Packet Switching In Computer Networking
PACKET SWITCHING : Packet Switching is a digital networking communication method that groups all transmitted data, regardless of content, type or structure in a suitably sized block called "Packet".
Packet switching features delivery of variable bit rate data stream over a shared network, when traversing network adapters, switches, routers etc.
Packets are buffered and queued, resulting in variable delay and throughput depending on the traffic load in the N/W .
Best example of packet switching is Internet and LAN.
Division of Packet Switching
Circuit Switching Packet Switching Message Switching
Packet Switching
ConnectionLess Connection Oriented
(datagram) (virtual circuit)
ConnnectionLess Packet Switching :
All packets have header including all address information as source address, destination address and port number.
Each packet treated independently.
Connection less protocol are => Ethernet, Ip & Udp
Connection Oriented Packet Switching :
A connection is defined and preallocate in each involve node during a connection phase before any packet is transferred.
All packet include connection ID rather than address info.
Connection Oriented protocols are => x.25, frame-relay
X.25 :
It is a reliable protocol based on node to node automatic repeat request.
It is a network layer protocol.
Frame Relay :
Non reliable protocol
It is a further development of x.25, fast & more cost effective.
It is a data link layer protocol.
It does not provide logical address & routing , it is only used for semi-permanent connections.
