OutlinesReceived

due 13 March

OutlinesReceived

due 13 March24 %

HomeworkHomework Review for Midterm on 1 March 2000Review for Midterm on 1 March 2000 Research PaperResearch Paper ReadingsReadings

[11] “ATM Systems: What’s Next?”[11] “ATM Systems: What’s Next?”[12] “Long Distance LAN[12] “Long Distance LAN

Interconnectivity”Interconnectivity”

MID-TERMMID-TERM 1 Hour 15 minute Test 1 Hour 15 minute Test Practice LAN/MAN problems on the WebPractice LAN/MAN problems on the Web Work 4 of 5 pagesWork 4 of 5 pages Know the last midterm, 7 Layer ModelKnow the last midterm, 7 Layer Model Memory Dump in the space providedMemory Dump in the space provided Calculators are NOT allowedCalculators are NOT allowed

...Set up numerical problem for full credit...Set up numerical problem for full credit

IP over Frame RelayIP over Frame Relay

7 Application7 Application 6 Presentation6 Presentation 5 Session TCP5 Session TCP 4 Transport TCP4 Transport TCP 3 Network3 Network IPIP 2 Data Link2 Data Link Frame Relay Frame Relay 1 Physical1 Physical

Internet Service Provider BackboneInternet Service Provider Backbone

If you look closely atthe Router Trunks, you may find they are...

Router

TrunksLeased Line

Frame Relay is an ISP favoriteFrame Relay is an ISP favorite

... Frame Relay Virtual Circuits.

FR Switch

Trunks

ISP Router

Leased Line

FRPVC

Frame Relay as a Corporate Backbone...

Frame Relay as a Corporate Backbone...

More Secure than the InternetMore Secure than the 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

ATMATM OSI Layer 2 ProtocolOSI Layer 2 Protocol Uses Cell SwitchingUses Cell Switching

5 bytes overhead, 48 bytes traffic5 bytes overhead, 48 bytes traffic Capable of hauling all types of trafficCapable of hauling all types of traffic

(voice, data, & video) (voice, data, & video) Works at any speed, any distanceWorks at any speed, any distance Uses Virtual CircuitsUses Virtual Circuits

ATMis a

Compromise

ATMis a

Compromise

Consider ATM if...Consider ATM if...

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

Connection RelationshipsConnection Relationships Virtual Channel: Virtual Channel:

Individual Service Component. Individual Service Component. Smallest switchable unit.Smallest switchable unit.

Virtual Path: Virtual Path: Group of Virtual Channels with sameGroup of Virtual Channels with same

endpoints & QoS requirementsendpoints & QoS requirements Backbone ATM switches: Switch VP’sBackbone ATM switches: Switch VP’s Edge ATM switches: Edge ATM switches:

Switch VC’s and VP’sSwitch VC’s and VP’s

Selected ATM ParametersSelected ATM Parameters

PCR: Peak Cell RatePCR: Peak Cell RateMaximum submission rateMaximum submission rate

SCR: Sustainable Cell RateSCR: Sustainable Cell RateAverage sustainable submission rateAverage sustainable submission rate

MCR: Minimum Cell RateMCR: Minimum Cell RateGuaranteed minimum delivery rateGuaranteed minimum delivery rate

CDV: Cell Delay VariabtionCDV: Cell Delay VariabtionVariability in cell inter-arrival timesVariability in cell inter-arrival times

ATM Classes of ServiceATM Classes of Service

Constant Bit Rate (CBR)Constant Bit Rate (CBR)Circuit Switched EmulationCircuit Switched Emulation Fixed rate voice or video Fixed rate voice or video

(compressed or uncompressed)(compressed or uncompressed) Leased LinesLeased Lines

Key Parameters: PCR & CDV (small)Key Parameters: PCR & CDV (small)

ATM Classes of ServiceATM Classes of Service

Variable Bit Rate - Real Time (VBR-RT)Variable Bit Rate - Real Time (VBR-RT)Interactive variable rate compressed Interactive variable rate compressed voice or videovoice or video TelephonyTelephony VideoconferencingVideoconferencing

Key Parameters: PCR, SCR, CDV (larger)Key Parameters: PCR, SCR, CDV (larger)

ATM Classes of ServiceATM Classes of Service

Variable Bit Rate - Non Real Time (VBR-NRT)Variable Bit Rate - Non Real Time (VBR-NRT)Non-interactive variable rate compressed voice Non-interactive variable rate compressed voice

or videoor video Broadcast RadioBroadcast Radio Broadcast TVBroadcast TV Could, and has been, used instead of ABR VC’sCould, and has been, used instead of ABR VC’s

