ECEN5553 Telecom SystemsDr. George Scheets Week #7Read[14a] "IPv6: A Catalyst and Evasion Tool for Botnets"[14b] "Segmenting for security"[15a] "All Quiet on the Internet Front"[15b] "DARPA: Nobody's Safe on the Internet"[17a] "Rapidly Recovering from the Catastrophic

Loss of a Major Telecommunications Office"[17b] "How IT Leaders Can Best Plan For

Disaster"

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

OutlinesReceived

due 7 October (local)14 October (remote)

29 %

Frame Relay Backbone

Frame Relay ‘Cloud’ Full Duplex Trunks use StatMux & Packet Switching

FR Switch

TrunksLeased LineFrameAware

Frame Relay Format

Data + Padding

3 20 20 up to 8,146 3

IP TCPFR Header

FR Trailer

I/O Decision based on DLCI & Look-up Table.Header & Trailer usually swapped out.

Look Up Table Format:DLCI ww received on port x?

Output on port y with DLCI zz.

Frame Relay Customer Cost

Port Speed (a.k.a. Port Connection Speed)Port Speed (a.k.a. Port Connection Speed) Line speed of attachment to carrier networkLine speed of attachment to carrier network

For each Virtual CircuitFor each Virtual Circuit Distance (not all carriers charged for this)Distance (not all carriers charged for this) CIR (bit rate carrier seeks to guarantee)CIR (bit rate carrier seeks to guarantee)

Full Duplex (same CIR in each direction)Full Duplex (same CIR in each direction) Simplex (different CIR's in each direction)Simplex (different CIR's in each direction)

Ex) Frame RelayCorporate Connectivity

OKC(Hub)

Detroit

NYC

Carrier FrameRelay Network

VC, OKC - Detroit

VC, NYC - OKCRouter

Local Carriers dedicate bandwidth to our use. Carrier provides random Packet Switched StatMux connectivity via VC’s.

Ex) Frame Relay with InternetDetroit

NYC

Carrier FrameRelay Network

VC, OKC - Detroit

VC, NYC - OKCRouter

Local Carriers dedicate bandwidth to our use. Carrier provides random Packet Switched StatMux connectivity via VC’s.

ISP

OKC

Frame Relay End-to-End DelayEnd-to-End Delay

Internet ≈ Internet ≈ Frame Relay > Frame Relay > equivalent sized Leased equivalent sized Leased Line Network Line Network

Cost TendencyCost TendencyInternet < Internet < Frame Relay < Frame Relay < equivalent sized Leased equivalent sized Leased Line Network Line Network

Sources:Data CommunicationsNetwork World Business CommunicationsNetwork Strategy PartnersWavesmith Networks

$17B in 2006

$0.23

B ‘9

4$0

.65B

‘95

$1.28

B ‘9

6$3

.87B

‘97

$6.25

B ‘9

8

$0.08

B ‘9

3

$8.00

B ‘9

9$1

0.5B

‘00

$12.7

B ‘0

1$1

5.4B

‘02

$16.7

B ‘0

3

Worldwide Frame Relay Revenues

$21B

‘04

Declining.

U.S. Frame Relay Service SprintSprint

Shut DownShut Down VerizonVerizon

As of 2 January 2009 no new FR customersAs of 2 January 2009 no new FR customers As of 1 February 2013As of 1 February 2013

Existing customers cannot make changesExisting customers cannot make changesExisting customers cannot renew serviceExisting customers cannot renew service

AT&TAT&T Still supporting current customersStill supporting current customers Turning off system 30 April 2016Turning off system 30 April 2016

Source: http://www.verizonenterprise.com/external/service_guide/reg/cp_frame_relay.htm & http://techcaliber.com/blog/?p=1100

Internet Service Provider Backbone

A

C B

ISP ‘Cloud’Full Duplex Trunks use StatMux & Packet Switching

ISP Router

TrunksLeased Line

THEN: ISP using Frame Relay VC's for Trunk Connections

Frame Relay ‘Cloud’

A

C

FR Switch

FR TrunksLeased LineISP Trunk

FRVC

B

ISPRouter

NOW: ISP using Leased Linesfor Trunk Connections

A

C

Cross ConnectCircuit SwitchedTDM

TrunksISP

RouterLeased LineISP Trunk

Circuit

B

NOW: ISP using Light Wavesfor Trunk Connections

A

C

Optical Switch

TrunksFiber OpticsISP Trunk

Circuit

B

ISPRouter

Frame Relay Backbone

A

C B

FR Switch

TrunksLeased Line

THEN: FR using Leased Linesfor Trunk Connections

A

C

Cross Connect

Trunks

FR Switch

Leased LineISP Trunk

Circuit

B

NOW: Frame Relay using MPLS VC's for Trunk

Connections

ISP ‘Cloud’

A

CFR Switch

ISP Trunks

ISP Router

Leased LineFR Trunk

MPLSVC

B

Frame Relay as a Corporate Backbone...

