[Original link] System Architect (Second Edition) Study Notes----Computer Network
Article directory
1. Basic concepts of computer networks
1.1 Development stage of computer network
- birth stage
- Formative stage
- interconnection stage
- Highly developed stage
1.2 Functions of computer networks
- data communication
- Resource Sharing
- Centralized management
- Implement distributed processing
- load balancing
1.3 Performance indicators of computer network
- rate
- bandwidth
- Throughput
- Delay
- Round trip time
- Utilization
1.4 Non-performance indicators of computer networks
- cost
- quality
- standardization
- reliability
- Scalability and upgradeability
- Ease of management and maintenance
2. Communication technology
2.1 Signal processing flow of transmitter
- Source encoding
- channel coding
- intertwined
- pulse forming
- modulation
2.2 Signal processing flow of receiver
- demodulation
- Sampling verdict
- deinterweave
- channel decoding
- source decoding
2.3 Characteristics of 5G communication network
- OFDM-based optimized waveforms and multiple access
- Implement scalable OFDM interval parameter configuration
- OFDM windowing improves multi-channel transmission efficiency
- Flexible frame design
- Massive MIMO (Multiple-Input Multiple-Output)
- millimeter wave
- spectrum sharing
- Advanced channel coding design
3. Network technology
3.1 Classification of networks
- Local Area Network (LAN)
- Mobile LAN (WLAN)
- Metropolitan Area Network (MAN)
- Wide Area Network (WAN)
- mobile communications
3.2 Common network topologies of LAN
- star structure
- Tree
- Bus structure
- ring structure
3.2 LAN networking technology – Ethernet technology
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Ethernet frame structure
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Minimum frame length: 64 bytes
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Maximum transmission distance: no strict limit
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Flow control: Prevents devices from losing frames in the event of congestion
3.3 WLAN standards
- IEEE 802.11: transmission rate 1-2Mb/s
- IEEE 802.11 b: transmission rate up to 11Mb/s
- IEEE 802.11 a: transmission rate up to 54Mb/s
- IEEE 802.11 g: The transmission rate can reach 54Mb/s, and it is also compatible with the 802.11 b standard
- IEEE 802.11 n: transmission rate up to 200Mb/s or more
3.4 WLAN topology
- Point-to-point
- HUB type
- Fully distributed
3.5 WAN technology
- Synchronous optical network
- digital data network
- frame relay
- Asynchronous transmission technology
3.6 Characteristics of WAN
- It mainly provides data communication-oriented services and supports users to use computers to exchange information over long distances.
- Wide coverage, long communication distance, wide area network has no fixed topology.
- The telecommunications department or company is responsible for the establishment, management and maintenance, and provides communication-oriented paid services to the whole society.
3.7 Classification of WAN
- public transmission network
- Dedicated transmission network
- wireless transmission network
3.8 Main Features of 5G Network
- service structure
- network slicing
3.9 System Architecture of 5G Network
4. Networking technology
4.1 Basic network equipment
- hub
- Repeater
- bridge
- switch
- router
- firewall
4.2 OSI model
- physical layer
- data link layer
- Network layer
- transport layer
- session layer
- presentation layer
- Application layer
4.3 Main features of TCP/IP
- Logical addressing
- Routing
- DNS
- error detection
- flow control
- Application support
4.4 TCP/IP protocol suite
- Internet Protocol IP
- Transmission Control Protocol TCP
- User Data Protocol UDP
- Virtual Terminal Protocol TELNET
- File Transfer Protocol FTP
- Email Transfer Protocol SMTP
- Network News Transfer Protocol NNTP
- Hypertext Transfer Protocol HTTP
4.5 TCP/IP network protocol model
- network interface layer
- Internet layer
- transport layer
- Application layer
4.6 Commonly used Internet services
- Domain name service DNS
- WWW service
- E-mail email service
- FTP file transfer service
- Telnet remote login service
- Gopher
4.7 Switch functions
- Hub function
- Relay function
- bridging function
- Isolate conflict domain function
4.8 Basic exchange principles
- Forwarding path learning
- Data forwarding
- Data flooding
- Link address update
4.9 Router functions
- heterogeneous network interconnection
- Subnet protocol conversion
- Data routing
- rate adaptation
- Isolate the network, prevent network storms, and implement firewalls
- Message fragmentation and reassembly
- Backup, flow control
4.10 Classification of routing protocols
- Interior Gateway Protocol IGP
- Exterior Gateway Protocol EGP
5. Network Engineering
5.1 Links of network engineering
- Network Planning
- web design
- network implementation