IP Telephony/IP telephony

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Question
Is IP telephony the same as VoIP?
What are the recommendations, improvements or ideas of the network infrastructure to be IP telephony readiness to prevent fixed voice line, broadband and TV services to be affected and what to do when it occurs?

Answer
Yes, IP telephony is the same as Voice Over IP (VoIP).

In order to have good voice quality you must have Quality of Service (QoS) turned on in your network switches and routers. This gives priority to voice traffic on your network and slows down (buffers) data traffic that is not time critical. For example, it does not matter if your new Email message comes 1 second later than it normally would. However, it does make a big difference if someone sends a large Email with an attachment and you do not have QoS turned on in your network. In that case 1 second or more of speech can get put in the waiting queue whilst the Email goes through. This does not lead to a good user experience. It sounds awful.

To read about QoS go to Wikipedia and look at DSCP:

http://en.wikipedia.org/wiki/Differentiated_services_code_point

Normally networks recommend using EF for Voice packets and AF23 for Signaling packets. Everything else like Email is marked as "Best  Effort".

If you have Cisco switches, here is a good guideline as to how to implement QoS using DSCP on your network:

http://www.cisco.com/en/US/tech/tk543/tk757/technologies_tech_nota00800949f2.sht

Hope this helps you get started.

IP Telephony

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Gerry Magill

Expertise

I am a Software Architect employed by a large multi-national communications company providing VoIP and tradtional TDM communications to Enterprise customers.

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Past/Present clients
IBM, SBS, Siemens, KPMG, Bank Berlin, Commerzbank

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