More Secure than the Commodity InternetMore Secure than the Commodity Internet Can move a lot of data rapidly Can move a lot of data rapidly

(if you pay for proper CIR and burst rate)(if you pay for proper CIR and burst rate) Is marginal for moving time sensitive trafficIs marginal for moving time sensitive traffic Generally Cheaper for data than Leased LinesGenerally Cheaper for data than Leased Lines

Fewer access lines required Fewer access lines required Backbone has higher Carrying Capacity Backbone has higher Carrying Capacity

Frame Relay QoS DE bit used by FR switches to police networkDE bit used by FR switches to police network Traffic > CIR enters switch in a 1 second interval? Traffic > CIR enters switch in a 1 second interval?

Marked DEMarked DE If you are behaving...If you are behaving...

...and other users exceed their CIR’s......and other users exceed their CIR’s...

...and FR switch becomes congested......and FR switch becomes congested...

...then other users’ traffic gets dumped 1st......then other users’ traffic gets dumped 1st...

...your traffic is protected....your traffic is protected. Helps shelter you from behavior of othersHelps shelter you from behavior of others

Commodity Internet Performance

0% 100%Trunk Offered Load

Number of dropped packets

Average Delay fordelivered packets

Frame Relay Performance

0% 100%Trunk Offered Load

Number of dropped packets*

Average Delay fordelivered packets

*Dashed: If we are transmitting at > CIR Solid: Provided we are transmitting at < CIR Some protection from behavior of others. Internet priorities provide somewhat similar effect.

OKC

Detroit

NYC

PVC, OKC - D

etroit

PVC, NYC - OKC

Router

ISP

Ex) Frame RelayMore Secure than Internet

Company XCannot access us thru FR net.

Company XCarrier FrameRelay Network

Can get at us thru Internet.

ATM

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 ATMATM 1 Physical1 Physical

ATM Widely deployed in mid-90'sWidely deployed in mid-90's

Touted as the Network of the FutureTouted as the Network of the Future Chops all traffic into fixed size 53B cellsChops all traffic into fixed size 53B cells

5B overhead5B overhead 48B traffic48B traffic

CompromiseCompromise Data folks wanted larger sizeData folks wanted larger size Voice folks wanted smaller sizeVoice folks wanted smaller size

ATM Cell Format5 48

ATM Header

Carrier ATM Core Header includes:28 Bits of Addressing Information3 Bit Payload Type (Priorities)1 Bit Cell Loss Priority (similar to FR DE bit)8 Bits Header Error Control

Layer 3-7 informationAAL Overhead

StatMuxATM Version

frequency

time

1

13

1

Different channels use all of the frequency some of the time,at random, as needed.

empty (53B slots)

empty

Canalsouse

TDM.

2

StatMux TDM FDM

Circuit

Packet

Cell

MULTIPLEXINGSW

ITC

HIN

G

ATM uses Cell Switching

XX

ATM Used Virtual CircuitsUsed Virtual Circuits No Error Checking of payloadNo Error Checking of payload

Needs fiber on long haulNeeds fiber on long haul Designed to move all types of trafficDesigned to move all types of traffic

Reduces size of physical plantReduces size of physical plant Eases maintenance problemsEases maintenance problems

Unless system crashes!

Three reasons to consider ATM in the 1990's...

Your network is moving mixed trafficYour network is moving mixed traffic You get a good deal $$$$ You get a good deal $$$$ You need sheer SPEEDYou need sheer SPEED

This was the case on carrier networksThis was the case on carrier networks

ATM on the carrier backbone... Your network is moving mixed trafficYour network is moving mixed traffic

yes in 90's (voice & data)yes in 90's (voice & data) not so true in early 00's (data)not so true in early 00's (data) becoming true in late 00's (data & video)becoming true in late 00's (data & video) becoming not so true in early 10's (video) becoming not so true in early 10's (video)

You need sheer SPEEDYou need sheer SPEED yes in 90's, not true now yes in 90's, not true now

You get a good deal $$$$You get a good deal $$$$ competitive in 90's, R&D has stoppedcompetitive in 90's, R&D has stopped

ATM Backbone

ATM SwitchATM Switch

TrunksLeased LineCell

Aware

StatMux/TDM, Cell Switched Network, Full Duplex Trunks.

