allows every computer access to every other telephone trunk connections to the public computer in the company. By installing a telephone network. The IP PBX is a PBX VoIP Gateway in each office and connecting with VoIP, but it also has the ability to it to the office legacy PBX and to the data support VoIP over the Internet and Office to network, employees use the data network for Office VoIP. voice calls between offices. Advantages. Single cable infrastructure. The technology is transparent to the user, Advantages. Interoffice calls are free, since and requires minimum training. Future proof the company already has the bandwidth technology. between offices. The technology is transparent to the user, and requires Disadvantages. Primarily useful for minimum training. The only new equipment Greenfield sites, but can be adapted to work required is a gateway at each office. Voice with existing technology. quality is good, because the company has . control over the bandwidth. How VoIP works part 2 : The Protocols. Extra bandwidth may be Disadvantage. required between offices, which offset the I have made an assumption that both ends of savings. a VoIP telephone conversation are Other factors... The carrier providing the compatible. This compatibility only happens interoffice bandwidth will almost certainly if both ends agree to use the same protocol. offer an alternative solution including All manufacturers who claim to be management of the internal telephone producing industry standard voice over IP traffic. either support SIP or H.323 protocol. IP PBX A traditional Private Branch So what is H.323 ? Exchange (PBX) connects all the phones within an organization to the public Over the next few years, the industry will telephone network. Essentially IP PBX address the bandwidth limitations by replaces all the internal phones with VoIP upgrading the Internet backbone to telephones. The IP PBX has standard
allows every computer access to every other computer in the company. By installing a VoIP Gateway in each office and connecting it to the office legacy PBX and to the data network, employees use the data network for voice calls between offices. Advantages. Interoffice calls are free, since the company already has the bandwidth between offices. The technology is transparent to the user, and requires minimum training. The only new equipment required is a gateway at each office. Voice quality is good, because the company has control over the bandwidth. Disadvantage. Extra bandwidth may be required between offices, which offset the savings. Other factors... The carrier providing the interoffice bandwidth will almost certainly offer an alternative solution including management of the internal telephone traffic. IP PBX A traditional Private Branch Exchange (PBX) connects all the phones within an organization to the public telephone network. Essentially IP PBX replaces all the internal phones with VoIP telephones. The IP PBX has standard telephone trunk connections to the public telephone network. The IP PBX is a PBX with VoIP, but it also has the ability to support VoIP over the Internet and Office to Office VoIP. Advantages. Single cable infrastructure. The technology is transparent to the user, and requires minimum training. Future proof technology. Disadvantages. Primarily useful for Greenfield sites, but can be adapted to work with existing technology. . How VoIP works part 2 : The Protocols. I have made an assumption that both ends of a VoIP telephone conversation are compatible. This compatibility only happens if both ends agree to use the same protocol. All manufacturers who claim to be producing industry standard voice over IP either support SIP or H.323 protocol. So what is H.323 ? Over the next few years, the industry will address the bandwidth limitations by upgrading the Internet backbone to
49147559-VOICE-OVER-IP.docx