VoIP can have a latency of up to 75-100ms.
   3. QOS – Quality Of Service – is a feature of networking equipment that allows the equipment to prioritize network traffic based on what it is.
7. Unified Communications is the idea that computer programs and server should be able to work with telephone communications.

Resources