ATM at the desktop...

Your network is moving mixed trafficYour network is moving mixed traffic No. Moving mostly data.No. Moving mostly data.

You need sheer SPEEDYou need sheer SPEED No. Ethernet is fast enough.No. Ethernet is fast enough.

You get a good deal $$$$You get a good deal $$$$ No. Ethernet is cheaper.No. Ethernet is cheaper.

Virtual Circuit Set UpMPLS, Frame Relay, ATM,

Carrier Ethernet Client requests connectivity from CarrierClient requests connectivity from Carrier

Provides endpointsProvides endpoints Specifies Service Level Agreement desiredSpecifies Service Level Agreement desired

Carrier arranges for connectivity to POPCarrier arranges for connectivity to POP Routing algorithm determines path through networkRouting algorithm determines path through network

Appropriate Switches NotifiedAppropriate Switches Notified Look Up Tables Updated Look Up Tables Updated

ATM VC Classes of Service Constant Bit Rate (CBR)Constant Bit Rate (CBR)

Leased Line emulationLeased Line emulation Fixed Rate voice & videoFixed Rate voice & video

Variable Bit Rate- Real Time (VBR-RT)Variable Bit Rate- Real Time (VBR-RT) Interactive, variable rate, voice & videoInteractive, variable rate, voice & video

Variable Bit Rate- non Real Time (VBR-nRT)Variable Bit Rate- non Real Time (VBR-nRT) Non-Interactive, variable rate, voice & videoNon-Interactive, variable rate, voice & video

Available Bit Rate (ABR)Available Bit Rate (ABR) Data traffic needing guaranteed bandwidth Data traffic needing guaranteed bandwidth

Unspecified Bit Rate (UBR)Unspecified Bit Rate (UBR) Data traffic flying standbyData traffic flying standby

ATM VC Classes of Service

CBR CBR VBR-RTVBR-RTVBR-nRTVBR-nRTABRABRUBRUBR

CostHi

Low

PriorityHi

Low

DeliveryRate

Constant

Variable

DeliveryDelayLow

High

Ability to BurstNone

A Lot

The Internet Viewpoint in the 90's ATM'sATM's

Ability to nail down paths (VC's)Ability to nail down paths (VC's) Ability to prioritize traffic (5 CoS)Ability to prioritize traffic (5 CoS) Ability to reserve switch resourcesAbility to reserve switch resources

Trunk BW & Switch Buffer SpaceTrunk BW & Switch Buffer Space Too Complex!!Too Complex!! InternetInternet

Simpler technique is way to goSimpler technique is way to go Treat all traffic the sameTreat all traffic the same

Today: Internet starting to look a lot like ATM

Ability to nail down paths (MPLS)Ability to nail down paths (MPLS) Ability to prioritize traffic (DiffServ)Ability to prioritize traffic (DiffServ)

Not used on Commodity InternetNot used on Commodity Internet Used on carrier VoIP networksUsed on carrier VoIP networks Used for some intra-corporate trafficUsed for some intra-corporate traffic

Ability to reserve switch resourcesAbility to reserve switch resources Not used on InternetNot used on Internet Scalable version of RSVP neededScalable version of RSVP needed

ATM Hookups Customer Viewpoint:Customer Viewpoint:

WAN see Frame Relay, MPLSWAN see Frame Relay, MPLS Carrier Viewpoint: Carrier Viewpoint:

See Frame Relay, MPLSSee Frame Relay, MPLS 2.5 Gbps were fastest trunks available2.5 Gbps were fastest trunks available

Traffic PolicingTraffic Policing Somewhat similar to Frame RelaySomewhat similar to Frame Relay VBR & ABR Cells marked as compliant or notVBR & ABR Cells marked as compliant or not Switch Congested? Drop UBR, thenSwitch Congested? Drop UBR, then

non-compliant VBR & ABRnon-compliant VBR & ABR

Switched Network Carrying Capacities

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

Traffic Mix

Carrying Capacity

Circuit Switch TDM

Packet Switch StatMuxCell Switch StatMux

802.3LAN

LAN

OSU Campus Network ('95 - '01)