Key Parameters: PCR, SCRKey Parameters: PCR, SCR

ATM Classes of ServiceATM Classes of Service Available Bit Rate (ABR)Available Bit Rate (ABR)

Data traffic needing some guaranteesData traffic needing some guarantees Interactive data trafficInteractive data traffic Frame Relay or ISP TrunksFrame Relay or ISP Trunks

Key Parameters: PCR & MCRKey Parameters: PCR & MCRFeedback Loop: Available bandwidthFeedback Loop: Available bandwidth

adjusts to network conditions.adjusts to network conditions.MCR < Available Bandwidth < PCRMCR < Available Bandwidth < PCR

ATM Classes of ServiceATM Classes of Service

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

Key Parameter: PCRKey Parameter: PCR

ATM BackboneATM Backbone

ATM ‘Cloud’ Trunks use StatMux & Cell Switching CBR trunk traffic may use TDM & Cell Switching

ATM SwitchATM Switch

TrunksLeased Line

ATM Call Admission ControlATM Call Admission Control

Procedure for setting up SVC’s & PVC’s Procedure for setting up SVC’s & PVC’s End user requests call set-upEnd user requests call set-up

Provides destination, CoS, parametersProvides destination, CoS, parameters Switches determine if resourses areSwitches determine if resourses are

availableavailableSufficient Buffer Space?Sufficient Buffer Space?Sufficient unreserved trunk bandwidth?Sufficient unreserved trunk bandwidth?

Call is rejected if insufficient resourcesCall is rejected if insufficient resources

ATMATM

Hookups:Hookups:WAN see Frame RelayWAN see Frame RelayMAN see OSU BackboneMAN see OSU BackboneLAN see Switched EthernetLAN see Switched Ethernet

Performance:Performance:Depends on the Class of ServiceDepends on the Class of Service

ATM PerformanceATM Performance

0% 100%Trunk Offered Load

Probability of dropped cells

*Provided we are following traffic contract

UBR

ABR*VBR-nrt* & VBR-rt*

CBR

ATM PerformanceATM Performance

0% 100%Trunk Offered Load

Delays of delivered cells

*Provided we are following traffic contract

UBRABR*VBR-nrt* & VBR-rt*

CBR

Switched Network Carrying CapacitiesSwitched Network Carrying Capacities

0% Data 100% Data100% TST 0% TST

Offered Load

Carrying Capacity

Circuit Switch TDM

Packet Switch StatMux

Cell Switch StatMux

ATM StatusATM Status is flunking at the desktopis flunking at the desktop

Mixed Traffic? NoMixed Traffic? No Speed Advantage? NoSpeed Advantage? No $$$ savings? No$$$ savings? No PC protocols can’t handle QoSPC protocols can’t handle QoS

is succeeding on Carrier Backbonesis succeeding on Carrier Backbones Mixed Traffic? YesMixed Traffic? Yes Speed Advantage? No (at the moment)Speed Advantage? No (at the moment) $$$ savings? Competitive$$$ savings? Competitive

U.S. ATM WAN RevenuesU.S. ATM WAN Revenues

$0.0

1B ‘9

4$0

.03B

‘95

$0.0

6B ‘9

6$.

16B ‘9

7$0

.38B

‘98

$0.0

0B ‘9

3

$0.7

2B ‘9

9

Source:Data Communications

About 3-4 yearsbehind Frame

Carrier BackboneCarrier Backbone ATM SwitchATM Switch

Trunks

Carrier FrameCarrier Frame Relay Switch Relay Switch

Leased Line

ISP Router

Private ATM ‘Edge’ Switch

Carrier Voice Switch

ATM Backbone Carrying Mixed Traffic.Trunks are more effectively utilized.ATM Backbone Carrying Mixed Traffic.Trunks are more effectively utilized.

Frame Relay BackboneFrame Relay Backbone

A close look at the FRTrunks may reveal that...

FR Switch

TrunksLeased Line

Frame Relay over ATMFrame Relay over ATM

Carrier BackboneCarrier Backbone ATM SwitchATM Switch

Trunks

Carrier FrameCarrier Frame Relay Switch Relay Switch

Leased Line

ATMPVC

ISP Router...they are actually ATMVirtual Circuits.

Frame Relay over ATM Frame Relay over ATM

7 Application7 Application 6 Presentation6 Presentation 5 Session TCP5 Session TCP 4 Transport TCP4 Transport TCP 3 Network3 Network IPIP 2 Data Link 2 Data Link Frame Relay/ATMFrame Relay/ATM 1 Physical1 Physical