1. How far apart can the fathest station be in an Ethernet 10Base-T
network with a single
hub? With multiple hubs? Can you have loops in an Ethernet
10Base-T network with
multiple hubs?
Multiple Hubs in Ethernet 10Base-T à»ç¹¡ÒÃàª×èÍÁ
Hubs ËÅÒµÑǾÃéÍÁ¡Ñ¹â´ÂãªéÃкº¡ÒÃÊè§áºº
10Base-T ·ÓãËéÁÕÃÐÂСÒÃ
Êè§ÊÙ§ÊØ´ 500 àÁµÃ
áµè¡ÒõèÍàª×èÍÁäÁèÊÒÁÒöµèÍà»ç¹
Loop à¾ÃÒШзÓãËé¡ÒÃÊè§äÁèÊÔé¹ÊØ´
2. How far apart can farthest station de in
an Ethernet 100Base-TX network with asingle
hub? With multiple hubs?
Multiple Hubs in Ethernet 100Base-TX à»ç¹¡ÒÃàª×èÍÁ
Hubs ËÅÒµÑÇâ´ÂãªéÃкº¡ÒÃÊè§
100Base-TX ·ÕèÁÕ¤ÇÒÁàÃçÇ㹡ÒÃÊè§
100 Mbps áµèà¾×èÍÃÑ¡ÉÒ¤ÇÒÁàÃçǨ֧ÁÕÃÐÂзҧ¨Ó¡Ñ´ÃÐËÇèÒ§
Hubs áÅÐ Station »ÃÐÁÒ³
200 àÁµÃ
3. What is a shared media network? Why do you inevitably have conggestion
in a shared
media network as the number of station grows? Is Ethernet 10Base-T
a shared media
network? Ethernet 100Base-tx?
Shared media network à»ç¹ÃٻẺ¢Í§¡ÒèѴ¡ÒâéÍÁÙÅà¾×èÍ»éͧ¡Ñ¹¡ÒÃÍÑ´á¹è¹¢Í§¢ÑÍÁÙÅ
â´Â Hubs
¨Ð·Ó¡ÒÃÃѺ¢éÍÁÙŨҡ·ÕÅÐ
Station àÁ×èÍÃѺÁÒáÅéÇ¡ç¨Ð¡ÃШÒÂÍÍ¡ä»ãËé
Station Í×è¹æ áÅéǨ֧ÃѺ¢éÍÁÙÅãËÁè¨Ò¡
Station ÍÖè¹·ÕèãËéÃÍÍÂÙè
4. Are switched network shared media network? What dose this imply for
congertion as a
smitched network grow?
Swiched à»ç¹µÑÇÊ觢éÍÁÙÅ·ÕèãªéÃкº¡ÒÃÊ觢éÍÁÙŨҡ¼ÙéÊè§ä»Âѧ¼ÙéÃѺä´éâ´ÂµÃ§
â´ÂáµèÅÐ Station ¨ÐµéͧÁÕ
Address à¾×èÍãªé㹡ÒÃ
Êè§áÅÐÃѺ¢éÍÁÙÅ
àªè¹ Ãкºâ·ÃÈѾ·ì
5. Why do we say that switched operate at layer 2? How do
Ethernet switched restrict
traffic to a single path between station? How do ATM network do this? Distinguish
be-
tween permanent and switched virtual circuits. Is virtual circuits
operation connection
-oriented or connectionless?
Single path ¡ÒÃÊ觢éÍÁÙÅâ´ÂÁÕªèͧ·Ò§¡ÒÃÊ觪èͧ·Ò§à´ÕÂÇ
ÁÕ¡ÒÃÃкطÕèÍÂÙè¼ÙéÃѺ»ÅÒ·ҧ·ÓãËéÊè§ä»»ÅÒ·ҧä´é·Ñ¹·Õ
ATM network ¡ÒÃÊ觢éÍÁÙÅ·ÕèÊÒÁÒöàÅ×Í¡ªèͧ·Ò§¡ÒÃÊè§ä´é
Permanent virtual circuits à»ç¹ªèͧ·Ò§¡ÒÃÊ觶ÒÇö١ãªé·Ø¡æ
¤ÃÑé§àÁ×èÍÁÕ¡ÒÃÊ觢éÍÁÙÅ
Switched virtual circuits à»ç¹ªèͧ·Ò§¡ÒêÑèǤÃÒÇà»ÅÕè¹àÊéÒ·Ò§ä´éàÃÕèÍÂæ
6. What are the advantrages of Ethernet switched compared to ATM switched?
What are
the advantrages of ATM switched compared to Ethernet switched?
