Read: 2.4 Read: 2.4 Problems: 2.1, 2.3, Web 4.2Problems: 2.1, 2.3, Web 4.2 Design #1 due Design #1 due 8 February (Async DL)8 February (Async DL)

Late = -1 per working dayLate = -1 per working day Quiz #1Quiz #1

<< 11 February (Async Distance Learning) 11 February (Async Distance Learning) Corrected quizzes due 13 February (Live)Corrected quizzes due 13 February (Live)

ECEN4533 Data CommunicationsECEN4533 Data CommunicationsLecture #13 6 February 2013Lecture #13 6 February 2013Dr. George ScheetsDr. George Scheets

ECEN4533 Data CommunicationsECEN4533 Data CommunicationsLecture #13 6 February 2013Lecture #13 6 February 2013Dr. George ScheetsDr. George Scheets

ECEN4533 Data CommunicationsLecture #14 8 February 2013Dr. George Scheets

ECEN4533 Data CommunicationsLecture #14 8 February 2013Dr. George Scheets

Problems: Web 4, 5, & 6Problems: Web 4, 5, & 6 Design #1 due 8 February (Async DL)Design #1 due 8 February (Async DL)

Late = -1 per working dayLate = -1 per working day Quiz #1Quiz #1

<< 11 February (Async Distance Learning) \ 11 February (Async Distance Learning) \ Corrected quizzes due 13 February (Live)Corrected quizzes due 13 February (Live)

Exam #1: 22 February (Live), Exam #1: 22 February (Live),

Various ProtocolsVarious Protocols EthernetEthernet

#1 on the wired LAN#1 on the wired LAN Exceptions in some Data CentersExceptions in some Data Centers

Had plenty of competition 'til mid-90'sHad plenty of competition 'til mid-90's Moving into MAN & WANMoving into MAN & WAN

LAN frame is encapsulated LAN frame is encapsulated

Frame RelayFrame Relay Introduced commercially in 1990Introduced commercially in 1990 Has its own Layer 2 Header FormatHas its own Layer 2 Header Format

In early 90'sIn early 90's• Ethernet, Token Ring, FDDI commonEthernet, Token Ring, FDDI common

• IP not yet dominant (Novell common)IP not yet dominant (Novell common)

Various ProtocolsVarious Protocols ATMATM

Hot protocol in mid 90'sHot protocol in mid 90's Complex compared to Frame RelayComplex compared to Frame Relay

Meant to haul all types of trafficMeant to haul all types of traffic 5 Classes of Service5 Classes of Service

Derided as too Complex by Internet FanaticsDerided as too Complex by Internet Fanatics But now Internet is being asked to move everythingBut now Internet is being asked to move everything Internet becoming more complexInternet becoming more complex

Various ProtocolsVarious Protocols InternetInternet

Hot protocol in 2000'sHot protocol in 2000's Commodity Internet Commodity Internet

Treats all traffic the sameTreats all traffic the same

Corporate InternetCorporate Internet Becoming more complexBecoming more complex

• DiffServ: Enables PrioritiesDiffServ: Enables PrioritiesNot Used on Commodity InternetNot Used on Commodity Internet

• Multi-Protocol Label SwitchingMulti-Protocol Label SwitchingEnables Virtual CircuitsEnables Virtual Circuits

Internet Traffic GrowthInternet Traffic Growth

source: "The Road to 100G Deployment", IEEE Communications Magazine, March 2010

InternetTraffic

2008 - 2009 Comparison

InternetTraffic

2008 - 2009 Comparison

sour

ce:

http

://w

ww

.san

dvin

e.co

ms

2011 Internet Traffic Profile2011 Internet Traffic Profile

Source: http://www.sandvine.com/downloads/documents/2011 Global Internet Phenomena Report.pdf

2011 Internet Traffic Profile2011 Internet Traffic Profile

Source: http://www.sandvine.com/downloads/documents/2011 Global Internet Phenomena Report.pdf

ISP Router OverloadISP Router OverloadSource:1 October 2007Network World

Fall 2011Level3

BGP entries375,550 IPv47,210 IPv6

Peak Traffic8.0 Tbps IPv4500 Mbps IPv6

RouterRouter Operates at OSI Layers 1-3Operates at OSI Layers 1-3 Communicate with adjacent RoutersCommunicate with adjacent Routers

Exchange "Hello" packets every 10 or so secondsExchange "Hello" packets every 10 or so seconds Exchange Routing info Exchange Routing info

immediately upon "Hello" failureimmediately upon "Hello" failure general updates several times a day independent of trafficgeneral updates several times a day independent of traffic

Use Routing info to generate a Hierarchical Routing Table Use Routing info to generate a Hierarchical Routing Table Example) ISP Backbone Routers Example) ISP Backbone Routers Must know how to get to Must know how to get to ibm.ucc.ibm.ucc.okstate.eduokstate.eduExample) OSU Campus Backbone RoutersExample) OSU Campus Backbone RoutersMust know how to get to Must know how to get to ibm.ibm.ucc.okstate.eduucc.okstate.edu

Switched EthernetSwitched Ethernet

TrunksAccess Lines

PC

PC

PC

PC

PC

PC

PC

SwitchedHub

SwitchedHub

SwitchedHub

PC

Pr

RSwitched

Hub

Packet formatting same as before.Only the Printer will see packets from the PC.