ATM SwitchATM Switch

OC-3, thenOC-12Trunks

OneNet

ATM-EthernetATM-EthernetSwitchSwitch

802.3LAN

802.3LAN

LAN

LAN

802.3LAN

LAN

OSU Campus Network (> 2001)

RoutersRouters

1 GbpsEthernet

OneNetEthernetEthernetSwitchSwitch

802.3LAN

802.3LAN

LAN

LAN

802.3LAN

LAN

OSU Campus Network (2007)

RoutersRouters

1 &10 GbpsEthernet

OneNetEthernetEthernetSwitchSwitch

802.3LAN

802.3LAN

LAN

LAN

802.3LAN

LAN

OSU Campus Network (2015)

RoutersRouters

10 & 20 GbpsEthernet

OneNetEthernetEthernetSwitchSwitch

802.3LAN

802.3LAN

LAN

LAN

ATM

Bombed at the desktop (LAN)Bombed at the desktop (LAN) Succeeded on the WANSucceeded on the WAN Most Carrier Networks now Most Carrier Networks now

DecommissionedDecommissioned

Still in use on some ADSL access networksStill in use on some ADSL access networks

RIP

Carrier Leased Line Backbone

Cross-ConnectCross-Connect

TrunksLeased LineByte

Aware

TDM, Circuit Switched Network, Full Duplex Trunks.Access lines mostly attach to routers, FR

switches, TD Muxes, & cross connects of other carriers.

WAN Connectivity Options Leased Line NetworkLeased Line Network

Switches are byte awareSwitches are byte aware I/O decisions on a byte-by-byte basisI/O decisions on a byte-by-byte basis Could be considered a "Layer 1.5" deviceCould be considered a "Layer 1.5" device

Circuit…Circuit… Dedicated resourcesDedicated resources Routing thru system determined in advanceRouting thru system determined in advance

… … is assigned trunk BW via TDMis assigned trunk BW via TDM BW required is based on BW required is based on peakpeak input rates input rates

Pricing a function of distance & peak ratePricing a function of distance & peak rate

Internet Service Provider Backbone

Router

TrunksLeased LinePacketAware

StatMux, Packet Switched Network, Full Duplex Trunks.Access lines mostly attach to corporate routers

& routers of other ISP’s.

WAN Connectivity Options InternetInternet

Switches are packet awareSwitches are packet aware I/O decisions use Layer 3 Internet Protocol addressI/O decisions use Layer 3 Internet Protocol address

Datagrams …Datagrams … Each packet individually routed Each packet individually routed

……are assigned trunk BW via StatMuxare assigned trunk BW via StatMux BW required based more so on BW required based more so on averageaverage input rates input rates

Commodity InternetCommodity Internet Pricing a function of connection sizePricing a function of connection size

SLA Enabled InternetSLA Enabled Internet (Corporate Use) (Corporate Use) Pricing a function of connection size, MPLS VC (size, Pricing a function of connection size, MPLS VC (size,

DiffServ priority), & maybe distanceDiffServ priority), & maybe distance

Frame Relay Backbone

FR Switch

TrunksLeased LineFR Frame

Aware

StatMux, Packet Switched Network, Full Duplex Trunks.Access lines mostly attach to routers.

WAN Connectivity Options Frame Relay NetworkFrame Relay Network

Switches are frame awareSwitches are frame aware I/O decisions use Layer 2 Frame Relay addressI/O decisions use Layer 2 Frame Relay address

Virtual Circuit…Virtual Circuit… Routing through system determined in advanceRouting through system determined in advance

… … is assigned trunk BW via StatMuxis assigned trunk BW via StatMux BW required based more so on BW required based more so on averageaverage input rates input rates

Pricing function of peak rate & CIRPricing function of peak rate & CIR May be distance independentMay be distance independent

Being replaced by Internet & Carrier Ethernet.Being replaced by Internet & Carrier Ethernet.

ATM Backbone

ATM SwitchATM Switch

TrunksLeased LineCell

Aware

StatMux/TDM, Cell Switched Network, Full Duplex Trunks.Replaced by the Internet & Carrier Ethernet.

