Anna University Coimbatore 2009 B.E Electronics

in the data so that the receiver doesn' t mistake the data for a flag.
35. describe LAN.
A Local Area Network (LAN) is a data communication system that allows a
number of independent devices to communicate directly with every other in a limited
geographic area.
36. Mention the different architecture in a LAN.
LAN is dominated by four architectures.
a) Ethernet
b) Token bus
c) Token ring
d) Fiber distributed data interface (FDDI)
37. describe a standard 802.3
IEEE 802.3 supports a LAN standard originally developed by Xerox and later
extended by a joint venture ranging from digital equipment corporations. Intel Corporation
and Xerox. This was called 'Ethernet' .
38. List the most command types of Base band 802.3 LAN.
a) 10 Base 5
b) 10 Base 2
c) 10 Base T
d) one Base 5
e) 100 Base T
39. Mention the various types of Ethernet networks.
a) Switched Ethernet
b) Fast Ethernet
c) Gigabit Ethernet
40. Write short notes on FDDI.
Fiber distributed data interface is a local areas. Network protocol standardized by
ANSI and ITU-7. It supports data rates of 100 Mbps and provides a high-speed
option to Ethernet and token ring access method used here is token passing.
41. define the 3 HDLC station types?
The 3 HDLC station kinds are:
Primary station: The primary station has the complete control of the link. The
Primary station sends commands to the secondary station.
Secondary station: The secondary station sends responses.
Combined station: The combined station is one, which acts either as a primary or a
Secondary, depending upon the nature and direction of the transmission.
Combined station sends both commands and responses.
42. What is piggy backing?
Piggybacking means combining data to sent and acknowledgement of the frame
received in 1 single frame.
Piggy backing can save bandwidth because the overhead from a data frame and an
ACK frame can be combined into just 1 frame
43. Name the 4 kinds of S-frames?
The 4 kinds of S-frames are
Receive ready (RR). The value of the code sub field is 00
Receive not ready (RNR). The value of the code sub field is 10
Reject (REJ). The value of the code sub field is 01
Selective reject (SREJ). The value of the code sub field is 11
44. Name the 5 categories of U-frames?
The 5 categories of U-frames are ?Mode setting ?Unnumbered exchange ?Disconnection. ?Initialization mode. ?Miscellaneous mode

Earning:   Approval pending.