Monday, November 23, 2009

VoIP Phones - How Voice over IP Works?

Actually, the integration of voice and data on one network is an old idea, as long solutions have emerged from different manufacturers, using multiplexers, allow the use of WAN data of companies (typically point connections to-point and frame-relay) for the transmission of voice traffic. The lack of standards and long repayment period of such solutions has ensured widespread deployment of them.

Undeniably, the definitive establishment of the IP protocol from the domestic business areas and the emergence of a standard, VoIP could not be expected. The emergence of VoIP along with the lowering of the DSP's (Digital Signal Processor), which are key in the compression and decompression of voice, are the elements that have made possible the launch of these technologies. For this boom there are other factors, such as the emergence of new applications or definitive commitment VoIP vendors like Cisco Systems and Nortel-Bay Networks. Moreover phone operators are offering or plan to offer in the near future, quality IP services to businesses.

It said so far, we see that we can find three types of IP networks:

* Internet. The current state of the network does not allow professional use for voice traffic.

* Public IP Network. The operators offer businesses the connectivity to interconnect their local area networks as IP traffic is concerned. It can be considered as similar to the Internet, but with a higher quality of service and significant security enhancements. There are operators even offer guarantees low delay and / or bandwidth, making them very interesting for voice traffic.

* Intranet. The IP network implemented by the company itself. Usually consist of several LAN (switched Ethernet, ATM, etc. ..) that are interconnected through WAN Frame-Relay/ATM type, point to point lines, ISDN remote access, etc.. In this case the company has control over virtually all network parameters, making it ideal for use in the transport of voice.

Due to the existing standard of ITU-T H.323, which covered most of the requirements for the integration of voice, it was decided that H.323 as the basis of VoIP. Thus, VoIP is seen as a clarification of H.323, so that in case of conflict, in order to avoid a gap between standards, it was decided that H.323 would have priority over VoIP. The VoIP has focused on ensuring interoperability between equipment from different manufacturers, fixing issues such as silence suppression, voice coding and routing, and establishing new elements to enable connectivity to the traditional telephone infrastructure. These elements are basically concerned with directory services and the transmission of signaling tone multifrequency (DTMF).

Also read my latest hub:

Why should I use a VoIP phone when I have a traditional phone available?

1 comment:

  1. Thanks for this article. I find it a pain to locate good quality
    guidance out there when it comes to this topic.

    ReplyDelete

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