文档介绍：IT系统架构基础知识
IT系统的基本体系结构
应用服务器
应用程序
操作系统
硬件
数据库
TCP/IP
基于应用服务器的三层/多层架构是迄今为止比较合理的，构建大规模、高性能、高可靠性、高扩展性的IT系统的唯一比较成熟Topology (Logical)
Topology (Physical)
Access Method
MultiStation Access Unit
Cat 3/5
Cable Types
100m
Max. Segment
FDDI Ring 接口卡
FDDI Ring
100 Mbps
Ring
Token
Dual Ring Star
Data Rate
Topology (Logical)
Access Method
Topology (Physical)
Concentrator
Single Attachment Stations
Dual Attachment Station
Dual Attachment Station
Fiber
Cable Type
2000m
Max. Segment
中继器
Repeater
Repeaters
Repeaters repeat a signal from one port to another.
Repeaters pass all traffic through without error checking or filtering..
Repeaters pass collisions, too.
Repeaters are used primarily to overcome maximum segment length restrictions.
telnet
Repeaters extend the maximum allowed distance between nodes.
集线器
Hub
Hubs...
Hubs propagate a signal received on one port to all other ports..
Hubs propagate errors and collisions across ports, too.
Hubs simplify the addition and removal of nodes on a LAN.
Hubs are also used to connect network segments cabled with different media types.
telnet
Hubs make it very easy to add and remove hosts on a network.
网桥
Bridge
Hub
Bridges
Bridges provide all the functionality of a hub, PLUS ...
Bridges filter frames by destination MAC, and segment a LAN into multiple collision domains.
Bridges filter signal and timing errors.
Bridges can be used to connect segments operating at different speeds.
telnet
telnet
Hub
Bridges make it possible to segment your network into separate collision domains to minimize collisions and improve performance.
Separate Collision Domains
交换机
Switches
Switches provide all the functionality of a bridge PLUS ...
Switches typically offer more ports than bridges.
Switches allow for multiple, parallel channels of communication between ports.
Switches sometimes offer “full-duplex” functionality.
Switches are replacing both bridges and