SWITCHING

Some short questions about switching :

Q.1) Circuit Switching is used for 
           Physical layer

Q.2) A -------- n/w is made of a set of switches connected by physical link in which each link is devided into n channel.

==> Circuit Switched

Q.3) Simplest type of switching fabric is :
==> crossbar switch

Q.4) A ------ switch is a multistage switch with micro switches at each stage that route the packet based on the output port represented as a binary string
==> banyan 

Q.5)which address in the header part of a packet in a datagram n/w normally remain same during the entire journey of the packet?
==> destination address

Q.6) A switch in a datagram n/w uses a routing table that is based on  -------  ?
==>  destination address

Q.7) The network layer in the internet  is designed as a -----?
==>   datagram n/w

Q.8) In a ------- n/w two types of addressing are involved global and local ?
==>    virtual circuit n/w

Q.9) A switched wan is normally implemented as  a ------- n/w ?
==>  virtual circuit

Q.10) ARP is ---- ?
==>  Address Resolution Protocol
A tcp/ip protocol used to dynamically bind a high level ip address to a low level physical hardware address.

Q.11) Which of the following tcp/ip protocol is used for file transfer with minimal capability & minimal overhead ?
==>  TFTP

Q.12)  Ip address can be used to specify a broadcast & map to hardware broadcast if available, by conversion broadcast address has hosted with all bits ?
==>   1

Q.13)   How many class A,B & c networks ID's can exist ?
==> 2,113,658
    

 
     

Packet Switching In Computer Networking

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.