Mis Final

Question 0

Backbone network components

Answer 0

Network cable - most common is optical fiber because of high data rates

Hardware devices- switches routers and gateways

Question 1

Backbone network

Answer 1

High speed networks linking an organizations LANs

Also called enterprise networks, or campus-wide networks

Question 2

Switch

Answer 2

Filters packets using data link layer

Connects two or more network segments
Can connect different cable types

Question 3

Router

Answer 3

Forwards packets using network layer addresses

Examines destination address of the network layer
Strips off data link packet
Only processes packets addressed to it

Question 4

Gateways

Answer 4

Routes packets using network layer addresses
Only process messages addressed to them
More complex than routers or switches
Can connect networks that use the same or different data link or network protocols

Question 5

Layer-3 switches

Answer 5

Similar to L2, but switch messages based on IP addresses( datalink)

Have best of switches and routers
Can support more simultaneously active ports than routers

Question 6

Three layers of backbone architectures

Answer 6

Access layer : used in LANs attached to BBs

Distribution layer : connects LANs together

Core layer : connects backbones together within the enterprise

Question 7

Switched backbones

Answer 7

Most common more cables but fewer devices
Improved performance and simple to manage
Used in distribution layer in new buildings. Can be rack or chassis based

Question 8

Routed backbones

Answer 8

Move packets along back bond on basis of network layer address
Core network
Uses BUS and Ethernet 100base-t

Also called subnetted backbones
Advantage is LAN segmentation
But it is timely and requires more management

Question 9

Virtual LANs

Answer 9

Assigns computers into LAN segments by software

Can be a single switch or a multiswitch VLAN

Very popular

Question 10

Rack mounted backbones

Answer 10

All switches in one "rack" room
Easy to upgrade and maintain 
Requires more cables
MDF OR CDF are other names for rack room
Main distribution facility or central """"

Question 11

Chassis based switched backbones

Answer 11

Enables admins to plug modules into switch

Advantage is flexibility

Question 12

VLAN

Virtual LANs

Answer 12

New type made possible by high speed switches (smart switches)
Fasted and more flexible
More complex and usually used on large networks

Single switch vlans
Multi switch vlans

Question 13

How VLANs work

Answer 13

Computer is assigned VLAN ID
Each ID is matched to IP subnet

Computers assigned to VLAN by physical port they are plugged into

Question 14

Multi-switch vlans

Answer 14

Use IEEE 802.1q - 16 byte VLAN tag is inserted into the 802.3 packet

VLAN tag is a header stripped off at destination Ethernet packet is sent inside dest. Computer

Question 15

VLAN advtg. Vs disadvtg

Answer 15

Faster performance
Traffic prioritization

Costly
Complex
Bleeding edge

Question 16

Best architectures for BBs

Answer 16

Switched backbone at distribution layer ( save cost. Increase perf.)

Routed backbones at core layer

Question 17

Ideal design for BB network

Answer 17

Mix layer 2 and 3 Ethernet switches in access layer

Mix 100base-t layer 2 switches with cat5e and cat 6 in distribution layer

Mix layer 3 switches running 10GbE or 40GbE over fiber

Question 18

Improving backbone performance

Answer 18

Upgrade devices
Change routing protocol

Upgrade or add additional circuit capacity

Reduce or restrict network demand

Question 19

Management implications of Bb networks

Answer 19

Traffic rate is always increasing

ATM is a legacy technology

Ethernet moving more into backbone - one standard used for LAN AND BB