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ECEN5553 Telecom Systems Dr. George Scheets Week #7 Read [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)
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Outlines Received due 7 October (local) 14 October (remote) 29 %
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Frame Relay Backbone Frame Relay ‘Cloud’ Full Duplex Trunks use StatMux & Packet Switching FR Switch Trunks Leased Line Frame Aware
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Frame Relay Format Data + Padding 3 20 20 up to 8,146 3 IPTCP FR 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.
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Frame Relay Customer Cost n Port Speed (a.k.a. Port Connection Speed) u Line speed of attachment to carrier network n For each Virtual Circuit u Distance (not all carriers charged for this) u CIR (bit rate carrier seeks to guarantee) F Full Duplex (same CIR in each direction) F Simplex (different CIR's in each direction)
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Ex) Frame Relay Corporate Connectivity OKC (Hub) Detroit NYC Carrier Frame Relay Network VC, OKC - Detroit VC, NYC - OKC Router Local Carriers dedicate bandwidth to our use. Carrier provides random Packet Switched StatMux connectivity via VC’s.
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Ex) Frame Relay with Internet Detroit NYC Carrier Frame Relay Network VC, OKC - Detroit VC, NYC - OKC Router Local Carriers dedicate bandwidth to our use. Carrier provides random Packet Switched StatMux connectivity via VC’s. ISP OKC
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Frame Relay n End-to-End Delay Internet ≈ Frame Relay > equivalent sized Leased Line Network n Cost Tendency Internet < Frame Relay < equivalent sized Leased Line Network
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Sources: Data Communications Network World Business Communications Network Strategy Partners Wavesmith Networks $17B in 2006 $0.23B ‘94$0.65B ‘95 $1.28B ‘96 $3.87B ‘97 $6.25B ‘98 $0.08B ‘93 $8.00B ‘99 $10.5B ‘00 $12.7B ‘01 $15.4B ‘02 $16.7B ‘03 Worldwide Frame Relay Revenues $21B ‘04 Declining.
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U.S. Frame Relay Service n Sprint u Shut Down n Verizon u As of 2 January 2009 no new FR customers u As of 1 February 2013 Existing customers cannot make changes Existing customers cannot renew service n AT&T u Still supporting current customers u Turning off system 30 April 2016 Source: http://www.verizonenterprise.com/external/service_guide/reg/cp_frame_relay.htm & http://techcaliber.com/blog/?p=1100
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Internet Service Provider Backbone A C B ISP ‘Cloud’ Full Duplex Trunks use StatMux & Packet Switching ISP Router Trunks Leased Line
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THEN: ISP using Frame Relay VC's for Trunk Connections Frame Relay ‘Cloud’ A C FR Switch FR Trunks Leased Line ISP Trunk FR VC B ISP Router
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NOW: ISP using Leased Lines for Trunk Connections A C Cross Connect Circuit Switched TDM Trunks ISP Router Leased Line ISP Trunk Circuit B
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NOW: ISP using Light Waves for Trunk Connections A C Optical Switch Trunks Fiber Optics ISP Trunk Circuit B ISP Router
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Frame Relay Backbone A C B FR Switch Trunks Leased Line
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THEN: FR using Leased Lines for Trunk Connections A C Cross Connect Trunks FR Switch Leased Line ISP Trunk Circuit B
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NOW: Frame Relay using MPLS VC's for Trunk Connections ISP ‘Cloud’ A C FR Switch ISP Trunks ISP Router Leased Line FR Trunk MPLS VC B
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Frame Relay as a Corporate Backbone... n More Secure than the Commodity Internet n Can move a lot of data rapidly (if you pay for proper CIR and burst rate) n Is marginal for moving time sensitive traffic n Generally Cheaper for data than Leased Lines Fewer access lines required Backbone has higher Carrying Capacity
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Frame Relay QoS n DE bit used by FR switches to police network n Traffic > CIR enters switch in a 1 second interval? Marked DE n If you are behaving......and other users exceed their CIR’s......and FR switch becomes congested......then other users’ traffic gets dumped 1st......your traffic is protected. n Helps shelter you from behavior of others
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Commodity Internet Performance 0% 100% Trunk Offered Load Number of dropped packets Average Delay for delivered packets
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Frame Relay Performance 0% 100% Trunk Offered Load Number of dropped packets* Average Delay for delivered 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.
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OKC Detroit NYC PVC, OKC - Detroit PVC, NYC - OKC Router ISP Ex) Frame Relay More Secure than Internet Company X Cannot access us thru FR net. Company X Carrier Frame Relay Network Can get at us thru Internet.
