CPSC 441: Link Layer1. 2 Our Goals … r understand principles behind data link layer services: m...

CPSC 441 Link Layer 1


Our Goals hellip understand principles behind data link layer

services error detection correction sharing a broadcast channel multiple access link layer addressing done reliable data transfer flow control done

instantiation and implementation of various link layer technologies


Link Layer

Introduction and services (review)

Error detection and correction

Multiple access protocols

Ethernet

Hubs and switches PPP MPLS


Link Layer ReviewSome terminology hosts and routers are nodes communication channels

that connect adjacent nodes along communication path are links wired links wireless links LANs

layer-2 packet is a frame encapsulates datagram

ldquolinkrdquo

data-link layer has responsibility of transferring datagram from one node to adjacent node over a link


Link layer Review

Datagram transferred by different link protocols over different links eg Ethernet on first link frame relay on intermediate

links 80211 on last link

Each link protocol provides different services eg may or may not provide reliable data transfer over

link


Link Layer Services Review Framing link access

Reliable delivery between adjacent nodes

Flow Control

Error Detection

Error Correction

Half-duplex and full-duplex


Link Layer

Introduction and services



Link-Layer Addressing

Ethernet



Error DetectionEDC= Error Detection and Correction bits (redundancy)D = Data protected by error checking may include header fields

bull Error detection not 100 reliablebull protocol may miss some errors but rarelybull larger EDC field yields better detection and correction


Parity Checking

Single Bit ParityDetect single bit errors

Two Dimensional Bit ParityDetect and correct single bit errors

0 0


Cyclic Redundancy CheckPolynomial Codes

A (n+1)-bit message can be represented as a polynomial of degree n For example X = 10011010 M(X) =

So a sender and receiver can be considered to exchange polyns

Choose k+1 bit pattern (divisor) C(X) a polyn of degree k

goal choose k CRC bits R such that ltMRgt exactly divisible by C (modulo 2) receiver knows C divides ltMRgt by C If non-zero

remainder error detected can detect all burst errors less than k+1 bits

xxxx 347


CRC continued hellip

Goal design P(X) such that it is exactly divisible by C(X)

Multiply M(X) by xk (add k zerorsquos to the end of the message) to get T(X)

Divide T(X) by C(X) and find the remainder R(X) Subtract the remainder from T(X) to get P(X)

P(X) is now exactly divisible by C(X)

Remember ndash all additionsubtract use modulo-2 arithmetic


Link Layer





Ethernet



Multiple Access Links and Protocols

Two types of ldquolinksrdquo point-to-point

PPP for dial-up access point-to-point link between Ethernet switch and host

broadcast (shared wire or medium) traditional Ethernet upstream HFC 80211 wireless LAN


When are Multiple Access Protocols Required

single shared broadcast channel two or more simultaneous transmissions by nodes

interference collision if node receives two or more signals at the same

time (examples LANs Wireless-LANs)

multiple access protocol distributed algorithm that determines how nodes

share channel ie determine when node can transmit

communication about channel sharing must use channel itself no out-of-band channel for coordination


Ideal Multiple Access Protocol

Broadcast channel of rate R bps1 When one node wants to transmit it can send

at rate R2 When M nodes want to transmit each can

send at average rate RM3 Fully decentralized

no special node to coordinate transmissions no synchronization of clocks slots

4 Simple and easy to implement


Taxonomy of Multiple Access Control Protocols

Three broad classes Channel Partitioning

divide channel into smaller ldquopiecesrdquo (TDM FDM Code Division Multiple Access) ndash TDM FDM covered in chap 1

allocate piece to node for exclusive use

Random Access channel not divided allow collisions ldquorecoverrdquo from collisions

ldquoTaking turnsrdquo Nodes take turns but nodes with more to send can

take longer turns


Random Access Protocols

When node has packet to send transmit at full channel data rate R no a priori coordination among nodes

two or more transmitting nodes ldquocollisionrdquo random access MAC protocol specifies

how to detect collisions how to recover from collisions (eg via delayed

retransmissions)

