ECEN5553 Telecom SystemsDr. George ScheetsWeek 6Readings:[12a] "The Real Story of Stuxnet"[12b] "Everything You Know About Cyberwar is Wrong"[12c] "How do the FBI and Secret Service Know Your Network is

Breeched Before You Do?"[13a] "Can You Trust Your Fridge?"[13b] "Disaster as CryptoWall encrypts US firm's entire

server installation"[13c] "ARIN Finally Runs Out of IPv4 Addresses"

Exam #1 No later than 28 September (Remote DL)Results to date (90 points) Hi = 81.4, Low = 46.4, Ave = 68.98, σ = 10.63A > 78, B > 66, C > 57, D > 48 (Tentative)

utline 7 October 2015, Lecture 22 (Live)No later than 14 October (Remote DL)

ECEN5553 Telecom SystemsDr. George ScheetsWeek 6Readings:[12a] "The Real Story of Stuxnet"[12b] "Everything You Know About Cyberwar is Wrong"[12c] "How do the FBI and Secret Service Know Your Network is

Breeched Before You Do?"[13a] "Can You Trust Your Fridge?"[13b] "Disaster as CryptoWall encrypts US firm's entire

server installation"[13c] "ARIN Finally Runs Out of IPv4 Addresses"

Exam #1 No later than 28 September (Remote DL)Results to date (90 points) Hi = 81.4, Low = 46.4, Ave = 68.98, σ = 10.63A > 78, B > 66, C > 57, D > 48 (Tentative)

utline 7 October 2015, Lecture 22 (Live)No later than 14 October (Remote DL)

Exam #1Exam #1 GradingGrading

Lost points? No comments? → Insufficient info providedLost points? No comments? → Insufficient info provided Rule of Thumb: "X" point question needs Rule of Thumb: "X" point question needs >> "X" facts "X" facts

Lost points? Comments? Your score ≈ % correctLost points? Comments? Your score ≈ % correct Not happy with your score? Did you…Not happy with your score? Did you…

Start studying at the last minute?Start studying at the last minute? Read assigned articles?Read assigned articles? Answer the question asked?Answer the question asked? Use the space provided?Use the space provided?

Leave the instructor with impression you could've said moreLeave the instructor with impression you could've said more

There is plenty of time to RecoverThere is plenty of time to Recover 365 points remain to be claimed365 points remain to be claimed

OutlinesReceived

due 7 October (local)14 October (remote)

OutlinesReceived

due 7 October (local)14 October (remote)

18 %

WAN Design (Link Reduction)WAN Design (Link Reduction)

Start with Traffic MatrixStart with Traffic Matrix Examine Full MeshExamine Full Mesh Consider eliminating lightly used linksConsider eliminating lightly used links

Reroute affected trafficReroute affected traffic Compare costs at each iterationCompare costs at each iteration

WAN Connectivity OptionsWAN Connectivity Options

InternetInternet Routers are packet awareRouters are packet aware Datagrams are assigned trunk BW via StatMuxDatagrams are assigned trunk BW via StatMux

BW required based more so on BW required based more so on averageaverage input rates input rates

Each packet individually routed Each packet individually routed MPLS enabled networks can use Virtual CircuitsMPLS enabled networks can use Virtual Circuits

Pricing a function of connection sizePricing a function of connection size & Possibly QoS if MPLS and/or DiffServe used& Possibly QoS if MPLS and/or DiffServe used

Ex) Commodity InternetCorporate Connectivity

Ex) Commodity InternetCorporate Connectivity

Local Carriers dedicate bandwidthto our use. ISP provides random Packet Switched StatMux connectivity via datagrams.

OKC

Detroit

NYC

ISP Network

Router

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 --

310/280 I/O @ OKC → 640 Kbps194/186 I/O @ NYC → 448 Kbps278/166 I/O @ DET → 576 Kbps

Ex) IP with QoS Corporate & Commodity Internet Connectivity

Ex) IP with QoS Corporate & Commodity Internet Connectivity

OKC

Detroit

NYC

Internet ServiceProvider Network

MPLS VC, OKC - D

etroit

MPLS VC, NYC - OKC

768 Kbps

Detroit & NYC: No change.OKC: Port Speed must be bumped torelay Detroit ↔ NYC corporate traffic.

From/ToFrom/To OKCOKC DETDET NYCNYC ISPISP

OKCOKC -- 144144 7676 6060

DETDET 8888 -- 2828 5050

NYCNYC 112112 3434 -- 4040

ISPISP 110110 100100 9090 --

576 Kbps

448 Kbps

Leased Line at OKC ↔ ISPLeased Line at OKC ↔ ISP OutboundOutbound

OKCOKC→Det 144→Det 144 OKC→NYC 76 OKC→NYC 76 OKC→ISP 60OKC→ISP 60 Det →NYC 28Det →NYC 28 NYC → Det 34NYC → Det 34

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 NYC→OKC 112NYC→OKC 112 NYC→Det 34NYC→Det 34 ISP → OKC 110ISP → OKC 110

Total Outbound = 342 KbpsTotal Inbound = 372 KbpsLeased Line Size > 744 KbpsLeased Line = 768 Kbps minimum.