Switched EthernetSwitched Ethernet

TrunksAccess Lines

PC

PC

PC

PC

PC

PC

PC

Packets need to cross a network boundary.

SwitchedHub

SwitchedHub

PC

Pr

R

SwitchedHub

Ex) Leased LinesEx) Leased Lines

OKC

Detroit

NYC

Carrier LeasedLine Network

Router

From/ToFrom/To OKCOKC DETDET NYCNYC

OKCOKC -- 144144 7676

DETDET 8888 -- 2828

NYCNYC 112112 3434 --

320 Kbps

128 Kbps

256 KbpsTraffic Matrix (Bursty Data)

Suppose:*BW available in 64 Kbps chunks (64, 128, 192, 256, 320, 384, 448, etc.)*Maximum load (traffic/BW) = 50%

Ex) Leased LinesEx) Leased Lines

OKC

Detroit

NYC

Carrier LeasedLine Network

Router

384 Kbps

From/ToFrom/To OKCOKC DETDET NYCNYC

OKCOKC -- 144144 7676

DETDET 8888 -- 2828

NYCNYC 112112 3434 --

320 Kbps

Suppose:*BW available in 64 Kbps chunks (64, 128, 192, 256, 320, 384, 448, etc.)*Maximum load (traffic/BW) = 50%

OKC

Detroit

NYC

Carrier LeasedLine Network

Router

576 Kbps

ISP

448 Kbps

Ex) Leased Lines with Internet thru OKCEx) Leased Lines with Internet thru OKC

From/ToFrom/To OKCOKC DETDET NYCNYC ISPISP

OKCOKC -- 144144 7676 6060

DETDET 8888 -- 2828 5050

NYCNYC 112112 3434 -- 4040

ISPISP 110110 100100 9090 --

640 Kbps

Ex) Commodity InternetCorporate Connectivity

Ex) Commodity InternetCorporate Connectivity

OKC

Detroit

NYC

ISP Network

Router

448 Kbps

384 Kbps

320 Kbps

From/ToFrom/To OKCOKC DETDET NYCNYC

OKCOKC -- 144144 7676

DETDET 8888 -- 2828

NYCNYC 112112 3434 --

Ex) Commodity InternetCorporate & Internet ConnectivityEx) Commodity InternetCorporate & Internet Connectivity

OKC

Detroit

NYC

ISP Network

Router

640 Kbps

576 Kbps

448 KbpsFrom/ToFrom/To OKCOKC DETDET NYCNYC ISPISP

OKCOKC -- 144144 7676 6060

DETDET 8888 -- 2828 5050

NYCNYC 112112 3434 -- 4040

ISPISP 110110 100100 9090 --

320/280 I/O @ OKC → 640 Kbps194/186 I/O @ NYC → 448 Kbps278/166 I/O @ DET → 576 Kbps

LAN

PC

LAN

PC

Virtual Circuit BackboneVirtual Circuit Backbone

VC Switch

VC #2

Suppose we need to connect to three LAN's.

LAN

Server

VC #1

Ex) Frame Relay, ATM, MPLS, Carrier EthernetCorporate ConnectivityEx) Frame Relay, ATM, MPLS, Carrier EthernetCorporate Connectivity

OKC

Detroit

NYC

Carrier Frame Relay,ATM, Ethernet, or MPLS Internet Network.

PVC, OKC - D

etroit

PVC, NYC - OKC

576 Kbps

384 Kbps

320 Kbps

From/ToFrom/To OKCOKC DETDET NYCNYC

OKCOKC -- 144144 7676

DETDET 8888 -- 2828

NYCNYC 112112 3434 --

OKC Outbound = 220 +28 +34 KbpsOKC Inbound = 200 + 28 +34 KbpsLeased Line Size > 2*282 = 564 KbpsLeased Line = 576 Kbps minimum.

OKC

Detroit

NYC

Carrier Ethernet, ATM, MPLS, or FR Network

Resized

PVC, OKC - D

etroit

ResizedPVC, NYC - OKC

Router

ISP

Ex) Carrier Ethernet, FR, ATM, MPLSCorporate & Internet ConnectivityEx) Carrier Ethernet, FR, ATM, MPLSCorporate & Internet Connectivity

From/ToFrom/To OKCOKC DETDET NYCNYC ISPISP

OKCOKC -- 144144 7676 6060

DETDET 8888 -- 2828 5050

NYCNYC 112112 3434 -- 4040

ISPISP 110110 100100 9090 --

640 Kbps

576 Kbps

448 Kbps

OKC FR Leased Line must handle NYC & Det traffic ↔ Internet,OKC ↔ corporate, and Detroit/NYC pass-thru traffic.