LAN Backbone

Ethernet SwitchEthernet Switch

TrunksAccess Line

EthernetFrameAware

StatMux, Packet Switched Network, Full/Half Duplex Trunks.Access lines mostly attach to PC's, servers, & printers.

Trunks attach to Ethernet Switches, & routers.

802.3LAN

LAN

Ethernet MAN/WAN

RoutersRouters

CarrierCarrierEthernetEthernet802.3

LAN

802.3LAN

LAN

LAN

LAN

Carrier Switches would only Carrier Switches would only see 9 Router MAC addressessee 9 Router MAC addresses

802.3LAN

LAN

Ethernet MAN/WAN

802.3LAN

802.3LAN

LAN

LAN

LAN

Carrier switches would see all Carrier switches would see all PC MAC addresses. Potentially too many!PC MAC addresses. Potentially too many!

CarrierCarrierEthernetEthernet

802.3LAN

LAN

Carrier Ethernet

802.3LAN

802.3LAN

LAN

LAN

LAN

Feed Ethernet Frames to CarrierFeed Ethernet Frames to Carrier

CarrierCarrierNetworkNetwork

802.3LAN

LAN

Carrier Ethernet

802.3LAN

802.3LAN

LAN

LAN

LAN

CarrierCarrierNetworkNetwork

Feed Ethernet Frames to CarrierFeed Ethernet Frames to Carrier

802.3LAN

LAN

Carrier Ethernet

802.3LAN

802.3LAN

LAN

LAN

LAN

Use Internet MPLS VC'sUse Internet MPLS VC'sEthernet on Access LinesEthernet on Access Lines

ISPISP

802.3LAN

LAN

Carrier Ethernet

802.3LAN

802.3LAN

LAN

LAN

LAN

Use Provider Backbone BridgingUse Provider Backbone BridgingEthernet on access lines.Ethernet on access lines.

CarrierCarrierEthernetEthernetSwitchesSwitches

802.3 Ethernet Packet Format

MACDestination

Address

MACSource

Address

CRCData + Padding

Bytes: 6 6 2

20 20 6-1460 4

IP TCP

PBB Carrier Ethernet Packet (Simplified)

MACDestination

Address

MACSource

Address

CRCData + Padding

Bytes: 6 6 2 6 6 2

20 20 6-1460 4

IP TCP

Carrier MACDestination

Address

Carrier MAC Source

Address

Carrier Edge switches prepend customer Ethernet frames with Carrier Edge switches prepend customer Ethernet frames with provider frames.provider frames. # Carrier MAC addresses = # Carrier edge switches# Carrier MAC addresses = # Carrier edge switches

Carrier VLAN

Tag

LAN

LAN

PBB Carrier Ethernet WAN/MAN

E1

EthernetEthernetSwitchSwitch

LANLAN

LAN

LAN

Every Carrier Switch is an Edge Switch here. Every Carrier Switch is an Edge Switch here. Edge Switches learn MAC addresses of serviced end devices. E1 Edge Switches learn MAC addresses of serviced end devices. E1

must learn must learn YellowYellow & & OrangeOrange MAC & VLAN addresses. MAC & VLAN addresses.

LAN

LAN

LAN

PBB Carrier Ethernet Switching (Simplified) Unicast packet arrives with unknown customer Unicast packet arrives with unknown customer

destination MAC addressdestination MAC address Source Carrier Edge SwitchSource Carrier Edge Switch

ExaminesExamines Customer VLAN tag & source MAC address Customer VLAN tag & source MAC address Maps toMaps toCarrier VLAN tag Carrier VLAN tag Carrier Edge Switch MAC addressCarrier Edge Switch MAC addressAppendsAppends Carrier Header Carrier Header

Destination Carrier Edge SwitchDestination Carrier Edge SwitchExamines & Removes Examines & Removes Carrier HeaderCarrier HeaderForwardsForwards based on Customer MAC address based on Customer MAC address

PBB Carrier Ethernet Switching (Simplified) Broadcast packet arrivesBroadcast packet arrives

Source Carrier Edge SwitchSource Carrier Edge SwitchExaminesExamines Customer VLAN tag & source MAC address Customer VLAN tag & source MAC address Maps toMaps toCarrier VLAN tag Carrier VLAN tag Carrier Edge Switch MAC address(es)Carrier Edge Switch MAC address(es)AppendsAppends Carrier Header Carrier HeaderSelectively FloodsSelectively Floods

