TCP/IP Transport

TCP/IP Transport

Port Numbers
1. For the client/server model to work, the server's computer process must start & open a TCP port, waiting on TCP segments to arrive into that TCP port
2. Port numbers for both TCP & UDP range from 0 through 65,535, because they exist in the headers as 16-bit binary numbers
3. To use a port to communicate, an application must ask TCP for permission to use that port with a process called opening a port
TCP and UDP Functions
1. The maximum allowed length of data link frame's data field defines the maximum size of an IP packet encapsulated in a data link frame
2. TCP provides a guaranteed delivery service to all applications that use TCP, whereas UDP does not
3. The size of the UDP data field is potentially limited to some maximum size on each link, based on that link's IP MTU
Error Recovery
1. When an error happens, the Recovery happens later
2. The TCP error recovery process uses the same SEQ & ACK fields that hosts use to confirm that TCP segments arrive
3. When the receiving host gets some of the TCP segments, but not all, the receiving host can send back an ACK- but with a value that tells the sender to recover some of the data
Upper Layers
1. Network layer IP forwarding logic, ignoring the lower layers, follows a hop by hop process between hosts & routers
2. The application protocol on the sending host adds an application protocol header, expecting that the receiving host's application layer protocol will read & react to the contents of that header
3. A TCP segment is the part of a message in the network that begins with the TCP header, through the encapsulated data, but ignoring the lower-layer headers & trailers

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	Created by pinedaluis8 over 11 years ago