1. LAN is divided into wired medium LAN and wireless medium according to the type of transmission medium.
LAN The early computer network was mainly wide area network, divided into Main computers and terminals (responsible for data processing) and communication processing equipment and communication circuits (responsible for data communication processing).
2. The computer network is logically divided into resource subnets and communication subnets
Resource subnets (computer systems, terminals, external network equipment and software information Resources; Responsible for the data processing business of the entire network, providing network resources and services.
Communication subnet (communication processing control machine - i.e. network nodes, communication lines and other communication equipment): responsible for network data transmission, forwarding and other communications Handle task network access (LAN, wireless LAN, wireless metropolitan area network, telephone switching network, cable TV network).
3. The core device of the switching LAN is the LAN switch
Metropolitan area network concept: Network operators provide various information services within the city, using the broadband optical transmission network as an open platform and the promotion of dense wavelength division multiplexing technology based on the TCPIP protocol, resulting in the expansion of the bandwidth of the WAN backbone line.
The metropolitan area network is divided into core switching layer (high-speed data exchange), edge aggregation layer (routing and traffic aggregation), and user access layer (user access and local traffic control).
4. Advantages of hierarchical structureClear layer positioning, open interfaces, standard specifications, easy to set up and manage.
5. Basic functions of the core layer
(Design focus: reliability, scalability, openness) Connect to the aggregation layer, provide high-speed packet forwarding, and provide a high-speed secure QoS guaranteed transmission environment; realize backbone network interconnection and provide urban broadband IP data Exit; provides routing services required for users to access the INTERNET.
6. Basic functions of the aggregation layer
Aggregation of access layer user traffic, aggregation of data packet transmission, forwarding and Switching; local route filtering, traffic balancing, QoS priority management, security control, IP address translation, traffic shaping; forwarding traffic to the core layer or local routing for processing.
7. Establish and operate a broadband metropolitan area network Principles: operability, manageability, profitability, scalability.
Key technologies for management and operation of broadband metropolitan area networks: bandwidth management, quality of service QoS, network management, user management, Multi-service access, statistics and billing, IP address allocation and address translation, network security.
The broadband metropolitan area network must comply with carrier-level operation requirements (consider equipment redundancy, line redundancy) in the construction plan and rapid diagnosis and self-recovery of system faults).
Quality of service QoS technology: resource reservation [SD2], differentiated services [SD3], multi-protocol label conversion [SD4].
Management There are three basic solutions for bandwidth metropolitan area networks: in-band network management, out-of-band network management [SD5], and both in-band and out-of-band network management are used.
The above is the detailed content of Computer Level 3 Network Technology Knowledge Points. For more information, please follow other related articles on the PHP Chinese website!