Carrier Leased Line NetworkCarrier Leased Line Network

Carrier reserves BW from pool for our use.Ex) For a 384 Kbps connection, Cross-Connects assign 6 byte sized TDM time slots 8000 times/second = 6*8*8000 = 384 Kbps.

Cross-ConnectCross-Connect

TrunksLeased LineByte

Aware

Internet Service Provider BackboneInternet Service Provider Backbone

Router

TrunksLeased Line

ISP Routers assign BW for our use on Random, as needed basis via StatMux & Packet Switching.

PacketAware

LAN

LAN

Internet Service Provider NetworkInternet Service Provider Network

Corporate customers might attachvia Edge Router & Leased Lines.

RouterRouter

TrunksLeased Line

PC

WS

Internet (Inside the Cloud)Internet (Inside the Cloud) Infinite BuffersInfinite Buffers

"OK" so long as Average Offered Input Rate"OK" so long as Average Offered Input Rate< Output Line Speed< Output Line Speed

InternetRouter

100 Mbps Trunk?? 1.54 Mbps Connections

P(Access Line is Active) = 10%

How many access lines can this switch support?100 Mbps/154 Kbps = 649 (theoretically)

Internet (Inside the Cloud)Internet (Inside the Cloud) Negligible BuffersNegligible Buffers

OK so long as Instantaneous Offered Input Rate OK so long as Instantaneous Offered Input Rate < Output Line Speed< Output Line Speed

100 Mbps Trunk?? 1.54 Mbps Connections

P(Access Line is Active) = 10%

How many access lines can this switch support?With 404 users, 99.99% sure Input Rate < Line Speed

InternetRouter

Bounds on Packet Switch Carrying Capacity 100 Mbps Trunk, 1.54 Mbps Inputs

with 154 Kbps average loads

Bounds on Packet Switch Carrying Capacity 100 Mbps Trunk, 1.54 Mbps Inputs

with 154 Kbps average loads

LowerLower UpperUpper90%90% 553 553 64964999%99% 485 485 64964999.9%99.9% 439 439 64964999.99%99.99% 404 404 649649In

stan

tan

eou

sIn

pu

t <

Lin

eS

pee

d

Where switch could operate

Where switch probably operates

Queue Size: Correlated vs Uncorrelated Identical Loads (traffic carried/line speed)

Queue Size: Correlated vs Uncorrelated Identical Loads (traffic carried/line speed)

mean(queue)=135.6

mean(queue)=32.80

Correlated: Long Term Bursts

Uncorrelated: Random Input

The negligiblebuffer analysisdoes not account for longterm bursts.

Real world switcheshave finite buffers.Required size to prevent droppedpackets depends onlength of burst.

Carrier Leased Line NetworkCarrier Leased Line Network

Cross-ConnectCross-Connect

TrunksLeased LineByte

Aware

LAN

PC

LAN

WSCorporate customers might attachvia Edge Router & Leased Lines.

Leased Lines (TDM)Leased Lines (TDM)

LeasedLine

Cross-Connect

32

1

32

1

3 2 13 2 1

TDM time slots are moved from input to outputTDM time slots are moved from input to output TDM switch is not "packet aware"TDM switch is not "packet aware" Time slots are allocated whether or not there is any traffic on themTime slots are allocated whether or not there is any traffic on them

Circuit Switched connections waste bandwidth for bursty traffic.Circuit Switched connections waste bandwidth for bursty traffic.

time

trafficNYCto OKC

1.54 Mbps Line Speed

146 Kbps Average

Idle Time >> Active Time

Leased Lines (Inside the Cloud)Leased Lines (Inside the Cloud) ExampleExample

LeasedLine

Cross-Connect100 Mbps Trunk?? 1.54 Mbps Connections

P(Access Line is Active) = 10%

How many access lines can this switch support?64 (100% input bps < trunk bps)

Given 100 Mbps of Bandwidth...Given 100 Mbps of Bandwidth... 6464 1.54 Mbps Circuit Switched1.54 Mbps Circuit Switched

TDM Customers withTDM Customers with154 Kbps average load &154 Kbps average load &100% availability100% availability

404 404 - 649- 649 1.54 Mbps Packet Switched1.54 Mbps Packet SwitchedStatMux Customers withStatMux Customers with154 Kbps average load &154 Kbps average load &99.99% availability99.99% availability

More Bursty Data Traffic can be moved with the Packet Switched StatMux network.

64 x 154 Kbps =9.856 Mbps

404 x 154 Kbps =62.22 Mbps

Switched Network Carrying CapacitiesSwitched Network Carrying Capacities

0% Bursty 100% Bursty100% Fixed Rate 0% Fixed Rate

Offered Load

Carrying Capacity

Circuit Switch TDM

Packet Switch StatMux

Network Cost...Network Cost...