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ATM n 7 Application n 6 Presentation n 5 Session TCP n 4 Transport TCP n 3 Network IP n 2 Data Link ATM n 1 Physical
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ATM n Widely deployed in mid-90's u Touted as the Network of the Future n Chops all traffic into fixed size 53B cells u 5B overhead u 48B traffic n Compromise u Data folks wanted larger size u Voice folks wanted smaller size
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ATM Cell Format 5 48 ATM Header Carrier ATM Core Header includes: 28 Bits of Addressing Information 3 Bit Payload Type (Priorities) 1 Bit Cell Loss Priority (similar to FR DE bit) 8 Bits Header Error Control Layer 3-7 information AAL Overhead
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StatMux ATM Version frequency time 1 1 3 1 Different channels use all of the frequency some of the time, at random, as needed. empty (53B slots) empty Can also use TDM. 2
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StatMuxTDMFDM Circuit Packet Cell MULTIPLEXING SWITCHING ATM uses Cell Switching X X
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ATM n Used Virtual Circuits n No Error Checking of payload u Needs fiber on long haul n Designed to move all types of traffic u Reduces size of physical plant u Eases maintenance problems Unless system crashes!
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Three reasons to consider ATM in the 1990's... n Your network is moving mixed traffic n You get a good deal $$$$ n You need sheer SPEED n This was the case on carrier networks
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ATM on the carrier backbone... Your network is moving mixed traffic yes in 90's (voice & data) not so true in early 00's (data) becoming true in late 00's (data & video) becoming not so true in early 10's (video) You need sheer SPEED yes in 90's, not true now You get a good deal $$$$ competitive in 90's, R&D has stopped
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ATM Backbone ATM Switch Trunks Leased Line Cell Aware StatMux/TDM, Cell Switched Network, Full Duplex Trunks.
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ATM at the desktop... Your network is moving mixed traffic No. Moving mostly data. You need sheer SPEED No. Ethernet is fast enough. You get a good deal $$$$ No. Ethernet is cheaper.
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Virtual Circuit Set Up MPLS, Frame Relay, ATM, Carrier Ethernet n Client requests connectivity from Carrier u Provides endpoints u Specifies Service Level Agreement desired n Carrier arranges for connectivity to POP n Routing algorithm determines path through network u Appropriate Switches Notified u Look Up Tables Updated
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ATM VC Classes of Service n Constant Bit Rate (CBR) u Leased Line emulation u Fixed Rate voice & video n Variable Bit Rate- Real Time (VBR-RT) u Interactive, variable rate, voice & video n Variable Bit Rate- non Real Time (VBR-nRT) u Non-Interactive, variable rate, voice & video n Available Bit Rate (ABR) u Data traffic needing guaranteed bandwidth n Unspecified Bit Rate (UBR) u Data traffic flying standby
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ATM VC Classes of Service n CBR n VBR-RT n VBR-nRT n ABR n UBR Cost Hi Low Priority Hi Low Delivery Rate Constant Variable Delivery Delay Low High Ability to Burst None A Lot
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The Internet Viewpoint in the 90's n ATM's u Ability to nail down paths (VC's) u Ability to prioritize traffic (5 CoS) u Ability to reserve switch resources F Trunk BW & Switch Buffer Space n Too Complex!! n Internet u Simpler technique is way to go F Treat all traffic the same
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Today: Internet starting to look a lot like ATM n Ability to nail down paths (MPLS) n Ability to prioritize traffic (DiffServ) u Not used on Commodity Internet u Used on carrier VoIP networks u Used for some intra-corporate traffic n Ability to reserve switch resources u Not used on Internet u Scalable version of RSVP needed
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ATM Hookups ATM Hookups nCnCnCnCustomer Viewpoint: WAN see Frame Relay, MPLS nCnCnCnCarrier Viewpoint: uSuSuSuSee Frame Relay, MPLS u2u2u2u2.5 Gbps were fastest trunks available nTnTnTnTraffic Policing uSuSuSuSomewhat similar to Frame Relay uVuVuVuVBR & ABR Cells marked as compliant or not uSuSuSuSwitch Congested? Drop UBR, then non-compliant VBR & ABR
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Switched Network Carrying Capacities 0% Bursty 100% Bursty 100% Fixed Rate 0% Fixed Rate Offered Traffic Mix Carrying Capacity Circuit Switch TDM Packet Switch StatMux Cell Switch StatMux
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802.3 LAN OSU Campus Network ('95 - '01) ATM Switch OC-3, then OC-12 Trunks OneNet ATM-EthernetSwitch 802.3 LAN 802.3 LAN
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802.3 LAN OSU Campus Network (> 2001) Routers 1 Gbps Ethernet OneNet EthernetSwitch 802.3 LAN 802.3 LAN
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802.3 LAN OSU Campus Network (2007) Routers 1 &10 Gbps Ethernet OneNet EthernetSwitch 802.3 LAN 802.3 LAN
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802.3 LAN OSU Campus Network (2015) Routers 10 & 20 Gbps Ethernet OneNet EthernetSwitch 802.3 LAN 802.3 LAN
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ATM n Bombed at the desktop (LAN) n Succeeded on the WAN n Most Carrier Networks now Decommissioned n Still in use on some ADSL access networks RIP
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Carrier Leased Line Backbone Cross-Connect Trunks Leased Line Byte Aware TDM, Circuit Switched Network, Full Duplex Trunks. Access lines mostly attach to routers, FR switches, TD Muxes, & cross connects of other carriers.