Examples of random access MAC protocols slotted ALOHA ALOHA CSMA CSMACD CSMACA


Pure ALOHA Let nodes transmit whenever a frame arrives No synchronization among nodes

If collision retransmit after random delay

collision probability increases frame sent at t0 collides with other frames sent in [t0-

1t0+1]


Pure Aloha efficiencyP(success by given node) = P(node transmits)

P(no other node transmits in [p0-1p0]


= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)

hellip choosing optimum p and then letting n -gt infty

= 1(2e) = 18 Even worse


Slotted ALOHA

Assumptions all frames same size time is divided into

equal size slots time to transmit 1 frame

nodes start to transmit frames only at beginning of slots

nodes are synchronized if 2 or more nodes

transmit in slot all nodes detect collision

Operation when node obtains fresh

frame it transmits in next slot

no collision node can send new frame in next slot

if collision node retransmits frame in each subsequent slot with prob p until success


Slotted ALOHA

Pros single active node can

continuously transmit at full rate of channel

highly decentralized only slots in nodes need to be in sync

simple

Cons collisions wasting

slots idle slots nodes may be able to

detect collision in less than time to transmit packet

clock synchronization


Slotted Aloha efficiency

Suppose N nodes with many frames to send each transmits in slot with probability p

prob that node 1 has success in a slot = p(1-p)N-1

prob that any node has a success = Np(1-p)N-1

For max efficiency with N nodes find p that maximizes Np(1-p)N-1

For many nodes take limit of Np(1-p)N-1

as N goes to infinity gives 1e = 37

Efficiency is the long-run fraction of successful slots when there are many nodes each with many frames to send

At best channelused for useful transmissions 37of time


Carrier Sense Multiple Access (CSMA)

First listen transmit only if channel sensed to be idle

Can collisions occur in this scheme One possibility two nodes might attempt to transmit a

frame at the same time Another possibility


CSMACD (Collision Detection)CSMACD carrier sensing deferral as in

CSMA collisions detected within short time colliding transmissions aborted reducing

channel wastage collision detection

easy in wired LANs measure signal strengths compare transmitted received signals

difficult in wireless LANs receiver shut off while transmitting


ldquoTaking Turnsrdquo MAC protocolschannel partitioning MAC protocols

share channel efficiently and fairly at high load

inefficient at low load delay in channel access 1N bandwidth allocated even if only 1 active node

Random access MAC protocols efficient at low load single node can fully

utilize channel high load collision overhead

ldquotaking turnsrdquo protocolslook for best of both worlds


ldquoTaking Turnsrdquo MAC protocolsPolling master node

ldquoinvitesrdquo slave nodes to transmit in turn

concerns polling overhead latency single point of

failure (master)

Token passing control token passed

from one node to next sequentially

token message concerns

token overhead latency single point of failure

(token)


Summary of MAC protocols

What do you do with a shared media Channel Partitioning by time frequency or

codebull Time Division Frequency Division

Random partitioning (dynamic) bull ALOHA S-ALOHA CSMA CSMACDbull carrier sensing easy in some technologies (wire)

hard in others (wireless)bull CSMACD used in Ethernetbull CSMACA used in 80211

Taking Turnsbull polling from a central site token passing


Next Stop LAN Technologies

Data link layer so far services error detectioncorrection multiple

access

Next LAN technologies Ethernet hubs switches PPP


Link Layer





Ethernet



Ethernet

ldquodominantrdquo wired LAN technology cheap $20 for 100Mbs first widely used LAN technology Simpler cheaper than token LANs and ATM Kept up with speed race 10 Mbps ndash 10 Gbps


Star topology

Bus topology popular through mid 90s Now star topology prevails Connection choices hub or switch (more later)

hub orswitch


Ethernet Frame Structure (12)Sending adapter encapsulates IP datagram (or

other network layer protocol packet) in Ethernet frame

Preamble 7 bytes with pattern 10101010 followed by one

byte with pattern 10101011 used to synchronize receiver sender clock

rates


Ethernet Frame Structure (22) Addresses 6 bytes

if adapter receives frame with matching destination address or with broadcast address (eg ARP packet) it passes data in frame to net-layer protocol

otherwise adapter discards frame

Type indicates the higher layer protocol (mostly IP but others may be supported such as Novell IPX and AppleTalk)

