1
CHAPTER 13
Local Area Networks: Ethernet
Solutions to Odd-Numbered Review Questions and Exercises
Review Questions
1. The preamble is a 56-bit field that provides an alert and timing pulse. It is added to
the frame at the physical layer and is not formally part of the frame. SFD is a one-
byte field that serves as a flag.
3. A multicast address identifies a group of stations; a broadcast address identifies
all stations on the network. A unicast address identifies one of the addresses in a
group.
5. A layer-2 switch is an N-port bridge with additional sophistication that allows
faster handling of packets.
7. The rates are as follows:
9. The common Fast Ethernet implementations are 100Base-TX, 100Base-FX, and
100Base-T4.
11. The common Ten-Gigabit Ethernet implementations are 10GBase-S, 10GBase-L,
and 10GBase-E.
Exercises
13. The bytes are sent from left to right. However, the bits in each byte are sent from
the least significant (rightmost) to the most significant (leftmost). We have shown
the bits with spaces between bytes for readability, but we should remember that
that bits are sent without gaps. The arrow shows the direction of movement.
← 01011000 11010100 00111100 11010010 01111010 11110110
Standard Ethernet: 10 Mbps
Fast Ethernet: 100 Mbps
Gigabit Ethernet:
Ten-Gigabit Ethernet: 1 Gbps
10 Gbps
docsity.com
