Switching Network

1.Switching Network

1. Circuit Switchnig Networks (ex. Telephone Network)
• FDM
• TDM
• CDM
• WDM
2. Packet Switching Networks
• Virtual Circuit Switching
• connection-oriented Service
• Header in packet includes VCI(Virtual Circuit Identifier)
• Switch should maintain the circuit state information
• Datagram Method
• Each packet sent independently
• Use Routing Table in Router
• Typically IP(Internet Protocol)

Statistical TDM

• 회선 교환방식에서의 TDM의 단점을 극복.
• 데이터를 전송하고자 하는 채널에 대해서만 슬롯을 유동적으로 배정한다.  즉, 사용자들의 필요에 따라 슬롯을 할당.
• #Delay and Loss in Packet Switching Network# 
3. Message Switching Networks
• Use store & forward
• Special case of the Packet switching network
• Performance Evaluation
• <Pors>
1. Overhead in header reduced
2. Inordered packet
• <Cons>
1. Store and forward Method spends much times than Packet Switching Networks 
2. Retransmittion wastes bandwidth

참고 : 컴퓨터 네트워크  by 김성철교수