Tuesday, November 17, 2009

What is Unified Communications?

Unified Communications is defined as the process in which all means of communication, communication devices and media are integrated, allowing users to be in touch with anyone, wherever they are, and in real time.

The objective of Unified Communications is to optimize business procedures and boost human communications by simplifying processes.

Read more about Unified Communications.

What are the benefits of an IP PBX?

  • Much easier to install & configure than a proprietary phone system
  • Easier to manage because of web based configuration interface
  • No need for separate phone wiring
  • Allows users to hot plug their phone anywhere in the office - users simply take their phone, plug it into the nearest ethernet port and keep their existing number!
  • Allows easy roaming - calls can be diverted anywhere in the world because of the SIP protocol characteristics
  • Significant cost reduction by leveraging Internet
  • SIP standard eliminates proprietary, expensive phones
  • Scalable
  • Better reporting
  • Better overview of system status and calls
  • More IP PBX benefits

What are the benefits of an IP PBX?

  • Much easier to install & configure than a proprietary phone system
  • Easier to manage because of web based configuration interface
  • No need for separate phone wiring
  • Allows users to hot plug their phone anywhere in the office - users simply take their phone, plug it into the nearest ethernet port and keep their existing number!
  • Allows easy roaming - calls can be diverted anywhere in the world because of the SIP protocol characteristics
  • Significant cost reduction by leveraging Internet
  • SIP standard eliminates proprietary, expensive phones
  • Scalable
  • Better reporting
  • Better overview of system status and calls

What is H323?

H323 is a set of standards from the ITU-T, which defines a set of protocols to provide audio and visual communication over a computer network.

H323 is a relatively old protocol and is currently being superceded by SIP – Session Initiation Protocol. One of the advantages of SIP is that its much less complex and resembles the HTTP / SMTP protocols.

Therefore most VOIP equipment available today follows the SIP standard. Older VOIP equipment though would follow H 323.

What do the terms FXS and FXO mean?

FXS and FXO are the name of ports used by Analog phone lines (also known as POTS - Plain Old Telephone Service) or phones.

FXS - Foreign eXchange Subscriber interface is the port that actually delivers the analog line to the subscriber. In other words it is the ‘plug on the wall’ that delivers a dialtone, battery current and ring voltage.

FXO - Foreign eXchange Office interface is the port that receives the analog line. It is the plug on the phone or fax machine, or the plug(s) on your analog phone system. It delivers an on-hook/off-hook indication (loop closure). Since the FXO port is attached to a device, such as a fax or phone, the device is often called the ‘FXO device’.

FXO and FXS are always paired, i.e similar to a male / female plug.

Without a PBX, a phone is connected directly to the FXS port provided by a telephone company.

What is FOIP - Fax over IP?





FOIP stands for Fax over IP and refers to the process of sending and receiving faxes via a VOIP network.

Fax over IP works via T38 and requires a T38 capable VOIP gateway as well as a T38 capable fax machine, fax card or fax software. Fax server software that can talk 'T38' allows sending and receiving faxes directly via a VOIP gateway and, consequently, does not need any additional fax hardware.

3CX includes a T38 compatible network fax server in its 3CX Phone System for Windows. Faxes are converted to PDF files and forwarded via email. Outbound faxes are sent via Microsoft Fax from anywhere in the network. Other fax servers currently in the market require the use of separately licensed and expensive Dialogic SoftIP drivers.

How does FAX work in VOIP environments?

How does FAX work in VOIP environments?

FAX was designed for analog networks, and does not travel well over a VOIP network. The reason for this is that FAX communication uses the signal in a different way to regular voice communication. When VOIP technologies digitize and compress analog voice communication it is optimized for VOICE and not for FAX. Subsequently, there are a number of things you need to take note of when you move to a VoIP Phone System.

If you want to continue using your old fax machine, and you want to connect to your VoIP phone system, its best to use aVoIP Gateway and an ATA that supports T38. T38 is a protocol designed to allow fax to 'travel' over a VoIP network. An example configuration of such a setup can be found here

It is also possible to convert to computer based fax and choose a VoIP phone system that supports fax. 3CX Phone System for Windows includes a full featured fax server that is able to receive faxes and forward them in PDF format to e-mail. Faxes can be sent from anywhere in the network using theMicrosoft Fax client & fax server (which comes free with Windows Server 2003 and 2008)

Another way to deal with fax when you switch to voip are to connect the fax machine directly to the existing analog phone line and bypass your VOIP system.