A note on the use of these ppt slides:
We’re making these slides freely available to all (faculty, students, readers).
They’re in PowerPoint form so you see the animations; and can add, modify,
and delete slides (including this one) and slide content to suit your needs.
They obviously represent a lot of work on our part. In return for use, we only
ask the following:
v If you use these slides (e.g., in a class) that you mention their source
(after all, we’d like people to use our book!)
v If you post any slides on a www site, that you note that they are adapted
from (or perhaps identical to) our slides, and note our copyright of this
material.
Thanks and enjoy! JFK/KWR
All material copyright 1996-2012
J.F Kurose and K.W. Ross, All Rights Reserved
Introduction 1-1
v
PC
mobile network
server
§
wireless
laptop
§
global ISP
smartphonev
§
home
network
regional ISP
wireless
links
wired
links
§
v
§
router
§
institutional
network
Introduction 1-2
Web-enabled toaster +
weather forecaster
IP picture frame
http://www.ceiva.com/
Tweet-a-watt:
monitor energy use
Slingbox: watch,
control cable TV remotely
Internet
refrigerator
Internet phones
Introduction 1-3
mobile network
v
§
global ISP
v
home
network
regional ISP
§
v
§
institutional
network
§
Introduction 1-4
v
mobile network
§
global ISP
v
home
network
§
regional ISP
§
institutional
network
Introduction 1-5
v
v
v
v
v
Introduction 1-6
Hi
TCP connection
request
Hi
TCP connection
response
Got the
time?
Get http://www.awl.com/kurose-ross
2:00
<file>
time
Introduction 1-7
mobile network
v
§
global ISP
§
home
network
regional ISP
v
v
§
§
institutional
network
Introduction 1-8
v
v
v
v
v
Introduction 1-9
central office
DSL splitter
modem
voice, data transmitted
at different frequencies over
dedicated line to central office
telephone
network
DSLAM
ISP
DSL access
multiplexer
v
v
§
§
v
v
v
Introduction 1-10
cable headend
…
cable splitter
modem
V
I
D
E
O
V
I
D
E
O
V
I
D
E
O
V
I
D
E
O
V
I
D
E
O
V
I
D
E
O
D
A
T
A
C
O
N
D T
A R
T O
A L
1
2
3
4
5
6
7
8
9
Channels
Introduction 1-11
cable headend
…
cable splitter
modem
data, TV transmitted at different frequencies over shared
cable distribution network (i.e. every packet sent by the
head end travels downstream on every link to
every home and reverse way, too)
CMTS
cable modem
termination system
ISP
v
§
v
§
§
Introduction 1-12
wireless
devices
to/from headend or
central office
often combined
in single box
cable or DSL modem
wireless access
point (54 Mbps)
router, firewall, NAT
wired Ethernet (100 Mbps)
Introduction 1-13
institutional link to
ISP (Internet)
institutional router
Ethernet
switch
institutional mail,
web servers
v
v
v
Introduction 1-14
v
§
§
§
§
§
§
to Internet
to Internet
Introduction 1-15
two packets,
L bits each
v
v
2 1
v
R: link transmission rate
host
§
packet
transmission
delay
=
time needed to
transmit L-bit
packet into link
=
L (bits)
R (bits/sec)
1-16
v
v
v
v
§
v
v
§
Introduction 1-17
v
v
v
v
§
v
v
v
§
v
§
§
§
high cost of optical devices such as
transmitters, receivers, and switches
§
Introduction 1-18
v
v
§
v
v
v
§
v
v
§
§
§
§
v
§
§
§
Introduction 1-19
v
v
§
§
§
Introduction 1-20
L bits
per packet
source
3 2 1
R bps
R bps
destination
v
v
§
v
v
v
end-end delay = 2L/R (assuming zero
propagation delay)
(cf. total elapse time = 4L/R)
generally, end-end delay = N*(L/R)
(where, N = # of links)
delay for P packets sent over a series of N
links? (P2 on p71)
§
§
Introduction 1-21
A
B
C
R = 100 Mb/s
R = 1.5 Mb/s
queue of packets
waiting for output link
D
E
v
v
§
§
§
Introduction 1-22
§
routing algorithm
local forwarding table
header value output link
0100
0101
0111
1001
3
2
2
1
1
3 2
11
01
dest address in arriving
packet’s header
Network Layer 4-23
v
§
v
§
v
v
Introduction 1-24
Example:
FDM (Frequency-Division Multiplexing) 4 users
frequency
time
TDM (Time-Division Multiplexing)
frequency
time
Introduction 1-25
v
§
§
v
§
§
v
§
§
Introduction 1-26
v
§
v
v
v
v
v
access
net
…
access
net
access
net
…
access
net
access
net
access
net
access
net
…
…
access
net
access
net
access
net
access
net
access
net
access
net
access
net
…
access
net
access
net
…
access
net
access
net
…
access
net
access
net
…
access
net
…
…
access
net
access
net
…
…
connecting each access ISP
to each other directly doesn’t
scale: O(N2) connections.
