Anna University Coimbatore 2009 B.E Electronics

following:
· Logical addressing.
· Routing.
8. What is a virtual circuit?
A logical circuit made ranging from the sending and receiving computers. The
connection is made after both computers do handshaking. After the connection, all
packets follow the identical route and arrive in sequence.
9. elaborate data grams?
In datagram approach, every packet is treated independently from all others. Even
when 1 packet represents just a place of a multipacket transmission, the network treats
it although it existed alone. Packets in this technology are referred to as datagram.
10. elaborate the 2 kinds of implementation formats in virtual circuits?
Virtual circuit transmission is implemented in two formats.
DSAP SSAP Control info
· Switched virtual circuit
· Permanent virtual circuit.
11. What is meant by switched virtual circuit?
Switched virtual circuit format is comparable conceptually to dial-up line in
circuit switching. In this method, a virtual circuit is created whenever it is needed and
exits only for the duration of specific exchange.
12. What is meant by Permanent virtual circuit?
Permanent virtual circuits are comparable to leased lines in circuit switching.
In this method, the identical virtual circuit is given ranging from 2 uses on a continuous
basis. The circuit is dedicated to the specific uses.
13. describe Routers.
Routers relay packets among multiple interconnected networks. They Route
packets from 1 network to any of a number of potential destination networks on
Internet routers operate in the physical, data link and network layer of OSI model.
14. What is meant by hop count?
The pathway requiring the smallest number of relays, it is called hop-count
routing, in which every link is considered to be of equal length and provided the value one.
15. How can the routing be classified?
The routing can be classified as,
· Adaptive routing
· Non-adaptive routing.
16. What is time-to-live or packet lifetime?
As the time-to-live field is generated, every packet is marked with a lifetime,
usually the number of hops that are allowed before a packet is considered lost and
accordingly, destroyed. The time-to-live determines the lifetime of a packet.
17. What is meant by brouter?
A brouter is a single protocol or multiprotocol router that sometimes act as a
router and sometimes act as a bridge.
18. Write the keys for understanding the distance vector routing.

Earning:   Approval pending.