With different types of external equipment appearing in the market to accommodate people's communications needs, VoIP telephony was born. Voice over Internet protocol or VOIP telephony is today's most popular service that allows users to make and terminate calls over the Internet to landline units. Computer telephony has increased over the years. Technology has allowed the computer and telephone to share data more conveniently and with good quality. Because of the integration of contact channels like email, fax, voice and web service with computer systems, computer telephony has expanded.

With different types of external equipment appearing in the market to accommodate people's communications needs, VoIP telephony was born. Voice over Internet protocol or VOIP telephony is today's most popular service that allows users to make and terminate calls over the Internet to landline units. Apart from lower costs, voip telephony offers the same quality service as the traditional landline calls.

Telephony uses different protocols in transmitting calls between two different sets of networks. While the IP telephony uses the TCP/IP protocols of the Internet, old telephone service uses public switched telephone network (PSTN). This can bring a lot of problems for the users like loss of data, inability to transmit good voice quality and frequent termination of calls.

To solve the problem of the delay in voice transmissions, two standards have been used for VOIP telephony: ITU-T H.323 and the IETF Session Initiated Protocol (SP). These protocols give the same end-user service but differ in their approach to signaling functions. H.323 is the current standard for sending voice and video using the IP on the public Internet and within an intranet. However, SP is becoming a threat to H.323 protocol users.

SP uses the benefits of IP by using a HTTP-like protocol that makes it less complex. It uses textual encoding so it is much easier to extend in terms of applications, debug and process through text-processing programs. This, in turn, provides users and organizations with better control over their voice and data communications relay.

Apart from these two protocols, there is another one used online and it is called the Media Gateway Control Protocol (MGCP). MGCP is a protocol being used to control (VoIP) Gateways from call agents. This means, MGCP acts as a control tower for the existing SP or H.323 protocol. As the last two protocols give call control functionality, MGCP manages data establishment in the media gateways.

What makes MGCP more superior to SP protocols is its adaptability to other gateways and Ips. SP is a peer-to-peer protocol, which means it only works best if the external equipment also uses SP. MGCP can work within the same network and beyond the limitations of other protocols online. The result is a faster and clearer delivery of voice transmission over the Internet.

However, MGCP is not meant to replace SP or H.323 protocols. SP and H.323 provide symmetrical setup or control. MGCP then divides the call setup or control and the media establishment functions, making for an easier and clearer data flow.

SP has been lauded as the next best thing for VoIP telephony. With the possibilities of web integration, instant messaging capabilities and the flexibility of new applications, it promises to have great potential in replacing the H.323 standard. For now, SP and MGCP are better off working together to serve the VoIP telephone users.

By Kevin Whales