CRC checked at receiver if error is detected the frame is simply dropped


Unreliable connectionless service Connectionless No handshaking between

sending and receiving adapter Unreliable receiving adapter doesnrsquot send

acks or nacks to sending adapter stream of datagrams passed to network layer can

have gaps gaps will be filled if app is using TCP otherwise app will see the gaps


Ethernet uses CSMACD

No slots adapter doesnrsquot

transmit if it senses that some other adapter is transmitting that is carrier sense

transmitting adapter aborts when it senses that another adapter is transmitting that is collision detection

Before attempting a retransmission adapter waits a random time that is random access


Ethernet CSMACD algorithm

1 Adaptor receives datagram from net layer amp creates frame

2 If adapter senses channel idle it starts to transmit frame If it senses channel busy waits until channel idle and then transmits

3 If adapter transmits entire frame without detecting another transmission the adapter is done with frame

4 If adapter detects another transmission while transmitting aborts and sends jam signal

5 After aborting adapter enters exponential backoff after the mth collision adapter chooses a K at random from 012hellip2m-1 Adapter waits K512 bit times and returns to Step 2


Ethernetrsquos CSMACD (more)

Jam Signal make sure all other transmitters are aware of collision 48 bits

Bit time 1 microsec for 10 Mbps Ethernet for K=1023 wait time is about 50 msec

Exponential Backoff Goal adapt retransmission

attempts to estimated current load heavy load random wait

will be longer first collision choose K

from 01 delay is K 512 bit transmission times

after second collision choose K from 0123hellip

after ten collisions choose K from 01234hellip1023

Seeinteract with Javaapplet on AWL Web sitehighly recommended


CSMACD efficiency tprop = max prop between 2 nodes in LAN

ttrans = time to transmit max-size frame

Efficiency goes to 1 as tprop goes to 0

Goes to 1 as ttrans goes to infinity Much better than ALOHA but still decentralized simple and cheap

transprop tt 51

1efficiency


10BaseT and 100BaseT 10100 Mbps rate latter called ldquofast ethernetrdquo T stands for Twisted Pair Nodes connect to a hub ldquostar topologyrdquo 100

m max distance between nodes and hub

twisted pair

hub


HubsHubs are essentially physical-layer repeaters

bits coming from one link go out all other links at the same rate no frame buffering no CSMACD at hub adapters detect collisions provides net management functionality

twisted pair

hub


Link Layer





Ethernet

Interconnections Hubs and switches

PPP MPLS


Interconnecting with hubs Backbone hub interconnects LAN segments Extends max distance between nodes But individual segment collision domains become one large

collision domain Canrsquot interconnect 10BaseT amp 100BaseT

hub

hubhub

hub


Switch Link layer device

stores and forwards Ethernet frames examines frame header and selectively forwards

frame based on MAC dest address when frame is to be forwarded on segment uses

CSMACD to access segment transparent

hosts are unaware of presence of switches plug-and-play self-learning

switches do not need to be configured


Forwarding

bull How do determine onto which LAN segment to forward framebull Looks like a routing problem

hub

hubhub

switch1

2 3


Self learning

A switch has a switch table entry in switch table

(MAC Address Interface Time Stamp) stale entries in table dropped (TTL can be 60

min) switch learns which hosts can be reached through

which interfaces when frame received switch ldquolearnsrdquo location

of sender incoming LAN segment records senderlocation pair in switch table


FilteringForwardingWhen switch receives a frame

index switch table using MAC dest addressif entry found for destination

then if dest on segment from which frame arrived

then drop the frame else forward the frame on interface indicated else flood

forward on all but the interface on which the frame arrived


Switch traffic isolation switch installation breaks subnet into LAN

segments switch filters packets

same-LAN-segment frames not usually forwarded onto other LAN segments

segments become separate collision domains

hub hub hub

switch

collision domain collision domain

collision domain


Switches dedicated access Switch with many

interfaces Hosts have direct

connection to switch No collisions full duplex

Switching A-to-Arsquo and B-to-Brsquo simultaneously no collisions

switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types

cut-through switching frame forwarded from input to output port without first collecting entire frameslight reduction in latencyDisadvantage

