Mod 6

Question 1

1. Responsible4 communi bet end devices network interface cards, this allows upper layer protocols to access physical layer n error detection
2. Whatr iys 2sub layers in 802 LAN/MAN ?

Answer 1

1. DATA link LAYER
2. Llc( Logical Link Control) communi network sodt at UPPER n Device at Lower layers

MAC (media access control) // for data n media access control

Question 2

1. 4 basic layer 2 functions FRAD
2. Data link layers r defined by engineering orga 4?

Answer 2

1.accepts frame
2. De encapsulates
3. Re encapsulates
4.. Forwards new frame

2. IEEE( INSTI FOR EKEC N ELECTRONIC ENGINEER)
3. ITU / Insternational Telecommuni Union
   2.2 ISO * interna organi for Standards
   2.3 ANSI * American National Standards Institute

Question 3

1. This is arrangement n relationship of network dev n interconnection between them
2. Shows PHYSICAL CONNEC n how devices r interconnected
3. Iden. Virtual connec betw devices using dev interface n ip addressing schem

Answer 3

1. Topology
2. Physical topology
   3logical topo

Question 4

Physical topo has 3 WAN TOPO

Answer 4

1. Point 2 point // simplest n common wan topo, has 2 endpoints, nodes may not share media w other host since sipmle design
2. Hub n spoke// similar sa star topo where acentral site inter thru point 2 ooint LINKS
3. mesh // has high availa but

Question 5

End devicers on LAN r interconnect using —- topology, this is scalable n easy 2 trouble shoot

2. in d early ether n legacy token, —— all end sys chAINED TOGETHER N TERMINATED EAch end
3. ?? Each end sys is connected to anneighbor to FORM RING

Answer 5

1. Starr Topology / extendted sytar
2. Bus
3. RING

Question 6

DUPLEx
1. Half-duplex is?
2. Full duplex is?

Topologies Access Control Methods 2?

Answer 6

1. Half dup is 11dev to send N receive at a time on a shared medium, USES WLAN N BUS TOBOOLOGIES
2. Full dupl// trans,its simultaneous n receive shared medium.
3. Contention based Access//
   - HAS CSMA -CD ( ope in half duplex, dev detect collison n result in signal shared media, used sa BUS TOPOLOGY Ethernet

-CSMA-CA (collioion avodance// half duplex din, has dev time duration for transmission), know how long the medium will be unavailable, USED SA WAN

2. Controlled access // used in token ring n ARCNET

Question 7

To form a data link frame we need 3

Answer 7

1. Header // has 4
   Frame start n stop// beginning n End
   Adrressing// source n deti
   Type// encapnlayer 3
   Control // flow control
2. Data/ 1- contains frmwePayload
3. Trailer// 2 - for error detection ( transmission errors)