µÍº
Ethernet switched à»ç¹ switched ·Õèàª×èÍÁµè͡ѺÍØ»¡Ã³ìËÅÒÂÍÂèÒ§·ÕèãªéÃѺ-Êè§ÊÑÒ³¢éÍÁÙÅ
ATM switched à»ç¹ switched ·Õèàª×èÍÁ¡Ñ¹ËÅÒÂæ
Íѹà¾×èÍà»ç¹ªèͧ·Ò§ã¹¡ÒÃÊ觢éÍÁÙÅ
7. What is a virtual LAN(VLAN)? What are the two reasons why organization
use virtual
LANs? What is the disadvantage of virtual LANs?
µÍº
Virtual LANs à»ç¹Ãкº Lan
·Õèà»ç¹ÀÒ¾àÊÁ×͹
ÁÕ switched à»ç¹µÑǤǺ¤ØÁ¡ÒÃà»Ô´»Ô´
·ÓãËéÊÒÁÒöÃкØÇèҨСÃÃШÒ¢éÍÁÙÅãËé
ã¤ÃºéÒ§ ·ÓãËéÁÕ¤ÇÒ
ÁàÃçÇ㹡ÒÃÊè§ÊÙ§
8. What is alternative routing? What is the other cheracteristic of layer
3 operation? What
are the advantages of alternative routing?What type of device gives alternative
routing?
Given the advantages of alternative routing, why are router not used everywhere?
µÍº
Alternative routing à»ç¹Ãкº·ÕèÊÒÁÒö¡Ó˹´·Ò§àÅ×Í¡ä´é¡ÇèÒ
1 ·Ò§àÅ×Í¡
9. Distinguish between layer 1and layer 2operation.Distinguish between
layer 2 and layer
3 operation. What type of connector box operates at layer 1? At layer
2? At layer 3?
How do layer 3 switched, flow routers, and ASIC router give some
of the advantages
of both layer 2 and layer 3 operation?
Layer 1 à»ç¹¡ÒÃÊ觢éÍÁÙÅâ´Âãªé
Hubs Êè§ 1 ºÔµ/µèÍ
1 ªèǧàÇÅÒ
Layer 2 à»ç¹¡ÒÃÊ觢éÍÁÙÅâ´Âãªé
Switched Êè§à»ç¹á¿ÃÁâ´ÂµéͧÃкطÕèÍÂÙè
Layer 3 à»ç¹¡ÒÃÊ觢éÍÁÙÅâ´Âãªé
Router àÅ×Í¡àÊé¹·Ò§·Õè´Õ·ÕèÊش㹡ÒÃÊ觢éÍÁÙÅ
àÃÕ§ÅӴѺµÒÁ
Address
10.What are layer 3 switched?
Layer 3 switched à»ç¹ switched
·ÕèàÅ×Í¡ãªéàÊé¹·Ò§ä´éÁÒ¡¡ÇèÒ
1 àÊé¹·Ò§
11.What is a carrier?
Carrier à»ç¹µÑǹӷÕèãªé㹡ÒÃÊ觢éÍÁÙŨҡÍÕ¡·Õè˹Öè§ä»ÂѧÍÕ¡·Õè˹Öè§
12.What is a leased line? Why do organization use leased lines? What
are the disadvan-
tages of network made from leased lines?
Leased line ¤×Í ÊÒÂàªèÒ
à¾×èÍàª×èÍÁµèÍ
Site network ¨Ò¡·Õè˹Öè§ä»ÍÕ¡·Õè˹Öè§â´ÂµÃ§
13.Why is a public switched data network (PSDN) represented as a
cloud? How many
leased lines dose a site have using a public switched data network?