Can be spread over 64 Leased Line customersCan be spread over 64 Leased Line customers Can be spread over 404 Internet customersCan be spread over 404 Internet customers The InternetThe Internet

Is a Packet Switched StatMux networkIs a Packet Switched StatMux networkLargely hauling bursty data trafficLargely hauling bursty data trafficEffectively hauling bursty data trafficEffectively hauling bursty data traffic

Inexpensive (compared to a Leased Line) Inexpensive (compared to a Leased Line)

Internet PerformanceInternet Performance

0% 100%Trunk Offered Load

Number of dropped packets

Average Delay fordelivered packets

This type of plot valid for all real world full duplex

statistically multiplexed switches:Ethernet, Internet, Frame Relay

Internet PerformanceEffect of priorities

Internet PerformanceEffect of priorities

0% 100%Trunk Offered Load

Average Delay forlow priority packetsAverage Delay for alldelivered packetsAverage Delay forhigh priority packets

Internet PerformanceEffect of priorities

Internet PerformanceEffect of priorities

0% 100%Trunk Offered Load

Number of low priority dropsNumber of dropped packetsNumber ofhigh priority drops

Internet Backbone EngineeringInternet Backbone Engineering

Option A)Option A)Deploy ‘best effort’ RoutersDeploy ‘best effort’ RoutersRapidly Deploy Trunk BandwidthRapidly Deploy Trunk BandwidthKeep Trunks Lightly LoadedKeep Trunks Lightly Loaded Delays will be smallDelays will be small Dropped packets will be fewDropped packets will be few Quality fine for all trafficQuality fine for all traffic

Backbone Engineering: Option ABackbone Engineering: Option A

0% 100%

Number of dropped packets

Average Delay fordelivered packets

Keep Trunks Lightly Loaded

Internet Backbone EngineeringInternet Backbone Engineering

Option B)Option B)Deploy more complex QoS enabledDeploy more complex QoS enabled

Routers Routers Deploy fewer, more heavily loadedDeploy fewer, more heavily loaded

Trunks Trunks Give preferential treatment to Give preferential treatment to

interactive Voice/Videointeractive Voice/Video

Option A seems to be preferred todayOption A seems to be preferred today

Backbone Engineering: Option B High Priority delay at 50% Load = Delay for all traffic at 20% Load

Backbone Engineering: Option B High Priority delay at 50% Load = Delay for all traffic at 20% Load

0% 70%

Heavier Trunk Load

Average Delay forlow priority packetsAverage Delay for alldelivered packetsAverage Delay forhigh priority packets

Frame RelayFrame Relay ANSI Standard covering OSI Layer 2ANSI Standard covering OSI Layer 2 Accessed by RoutersAccessed by Routers Derived from X.25 ProtocolDerived from X.25 Protocol

Dumps almost all error checkingDumps almost all error checking Requires fiber on the long haulRequires fiber on the long haul Uses Uses Virtual Circuits (VC’s)Virtual Circuits (VC’s)

VC differs from DatagramVC differs from DatagramPath thru network set up in advancePath thru network set up in advance Requires Carrier interventionRequires Carrier intervention

Frame RelayFrame Relay 1st Commercial Deployment 19901st Commercial Deployment 1990

WilTel → Worldcom→ WilTel → Worldcom→ bankruptbankrupt → Verizon → Verizon Cheaper alternative to Leased LinesCheaper alternative to Leased Lines Faster alternative to X.25Faster alternative to X.25 Internet a small network in 1990Internet a small network in 1990

AcademiaAcademia MilitaryMilitary Some commercial trafficSome commercial traffic

See CUCKOO'S EGG to get a flavorSee CUCKOO'S EGG to get a flavor

Frame Relay Frame Relay

7 Application7 Application 6 Presentation6 Presentation 5 Session 5 Session TCP TCP 4 Transport 4 Transport TCP TCP 3 Network3 Network IPIP 2 Data Link2 Data Link Frame RelayFrame Relay 1 Physical1 Physical

Frame RelayFrame Relay Committed Information Rate (CIR)Committed Information Rate (CIR)

Is a Quality of Service GuaranteeIs a Quality of Service Guarantee"Guaranteed" minimum Bandwidth"Guaranteed" minimum BandwidthShould be set Should be set >> average traffic during average traffic during

appropriate peak periodappropriate peak period Port Connection SpeedPort Connection Speed

a.k.a. Port Speed or Burst Speeda.k.a. Port Speed or Burst SpeedBandwidth you can burst to Bandwidth you can burst to providedprovided

network capacity exists.network capacity exists.Set = Bit Rate of Access LineSet = Bit Rate of Access Line

Frame Relay Packet FormatFrame Relay Packet Format

Data + Padding

3 20 20 up to 8,146 3

IP TCPFR Header

FR Trailer

Header includes 10 bit Data Link Connection Identifier (DLCI) - Locally Unique (FR ports)Trailer includes 2 byte CRC Sequence that only checks HeaderI/O decisions based on FR address & look-up table.