CertiGuide to Network+  9  Chapter 0100:  Network Protocols

Pop Quiz 0100.00 1 2 VIII  Routing Protocols

IP (Internet Protocol)

Coming from the military need to keep communications up even if some network traffic lines were down, IP (Internet Protocol) is the transport of the TCP/IP suite. IP is a connectionless protocol.

As with all connectionless protocols, this means less computer overhead than a connection-oriented protocol. Each device has or gets a unique logical address number for identification. A critical portion of the IP address is the subnet mask. You will see more about subnet masks shortly.

TCP is a connection-oriented delivery service that is found at the OSI Model’s Transport Layer. Being connection-oriented, it enables reliable data delivery by creating an end-to-end connection between the systems requiring data exchange.

This means the system creates a virtual network between the routers and computers. Once the circuit is complete, IP is used as the actual transport.

TCP is in the OSI Model’s Transport layer (layer 4). It and all other protocols in the TCP/IP stack are routable protocols.

UDP is a connectionless protocol, which like TCP, resides at the Transport Layer runs over the base IP protocol. Since it is connectionless, it is faster and requires less overhead than its sibling, TCP. UDP takes advantage of the address and port structure that already exists. No error correction or acknowledgement is provided, and no time is spent setting up such a service.

When would an application choose to send its data via UDP instead of TCP? Generally, when it has time-sensitive data to deliver. One example would be an Internet radio station. As with traditional “broadcast” radio, Internet radio is transmitted in real-time. In order to maintain timely delivery, Internet radio applications prefer to drop a second or two of audio if it is not received in a timely fashion, and resume playing the current audio, instead of going back to request the missed seconds of voice chatter.

Pop Quiz 0100.00 1 2 VIII  Routing Protocols