How many lease
lines dose a site have using a network of leased lines?
Public switched data network (PSDN)à»ç¹Ãкº·Õè¹Ó
Leased line ¢Í§áµèÅÐ Site
ÁÒµèÍàª×èÍÁà¢éÒ´éÇ¡ѹ·ÓãËé»ÃÐËÂÑ´
Leased line à¾ÃÒÐ 1 site ãªé
1 leased line àªè¹ Ãкºâ·ÃÈѾ·ì
14.Distinguish between circuit switching and packet switching in
terms of guarantee of
transmission capacity and cost.Why is packet switching less expensive than
circuit ?
Circuit switching à»ç¹¡ÒÃÊ觢éÍÁÙÅ·Ò§ã¤Ã·Ò§Áѹ
â´Â¢éÍÁÙŢͧáµèÅÐ
Station
¨ÐÁÕªèͧ·Ò§¡ÒÃÊ觢ͧµÑÇàͧ੾ÒÐ
Packet switching à»ç¹¡ÒÃÊ觢éÍÁÙÅ·Õèãªéªèͧ·Ò§à´ÕÂǡѹ
â´Â¢éÍÁÙÅ·ÕèÊ觢ͧáµèÅÐ
Station ¨ÐÊè§à»ç¹ Packet
15.Distinguish between dediccate and dial-up switched data network.When
would you
use each?
Dedicated connections à»ç¹Ãкº·ÕèÁÕ¡ÒÃÒª×èÍÁµèͧ͢ÊÒÂÊÑÒ³µÅÍ´àÇÅÒ
Dial-up service à»ç¹Ãкº·Õè¨Ðàª×èÍÁµèÍàÁ×èÍÁÕ¡ÒÃÊè§
Address àªè¹ Ãкºâ·ÃÈѾ·ì
16.All commercial public packet switched services offer permanant virtual
circuits.How
dose this make their services competitive with meshes of leased lines?
Permanant virtual circuits à»ç¹Ç§¨ÃàÊÁ×͹¨ÃÔ§·ÕèÊÁÁصԢÖé¹ã¹à¤ÃÕÍ¢èÒÂ
17.Which public switched data network are circuit switched? Packet
switched? Which
public switched data network use dedicated lines? Which use dial-up lines?
Packet switched »ÃÐËÂÑ´¡ÇèÒ¡ÒÃãªé
Circuit switched
Dedicated lines àª×ÍÁµè͵ÅÍ´àÇÅÒ·ÓãËéãªé§Ò¹ä´é·Ñ¹·ÕäÁèµéͧÁÕ
Address
18.What is the most popular public switched data network service? Why is
it the most
popular?
Frame delay à¾ÃÒÐãªéÃкº¡ÒÃÊ觢éÍÁÙÅẺ
Packet switched áÅСÒÃàª×èÍÁµèÍÊÑҳẺ
Dedicated lines ·ÓãËé¡ÒÃÊè§
¢éÍÁÙÅ·Óä´é§èÒÂ
»ÃÐËÂÑ´ áÅÐÁÕ¤ÇÒÁàÃçÇ㹡ÒÃÊ觷ÕèàËÁÒÐÊÁ
19.Compare ISDN,Frame Relay, and ATM in terms of scalability.
ISDN -µèÍÍØ»¡Ã³ìä´éËÅÒÂÍÂèÒ§
-µÔ´µèÍâ´Âãªé
Address
-Ê觢éÍÁÙÅẺ
Circuit switched
Frame Relay -Ê觢éÍÁÙÅẺ
Packet switched
-àª×èÍÁµè͵ÅÍ´àÇÅÒ
ATM - ÁÕÅѡɳÐàËÁ×͹
Frame Relay áµèÁÕ¤ÇÒÁàÃçǹéÍ¡ÇèÒáÅÐãªéµé¹·Ø¹á¾§¡ÇèÒ