0SI layer-7 protocol: Transmission Layer Analysis

0SI layer-7 protocol: Transmission Layer Analysis
The lower layer of 0SI is mainly for data communication, the higher layer of 0SI is for users and information processing. The transport layer is located between the lower and higher layers. It is an interface layer connecting the upper and lower layers. It plays an active and standby role and can make up for and strengthen the services provided by the network layer.
1. the transport layer service provides virtual circuit services to the supplemental network layer at the network layer. The transport layer can ensure correct receipt of packets, and the transport layer protocol and Communication Subnet can form a reliable computer network. The network layer provides the datagram service. The Transport Layer Protocol must include error detection and error recovery. Www.2cto.com 2. The role of the transport layer transmits packets transparently from end to end through the network to provide reliable end-to-end communication. It provides transmission connections and provides network-independent transmission services to the Session Layer. End-to-End: equivalent transmission entity, from process to process. The Transport Layer shields high-level users from the details of the following communication subnets. 1) connection-oriented transmission services: reliable connection-free services: Unreliable 2) transmission service levels www.2cto.com can be subdivided into four categories: reliable connection-oriented protocols; unreliable connection-free protocols; voice transmission protocols requiring sequential and scheduled transmission; fast and highly reliable real-time protocols. 3) data transmission 4) User Interface 5) Connection Management 6) security and confidentiality 3. Service Quality QOS: the characteristics of some transmission connections seen between two transmission nodes, it is a measure of the performance of the transport layer, reflecting the transmission quality and service availability. Parameters can be used to describe.