…
…
access
net
access
net
access
net
access
net
access
net
access
net
access
net
…
…
access
net
access
net
…
and provider ISPs have economic agreement.
access
net
…
access
net
access
net
Customer
…
access
net
access
net
access
net
…
…
access
net
global
ISP
access
net
access
net
access
net
access
net
access
net
access
net
access
net
…
access
net
access
net
…
access
net
…
access
net
…
access
net
access
net
access
net
access
net
access
net
ISP A
…
…
access
net
ISP C
access
net
access
net
access
net
access
net
access
net
…
…
access
net
access
net
ISP B
access
net
access
net
…
access
net
access
net
Internet exchange point
…
access
net
access
net
IXP
access
net
access
net
ISP A
…
…
IXP
access
net
ISP C
access
net
peering link
access
net
access
net
access
net
access
net
…
…
access
net
access
net
ISP B
access
net
access
net
…
…
access
net
access
net
access
net
access
net
IXP
access
net
access
net
ISP A
…
…
IXP
access
net
ISP C
access
net
access
net
regional net
access
net
access
net
access
net
…
…
access
net
access
net
ISP B
access
net
access
net
…
…
access
net
access
net
access
net
access
net
IXP
access
net
access
net
Content provider network
IXP
access
net
access
net
ISP B
ISP B
access
net
access
net
regional net
access
net
access
net
access
net
…
…
access
net
…
…
ISP A
access
net
Tier 1 ISP
Tier 1 ISP
Regional ISP
access
ISP
access
ISP
access
ISP
access
ISP
Google
Regional ISP
access
ISP
access
ISP
access
ISP
access
ISP
v
§
§
Introduction 1-35
POP: point-of-presence
to/from backbone
peering
…
…
…
…
…
to/from customers
Introduction 1-36
v
v
packet being transmitted (delay)
A
B
packets queueing (delay)
free (available) buffers: arriving packets
dropped (loss) if no free buffers
Introduction 1-37
transmission
A
propagation
B
nodal
processing
§
queueing
§
§
§
§
Introduction 1-38
transmission
A
propagation
B
nodal
processing
queueing
§
§
§
§
§
dtrans and dprop
very different
§
Introduction 1-39
100 km
ten-car
caravan
v
100 km
toll
booth
toll
booth
§
v
§
v
v
§
Introduction 1-40
100 km
ten-car
caravan
toll
booth
100 km
toll
booth
v
v
v
§
Introduction 1-41
v
v
v
average queuing
delay
v
traffic intensity
= La/R
La/R ~ 0
Introduction 1-42
buffer
(waiting area)
A
packet being transmitted
B
packet arriving to
full buffer is lost
Introduction 1-43
v
v
traceroute
§
§
§
3 probes
3 probes
3 probes
Introduction 1-44
traceroute: gaia.cs.umass.edu to www.eurecom.fr
3 delay measurements from
gaia.cs.umass.edu to cs-gw.cs.umass.edu
1 cs-gw (128.119.240.254) 1 ms 1 ms 2 ms