Store-and-forward combinations of shareddedicated

101001000 Mbps interfaces


Institutional network

hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server


Switches vs Routers both store-and-forward devices

routers network layer devices (examine network layer headers) switches are link layer devices

routers maintain routing tables implement routing algorithms

switches maintain switch tables implement filtering learning algorithms


Link Layer





Ethernet

Hubs and switches PPP (self-study) MPLS (self-study)


Point to Point Data Link Control one sender one receiver one link easier than

broadcast link no Media Access Control no need for explicit MAC addressing eg dialup link ISDN line

popular point-to-point DLC protocols PPP (point-to-point protocol) HDLC High level data link control (Data link

used to be considered ldquohigh layerrdquo in protocol stack

This is your READING assignment


Link Layer





Ethernet



Multi-Protocol Label Switching (MPLS)

initial goal speed up IP forwarding by using fixed length label (instead of IP address) to do forwarding borrowing ideas from Virtual Circuit (VC) approach but IP datagram still keeps IP address

PPP or Ethernet header

IP header remainder of link-layer frameMPLS header

label Exp S TTL

20 3 1 5


MPLS capable routers

aka label-switched router forwards packets to outgoing interface based

only on label value (donrsquot inspect IP address) MPLS forwarding table distinct from IP forwarding

tables signaling protocol needed to set up forwarding

RSVP-TE forwarding possible along paths that IP alone would

not allow (eg source-specific routing) use MPLS for traffic engineering

must co-exist with IP-only routers


R1R2

D

R3R4R5

0

1

00

A

R6

in out outlabel label dest interface 6 - A 0

in out outlabel label dest interface10 6 A 1

12 9 D 0

in out outlabel label dest interface 10 A 0

12 D 0

1

in out outlabel label dest interface 8 6 A 0

0

8 A 1

MPLS forwarding tables

Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review

Link Layer Services Review

Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA

Pure Aloha efficiency

Slotted ALOHA

Slide 21



CSMACD (Collision Detection)

ldquoTaking Turnsrdquo MAC protocols

Slide 26



Slide 29

Ethernet

Star topology

Ethernet Frame Structure (12)


Unreliable connectionless service




CSMACD efficiency

10BaseT and 100BaseT

Hubs

Slide 41

Interconnecting with hubs

Switch

Forwarding

Self learning

FilteringForwarding

Switch traffic isolation

Switches dedicated access

Switching types


Switches vs Routers

Slide 52

Point to Point Data Link Control

Slide 54





Our Goals hellip understand principles behind data link layer

services error detection correction sharing a broadcast channel multiple access link layer addressing done reliable data transfer flow control done

instantiation and implementation of various link layer technologies


Link Layer




Ethernet






ldquolinkrdquo



Link layer Review




link




Flow Control

Error Detection

Error Correction



Link Layer





Ethernet






Parity Checking



0 0








xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Link Layer




Ethernet






ldquolinkrdquo



Link layer Review




link




Flow Control

Error Detection

Error Correction



Link Layer





Ethernet






Parity Checking



0 0








xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54








ldquolinkrdquo



Link layer Review




link




Flow Control

Error Detection

Error Correction



Link Layer





Ethernet






Parity Checking



0 0








xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Link layer Review




link




Flow Control

Error Detection

Error Correction



Link Layer





Ethernet






Parity Checking



0 0








xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54







Flow Control

Error Detection

Error Correction



Link Layer





Ethernet






Parity Checking



0 0








xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Link Layer





Ethernet






Parity Checking



0 0








xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54








Parity Checking



0 0








xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54











xxxx 347









Link Layer





Ethernet





























take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

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Link Layer





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Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54