Destination Carrier Edge Switch(es)Destination Carrier Edge Switch(es)Examines & Removes Examines & Removes Carrier HeaderCarrier HeaderForwardsForwards based on Customer VLAN based on Customer VLAN

Carrier Ethernet Status

2009 U.S. Market Revenue $1.5 Billion2009 U.S. Market Revenue $1.5 Billion 2010 $3.2 Billion2010 $3.2 Billion 2013 $5.5 Billion2013 $5.5 Billion 2016 $11.1 Billion (projected)2016 $11.1 Billion (projected) 2018 $13 Billion (projected)2018 $13 Billion (projected)

Backhaul from wireless cell sites a major growth Backhaul from wireless cell sites a major growth areaarea

source: www.accedian.comwww.telecompetitor.com

MAN/WAN Connectivity Options Carrier EthernetCarrier Ethernet

Carrier Switches are Ethernet frame awareCarrier Switches are Ethernet frame aware PBB I/O decisions based on Layer 2 Ethernet AddressPBB I/O decisions based on Layer 2 Ethernet Address IP/MPLS I/O decisions based on MPLS tagIP/MPLS I/O decisions based on MPLS tag

Virtual Circuits can be usedVirtual Circuits can be used StatMuxStatMux

BW required based more so on BW required based more so on averageaverage input rates input rates Pricing function of peak rate, CIR, priority, and maybe distancePricing function of peak rate, CIR, priority, and maybe distance On the way in.On the way in.

21st century version of Frame Relay21st century version of Frame Relay

Carrying Capacity

Line Speed

Active Idle

Application Traffic Overhead

Carrying Capacity = Traffic(bps)/Line Speed(bps)

Goodput = Application Traffic Carried (bps)

Queue 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 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) 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.

0 2 105 4 105 6 105 8 105 1 1060

2000

40003.409 103

0

queue5 j

1 1060 j 5

0 2 105 4 105 6 105 8 105 1 1060

1000

20001.983 103

0

queue5 j

1 1060 j 5

"Die Roll" Queue Lengths

0 2 105 4 105 6 105 8 105 1 1060

2000

40003.409 103

0

queue5 j

1 1060 j 5

100% Load

101% Load

99% Load, Average Queue = 44.46

Real vs Artificial Trace

10 SecondsReal Traffic 10 Seconds

Artificial M/M/1 TrafficSource: Willinger et al, "Self-Similarity through High Variability", IEEE/ACM Transactions on Networking, February 1997.

Real vs Artificial Trace

100 SecondsReal Traffic 100 Seconds

Artificial M/M/1 Traffic

Real vs Artificial Trace

16.7 MinutesReal Traffic 16.7 Minutes

Artificial M/M/1 Traffic

Real vs Artificial Trace

167 MinutesReal Traffic 167 Minutes

Artificial M/M/1 Traffic

Real vs Artificial Trace

27.78 HoursReal Traffic 27.78 Hours

Artificial M/M/1 Traffic

Self Similar Behavior

Infinite Length Queue (Classical StatMux Theory)

0% 100%Trunk Offered Load

Probability of dropped packets

Average Delay fordelivered packets

Finite Length Queue (Real World StatMux)

0% 100%Trunk Offered Load

Probability of dropped packets

Average Delay fordelivered packets C

lass

ical

Self-

Sim

ilar

You could fully load StatMux trunk lines... but yourcustomers would be screaming at you due to lousy service.

Switched Network Carrying Capacity

Line SpeedLine Speed: Traffic injection speed: Traffic injection speed EfficiencyEfficiency: Ability to use that Line Speed: Ability to use that Line Speed ThroughputThroughput: bps of traffic (+ overhead) moved: bps of traffic (+ overhead) moved

= Efficiency * Line Speed= Efficiency * Line Speed Carrying CapacityCarrying Capacity: Ability to : Ability to usefullyusefully use Line Speed use Line Speed

Accounts for packet overheadAccounts for packet overhead Accounts for inability to fully load trunk lines with Accounts for inability to fully load trunk lines with

StatMux'd traffic & still have a usable connectionStatMux'd traffic & still have a usable connection Goodput: Goodput: bps of application traffic movedbps of application traffic moved

= Carrying Capacity * Line Speed= Carrying Capacity * Line Speed

Carrying Capacity

Line Speed

Active Idle

Traffic Overhead

Carrying Capacity = (%Trunk Load) * (%Traffic) = Traffic(bps)/Line Speed(bps)