AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Syn ack synack11/6/2022 Destination port: It is the port used by the server for the communication.Source port: It is the port used by client to sent the packet.Options (if Data Offset > 5,padded at end with “0” bytes if necessary) The rate of data transmission between two devices is managed by a windowing system to prevent a fast sender from transmitting more data than can be supported by the receiving. Syn ack synack windows#One other interesting feature of TCP is the windows handling. This means the recipient might get the packet in the wrong order, the sequence number make sure when reassembling, packets are in the correct order. Packets may use different paths to reach the recipient, or a corrupted packet need to be resend. There is also a sequence number to assemble the packets in the original order. To do so, the TCP emebed in its header a checksum verifying the data is not corrupted. TCP is a protocol that makes sure the data has been well delivered, in the correct order. This means it first establishes an end-to-end communication session before any data may be send. In effect, they are used as temporary ports primarily by clients when communicating with servers. 49152 – 65535 are dynamic ports that are not officially designated for any specific service, and can be used for any purpose.1024 – 49151 are the registered ports used for IANA-registered services.0 – 1023 are used for common, well-known services.The Internet Assigned Numbers Authority has divided port numbers into three ranges. There are 2^16 different ports available (since the field for the port in the packet is 16 bits). Applications that communicate on IP networks are bound to one (or more) port(s) to send and receive data. HTTP, FTP and SSH are protocol from the application layer). For instance, the default port to access a web server to communicate with the protocol HTTP is the port number 80, the protocol FTP uses the port number 21 and the protocol SSH uses the port number 22. The two main transport protocols are TCP and UDP.Ī connection between two devices on the transport layer (with TCP or UDP) is done from port to port: Each network device using the protocol TCP or UDP has different “gates” where a communication can “go in or out”. The transport layer provides convenient services such as connection-oriented data stream support, reliability, flow control, and multiplexing. While the data link layer carries the point-to-point connections and the network layer carries the routing of packets, the transport provides end-to-end communication services for applications. Now I’ll talk about the layer 4: transport. I already wrote an article describing the OSI model and its 3 first layers ( physical, data link and network).
0 Comments
Read More
Leave a Reply. |