Computer network knowledge

1. Computer Network Protocol

TCP/IP: reliability and scalability

Layer-4 structure:

Application Layer: communication between applications, including all high-level protocols such as HTTP, FTP, telnet, SMTP, SNMP, and DNS

Transmission Layer: Data Transmission

Network Interconnection layer: Logical Address to physical address (ARP Protocol)

Network Interface Layer: encapsulation and unblocking between the IP datagram and the frame format of the physical network

UDP: connectionless transmission protocol

Netbeui: Non-Routing Protocol of IBM

IPX/SPX: 32-bit network address

2. Network Management

Network management includes network device management, server management, user management, and resource management.

Network Management in ISO: configuration management, fault management, performance management, security management, billing management, Desktop Management

3. Network Exchange Technology

Circuit Switching, packet switching, group switching, IP phones, ATM technology, and Softswitch

Port switching, frame switching, and cell switching

4. Network Storage Technology

Directly attach storage Das

Storage Area Network SAN (FC TCP/IP Protocol)

Network attached storage NAS

IP Storage lan isci (TCP/IP Protocol)

5. Network Access Technology

ADSL, LAN access, dial-up access, DSL access, optical fiber access (fttb, FTTC, FTTH), cable modem, ddnleased line, 802.11, GPRS, 3G

6. Integrated Wiring Project

Architecture subsystem, workspace subsystem, management subsystem, horizontal subsystem, vertical trunk subsystem, and equipment Subsystem

Four grounding methods for data centers:

AC work grounding: the AC Power grounding wire is connected with the grounding points of all AC equipment.

DC working grounding: the zero potential of the power supply is connected together with the ground network

Safety Work grounding: All devices are grounded

Lightning Protection and grounding: