ecen5553 telecom systems dr. george scheets week #7 read [14a] ipv6: a catalyst and evasion tool for...
DESCRIPTION
Frame Relay Backbone Frame Relay ‘Cloud’ Full Duplex Trunks use StatMux & Packet Switching FR Switch Trunks Leased Line Frame AwareTRANSCRIPT
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)