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WAN Connectivity Options n Leased Line Network u Switches are byte aware F I/O decisions on a byte-by-byte basis F Could be considered a "Layer 1.5" device u Circuit… F Dedicated resources F Routing thru system determined in advance u … is assigned trunk BW via TDM F BW required is based on peak input rates u Pricing a function of distance & peak rate
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Internet Service Provider Backbone Router Trunks Leased Line Packet Aware StatMux, Packet Switched Network, Full Duplex Trunks. Access lines mostly attach to corporate routers & routers of other ISP’s.
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WAN Connectivity Options n Internet u Switches are packet aware F I/O decisions use Layer 3 Internet Protocol address u Datagrams … F Each packet individually routed u …are assigned trunk BW via StatMux F BW required based more so on average input rates n Commodity Internet u Pricing a function of connection size n SLA Enabled Internet (Corporate Use) u Pricing a function of connection size, MPLS VC (size, DiffServ priority), & maybe distance
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Frame Relay Backbone FR Switch Trunks Leased Line FR Frame Aware StatMux, Packet Switched Network, Full Duplex Trunks. Access lines mostly attach to routers.
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WAN Connectivity Options n Frame Relay Network u Switches are frame aware F I/O decisions use Layer 2 Frame Relay address u Virtual Circuit… F Routing through system determined in advance u … is assigned trunk BW via StatMux F BW required based more so on average input rates u Pricing function of peak rate & CIR F May be distance independent u Being replaced by Internet & Carrier Ethernet.
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ATM Backbone ATM Switch Trunks Leased Line Cell Aware StatMux/TDM, Cell Switched Network, Full Duplex Trunks. Replaced by the Internet & Carrier Ethernet.
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LAN Backbone Ethernet Switch Trunks Access Line Ethernet Frame Aware StatMux, Packet Switched Network, Full/Half Duplex Trunks. Access lines mostly attach to PC's, servers, & printers. Trunks attach to Ethernet Switches, & routers.
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802.3 LAN Ethernet MAN/WAN Routers CarrierEthernet 802.3 LAN 802.3 LAN n Carrier Switches would only see 9 Router MAC addresses
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802.3 LAN Ethernet MAN/WAN 802.3 LAN 802.3 LAN n Carrier switches would see all PC MAC addresses. Potentially too many! CarrierEthernet
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802.3 LAN Carrier Ethernet 802.3 LAN 802.3 LAN n Feed Ethernet Frames to Carrier CarrierNetwork
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802.3 LAN Carrier Ethernet 802.3 LAN 802.3 LAN CarrierNetwork n Feed Ethernet Frames to Carrier
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802.3 LAN Carrier Ethernet 802.3 LAN 802.3 LAN n Use Internet MPLS VC's Ethernet on Access Lines ISP
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802.3 LAN Carrier Ethernet 802.3 LAN 802.3 LAN n Use Provider Backbone Bridging Ethernet on access lines. CarrierEthernetSwitches
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802.3 Ethernet Packet Format MAC Destination Address MAC Source Address CRCData + Padding Bytes: 6 6 2 20 20 6-1460 4 IPTCP
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PBB Carrier Ethernet Packet (Simplified) MAC Destination Address MAC Source Address CRCData + Padding Bytes: 6 6 2 6 6 2 20 20 6-1460 4 IPTCP Carrier MAC Destination Address Carrier MAC Source Address n Carrier Edge switches prepend customer Ethernet frames with provider frames. u # Carrier MAC addresses = # Carrier edge switches Carrier VLAN Tag
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LAN PBB Carrier Ethernet WAN/MAN E1 EthernetSwitch LAN Every Carrier Switch is an Edge Switch here. Edge Switches learn MAC addresses of serviced end devices. E1 must learn Yellow & Orange MAC & VLAN addresses. LAN
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PBB Carrier Ethernet Switching (Simplified) n Unicast packet arrives with unknown customer destination MAC address u Source Carrier Edge Switch Examines Customer VLAN tag & source MAC address Maps to Carrier VLAN tag Carrier Edge Switch MAC address Appends Carrier Header u Destination Carrier Edge Switch Examines & Removes Carrier Header Forwards based on Customer MAC address