Link Layer





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take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

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Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


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rates









































transprop tt 51

1efficiency




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hub


Link Layer





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Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54































take longer turns






retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



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rates









































transprop tt 51

1efficiency




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Link Layer





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hub

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Link Layer





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Link Layer





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label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

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A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54









retransmissions)






1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




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hub




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hub


Link Layer





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hub

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Switching types






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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

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A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54








1t0+1]





= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




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hub




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hub


Link Layer





Ethernet


PPP MPLS




hub

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Switching types






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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

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A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54








= p (1-p)N-1 (1-p)N-1

= p (1-p)2(N-1)




Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

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Switching types






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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Slotted ALOHA











Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




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hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

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Switching types






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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

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A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Slotted ALOHA




simple





































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




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hub




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hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

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hubhub

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2 3


Self learning

















hub hub hub

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switch

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Arsquo

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Switching types






hub

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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

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A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54




































failure (master)





(token)











access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

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Forwarding


hub

hubhub

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2 3


Self learning

















hub hub hub

switch


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switch

A

Arsquo

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Switching types






hub

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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

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A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54














access



Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

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Forwarding


hub

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2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

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Switching types






hub

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to externalnetwork

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mail server

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Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Link Layer





Ethernet



Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

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Forwarding


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2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

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Brsquo

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Switching types






hub

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to externalnetwork

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mail server

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Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Ethernet



Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

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2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

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Switching types






hub

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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Star topology


hub orswitch






rates









































transprop tt 51

1efficiency




twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


hub

hubhub

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2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

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Switching types






hub

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to externalnetwork

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mail server

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Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54









rates









































transprop tt 51

1efficiency




twisted pair

hub




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hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


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hubhub

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2 3


Self learning

















hub hub hub

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collision domain






switch

A

Arsquo

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Brsquo

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Switching types






hub

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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

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A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54












































transprop tt 51

1efficiency




twisted pair

hub




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hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

hub









Forwarding


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hubhub

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2 3


Self learning

















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switch

A

Arsquo

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Brsquo

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Switching types






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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54







twisted pair

hub




twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

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2 3


Self learning

















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switch

A

Arsquo

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Switching types






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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54







twisted pair

hub


Link Layer





Ethernet


PPP MPLS




hub

hubhub

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hubhub

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2 3


Self learning

















hub hub hub

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A

Arsquo

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Switching types






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Link Layer





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Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Link Layer





Ethernet


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hub

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Switching types






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Link Layer





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Link Layer





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label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54







hub

hubhub

hub









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hubhub

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2 3


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A

Arsquo

B

Brsquo

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Switching types






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to externalnetwork

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web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54












Forwarding


hub

hubhub

switch1

2 3


Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Self learning

















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54















hub hub hub

switch


collision domain






switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54









switch

A

Arsquo

B

Brsquo

C

Crsquo


Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54





Switching types






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54






hub

hubhub

switch

to externalnetwork

router

IP subnet

mail server

web server







Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54










Link Layer





Ethernet









Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54











Link Layer





Ethernet







label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54









label Exp S TTL

20 3 1 5










R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54













R1R2

D

R3R4R5

0

1

00

A

R6



12 9 D 0


12 D 0

1


0

8 A 1


Slide 1

Our Goals hellip

Link Layer

Link Layer Review

Link layer Review


Slide 7

Error Detection

Parity Checking



Slide 12






Pure ALOHA


Slotted ALOHA

Slide 21





Slide 26



Slide 29

Ethernet

Star topology







CSMACD efficiency


Hubs

Slide 41


Switch

Forwarding

Self learning

FilteringForwarding



Switching types


Switches vs Routers

Slide 52


Slide 54




CPSC 441: Link Layer1. 2 Our Goals … r understand principles behind data link layer services: m...

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Transcript of CPSC 441: Link Layer1. 2 Our Goals … r understand principles behind data link layer services: m...