960 Kbps

Leased Line at OKC ↔ FR NetLeased Line at OKC ↔ FR Net OutboundOutbound

OKCOKC→Det 144→Det 144 OKC→NYC 76 OKC→NYC 76 Det→NYC 28Det→NYC 28 NYC→Det 34NYC→Det 34 ISP→Det 100ISP→Det 100 ISP→NYC 90ISP→NYC 90

From/ToFrom/To OKCOKC DETDET NYCNYC ISPISP

OKCOKC -- 144144 7676 6060

DETDET 8888 -- 2828 5050

NYCNYC 112112 3434 -- 4040

ISPISP 110110 100100 9090 --

InboundInbound Det→OKC 88Det→OKC 88 Det→NYC 28Det→NYC 28 Det→ISP 50Det→ISP 50 NYC→OKC 112NYC→OKC 112 NYC→Det 34NYC→Det 34 NYC→ISP 40 NYC→ISP 40

Total Outbound = 472 KbpsTotal Inbound = 352 KbpsLeased Line Size > 944 KbpsLeased Line = 960 Kbps minimum.

OKC

ISPDetroit

NYC

Circuit Switched TDMCircuit Switched TDM

LeasedLine

Cross-Connect 100 Mbps Trunk

?? 1.54 Mbps ConnectionsP(Access Line is Active) = 10%

Trunk Bandwidth is assigned based on peak input rates. Can support 64 access lines.

Queue LengthQueue Length

100,000,000 bps output trunk100,000,000 bps output trunk 100,000,001 bps average input100,000,001 bps average input Average Input rate > Output rateAverage Input rate > Output rate Queue Length builds upQueue Length builds up

(without bound, in theory)(without bound, in theory)

Queue LengthQueue Length

100,000,000 bps output trunk100,000,000 bps output trunk 99,999,999 bps average input99,999,999 bps average input Average Input rate < Output rateAverage Input rate < Output rate Queue Length not infinite...Queue Length not infinite...

...but ...but veryvery large large

Queue Length @ 100% LoadOutput capacity = 7 units

Input = 7 units on average (two dice rolled)

Queue Length @ 100% LoadOutput capacity = 7 units

Input = 7 units on average (two dice rolled)

t1: input = 4, output = 4, queue = 0t1: input = 4, output = 4, queue = 0 t2: input = 5, output = 5, queue = 0t2: input = 5, output = 5, queue = 0 t3: input = 4, output = 4, queue = 0t3: input = 4, output = 4, queue = 0 t4: input = 7, output = 7, queue = 0t4: input = 7, output = 7, queue = 0 t5: input = 11, output = 7, queue = 4t5: input = 11, output = 7, queue = 4 t6: input = 10, output = 7, queue = 7t6: input = 10, output = 7, queue = 7 t7: input = 6, output = 7, queue = 6t7: input = 6, output = 7, queue = 6 t8: input = 5, output = 7, queue = 4t8: input = 5, output = 7, queue = 4 t9: input = 8, output = 7, queue = 5t9: input = 8, output = 7, queue = 5 t10: input = 11, output = 7, queue = 9t10: input = 11, output = 7, queue = 9

This queue will tend to get very large over time.This queue will tend to get very large over time.

Queue Length @100% LoadWill tend to increase w/o Bound.

Queue Length @100% LoadWill tend to increase w/o Bound.

0 2 105

4 105

6 105

8 105

1 106

0

2000

40003.409 10

3

0

queue5 j

1 1060 j 5

0 2 105

4 105

6 105

8 105

1 106

0

1000

20001.983 10

3

0

queue5 j

1 1060 j 5

Packet Switched StatMuxPacket Switched StatMux

Routeror

Switch 100 Mbps Trunk

?? 1.54 Mbps ConnectionsP(Access Line is Active) = 10%

Trunk Bandwidth assigned based on average input rates. Can theoretically support 649 access lines.

Note if all inputs active, input = 999.5 Mbps

Probability Density FunctionsProbability Density Functions A Histogram is an estimate of the PDFA Histogram is an estimate of the PDF Important PDF's for NetworkingImportant PDF's for Networking

GaussianGaussian Very common in the Real WorldVery common in the Real World

BinomialBinomial Individual Experiment has 2 statesIndividual Experiment has 2 states Experiment results are IndependentExperiment results are Independent Interested in # of successful experiments, Interested in # of successful experiments,

not specific ordernot specific order

ExponentialExponential Not a bad model for packet sizesNot a bad model for packet sizes

PoissonPoisson

1995 OSU Backbone Packet Histogram1995 OSU Backbone Packet Histogram

Looks somewhat exponential.

2004 OSU Backbone Packet Histogram2004 OSU Backbone Packet Histogram

Still looks sort of exponential, but less

so than before,

IM Traffic Message SizeIM Traffic Message Size

Actual Traffic - Packet Size PDF

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0 20 40 60 80 100 120 140 160

Bytes

Pro

bability

Traffic in 0.1 second intervalsTraffic in 0.1 second intervals