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PBB Carrier Ethernet Switching (Simplified) n Broadcast packet arrives u Source Carrier Edge Switch Examines Customer VLAN tag & source MAC address Maps to Carrier VLAN tag Carrier Edge Switch MAC address(es) Appends Carrier Header Selectively Floods u Destination Carrier Edge Switch(es) Examines & Removes Carrier Header Forwards based on Customer VLAN
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Carrier Ethernet Status n 2009 U.S. Market Revenue $1.5 Billion u 2010 $3.2 Billion u 2013 $5.5 Billion u 2016 $11.1 Billion (projected) u 2018 $13 Billion (projected) n Backhaul from wireless cell sites a major growth area source: www.accedian.com www.telecompetitor.com
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MAN/WAN Connectivity Options n Carrier Ethernet u Carrier Switches are Ethernet frame aware F PBB I/O decisions based on Layer 2 Ethernet Address F IP/MPLS I/O decisions based on MPLS tag u Virtual Circuits can be used u StatMux F BW required based more so on average input rates u Pricing function of peak rate, CIR, priority, and maybe distance u On the way in. F 21st century version of Frame Relay
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Carrying Capacity Line Speed Active Idle Application Traffic Overhead Carrying Capacity = Traffic(bps)/Line Speed(bps) Goodput = Application Traffic Carried (bps)
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Queue Length n 100,000,000 bps output trunk n 100,000,001 bps average input n Average Input rate > Output rate n Queue Length builds up (without bound, in theory)
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Queue Length n 100,000,000 bps output trunk n 99,999,999 bps average input n Average Input rate < Output rate n Queue Length not infinite......but very large
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Queue Length @ 100% Load Output capacity = 7 units Input = 7 units on average (two dice rolled) n t1: input = 4, output = 4, queue = 0 n t2: input = 5, output = 5, queue = 0 n t3: input = 4, output = 4, queue = 0 n t4: input = 7, output = 7, queue = 0 n t5: input = 11, output = 7, queue = 4 n t6: input = 10, output = 7, queue = 7 n t7: input = 6, output = 7, queue = 6 n t8: input = 5, output = 7, queue = 4 n t9: input = 8, output = 7, queue = 5 n t10: input = 11, output = 7, queue = 9 This queue will tend to get very large over time.
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Queue Length @100% Load Will tend to increase w/o Bound.
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"Die Roll" Queue Lengths 100% Load 101% Load 99% Load, Average Queue = 44.46
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Real vs Artificial Trace 10 Seconds Real Traffic 10 Seconds Artificial M/M/1 Traffic Source: Willinger et al, "Self-Similarity through High Variability", IEEE/ACM Transactions on Networking, February 1997.
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Real vs Artificial Trace 100 Seconds Real Traffic 100 Seconds Artificial M/M/1 Traffic
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Real vs Artificial Trace 16.7 Minutes Real Traffic 16.7 Minutes Artificial M/M/1 Traffic
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Real vs Artificial Trace 167 Minutes Real Traffic 167 Minutes Artificial M/M/1 Traffic
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Real vs Artificial Trace 27.78 Hours Real Traffic 27.78 Hours Artificial M/M/1 Traffic
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Self Similar Behavior
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Infinite Length Queue (Classical StatMux Theory) 0% 100% Trunk Offered Load Probability of dropped packets Average Delay for delivered packets
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Finite Length Queue (Real World StatMux) 0% 100% Trunk Offered Load Probability of dropped packets Average Delay for delivered packets Classical Self-Similar You could fully load StatMux trunk lines... but your customers would be screaming at you due to lousy service.
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Switched Network Carrying Capacity Line Speed: Traffic injection speed Efficiency: Ability to use that Line Speed Throughput: bps of traffic (+ overhead) moved = Efficiency * Line Speed Carrying Capacity: Ability to usefully use Line Speed Accounts for packet overhead Accounts for inability to fully load trunk lines with StatMux'd traffic & still have a usable connection Goodput: bps of application traffic moved = Carrying Capacity * Line Speed
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Carrying Capacity Line Speed Active Idle Traffic Overhead Carrying Capacity = (%Trunk Load) * (%Traffic) = Traffic(bps)/Line Speed(bps)
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