Frame Relay (FR) is a fast packet switching technology based on fiber optic digital transmission and user equipment intelligence, simplifying the X.25 network node protocol function. Compared with X.25, FR is more suitable for data applications with higher rate and real-time requirements.
Characteristics of Frame Relay services
1. The Frame Relay data transmission protocol retains only the functions of the physical layer and the core sublayer of the data link layer. Data is forwarded across the network in link layer format.
2, Frame Relay users have flexible access rates.
3, frame relay using statistical multiplexing technology, allowing users to take up other free bandwidth to enjoy higher than the promised rate of service, not only to make full use of the physical medium of the transmission bandwidth, a good response to the burst of data, but also can greatly simplify the network topology, reduce hardware costs.
Application of Frame Relay service:
1, LAN interconnection: frame relay in the successful application of LAN interconnection, mainly because of the frame relay statistical multiplexing technology is particularly suitable for the transmission of large amounts of burst data for the LAN.
2, to provide multimedia services: frame relay low latency, high throughput characteristics, suitable for videoconferencing, telemedicine, distance learning and other real-time multimedia applications.
(2) ATM service
Telecommunications network is divided into transmission, multiplexing, switching, terminals and other parts, which, in addition to terminals, transmission, multiplexing and switching of the three parts of the three parts together collectively referred to as the transfer mode (also known as the transfer mode) ATM is an asynchronous transfer mode of the acronym in English, ATM synthesizes the advantages of the circuit-switching and packet-switching, which is able to flexibly allocate bandwidth, and the elimination of the complex flow control and error correction. Complex flow control and error control, so that the transmission delay is greatly reduced. It can be used to interconnect LANs and provide real-time multimedia services with QOS guarantee.
Features of ATM
1. ATM is a connection-oriented communication method. The so-called connection-oriented, that is, before the communication between the receiving and transmitting terminals to establish a connection, in the communication, the message or information is constantly transmitted on the connection, so in a communication with more than one message or information, from the transmitting end to the receiving end of the route is fixed.
2. ATM is a packet switching method with fixed packet length. Traditional packet switching is not fixed in the way, ATM is the letter element switching.
3. ATM has the ability of statistical multiplexing.
4, ATM can synthesize a variety of services.SDH (SynchronosDigitalHierarchy) is a new digital transmission system. It will be called a revolution in telecommunication transmission system.
X.25 is a packet-switching technology that reliably transmits data over a packet-switched network. The X.25 network can be accessed through a direct connection, or through an asynchronous connection dialed into a packet assembler/disassembler. Servers running Routing and Remote Access only support direct connections to the X.25 network using an X.25 smart card.