2 border1-rt-fa5-1-0.gw.umass.edu (128.119.3.145) 1 ms 1 ms 2 ms
3 cht-vbns.gw.umass.edu (128.119.3.130) 6 ms 5 ms 5 ms
4 jn1-at1-0-0-19.wor.vbns.net (204.147.132.129) 16 ms 11 ms 13 ms
5 jn1-so7-0-0-0.wae.vbns.net (204.147.136.136) 21 ms 18 ms 18 ms
6 abilene-vbns.abilene.ucaid.edu (198.32.11.9) 22 ms 18 ms 22 ms
7 nycm-wash.abilene.ucaid.edu (198.32.8.46) 22 ms 22 ms 22 ms trans-oceanic
8 62.40.103.253 (62.40.103.253) 104 ms 109 ms 106 ms
link
9 de2-1.de1.de.geant.net (62.40.96.129) 109 ms 102 ms 104 ms
10 de.fr1.fr.geant.net (62.40.96.50) 113 ms 121 ms 114 ms
11 renater-gw.fr1.fr.geant.net (62.40.103.54) 112 ms 114 ms 112 ms
12 nio-n2.cssi.renater.fr (193.51.206.13) 111 ms 114 ms 116 ms
13 nice.cssi.renater.fr (195.220.98.102) 123 ms 125 ms 124 ms
14 r3t2-nice.cssi.renater.fr (195.220.98.110) 126 ms 126 ms 124 ms
15 eurecom-valbonne.r3t2.ft.net (193.48.50.54) 135 ms 128 ms 133 ms
16 194.214.211.25 (194.214.211.25) 126 ms 128 ms 126 ms
17 * * *
* means no response (probe lost, router not replying)
18 * * *
19 fantasia.eurecom.fr (193.55.113.142) 132 ms 128 ms 136 ms
Introduction 1-45
v
v
§
§
è
Introduction 1-46
v
Rs bits/sec
Rc bits/sec
Rs bits/sec
Rc bits/sec
v
Introduction 1-47
v
Rs
Rs
Rs
v
R
Rc
Rc
Rc
10 connections (fairly) share
backbone bottleneck link R bits/sec
Introduction 1-48
§
§
§
§
§
§
Introduction 1-49
v
ticket (purchase)
ticket (complain)
baggage (check)
baggage (claim)
gates (load)
gates (unload)
runway takeoff
runway landing
airplane routing
airplane routing
airplane routing
v
v
Introduction 1-50
ticket (purchase)
ticket (complain)
ticket
baggage (check)
baggage (claim
baggage
gates (load)
gates (unload)
gate
runway (takeoff)
runway (land)
takeoff/landing
airplane routing
airplane routing
airplane routing
departure
airport
airplane routing
airplane routing
intermediate air-traffic
control centers
arrival
airport
v
§
§
v
v
Introduction 1-51
v
§
v
§
§
v
§
§
Introduction 1-52
v
§
§
application
§
transport
v
network
§
•
link
•
physical
§
•
•
§
Introduction 1-53
v
§
application
§
transport
network
§
link
v
§
physical
§
v
Introduction 1-54
v
v
application
presentation
session
v
transport
v
network
link
v
physical
v
§
§
Introduction 1-55
source
message
segment
M
Ht
M
datagram Hn Ht
frame Hl Hn Ht
M
M
application
transport
network
link
physical
link
physical
switch
M
Ht
M
Hn Ht
M
Hl Hn Ht
M
destination
Hn Ht
M
application
transport
network
link
physical
Hl Hn Ht
M
network
link
physical
Hn Ht
M
router
Introduction 1-56
v
è
v
§
§
Introduction 1-57
Introduction 1-58