Communications

Voice Over IP
We developed an H.323 protocol stack which successfully interoperated with other H.323 implementations, including Microsoft NetMeeting

Many useful applications of computers require that they communicate with other devices. Serial, parallel, USB, and firewire are all protocols designed to connect computers to devices such as mice and printers.

The internet and all of the things it has enabled are driven by the ability of one computer to communicate with another, which is more specialized. There are a number of different communication protocols that computers use for this, and there are a number of different levels at which these protocols exist. This layering of protocols is called the protocol stack.

The protocol stack can be pieced together in different ways using different protocols. A common stack is built on Ethernet. Ethernet allows a computer to send a message to another computer on the same network. IP runs on top of Ethernet, and relieves the computer of having to be referred to by its MAC address, which is hardwired. TCP adds to IP the ability to ensure that packets arrive in order without data loss or corruption. Many, many different protocols can be run on top of TCP to enable all kinds of data to be sent over the internet.

A different stack could use a token ring in place of Ethernet or UDP in place of TCP. Some higher level protocols use multiple stack simultaneously. H.323, for example, uses TCP to set up a voice call, but uses UDP to actually carry the voice data. Since TCP is more reliable and UDP is faster, this combines the best of both protocols to achieve voice communication.

STI has designed communications systems ranging all the way from low level drivers, such as serial communications drivers, to high level protocols, such as H.323. If you need a computer to communicate with something, we’ll be glad to help you, so please contact us today!