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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) Outlines Received due 7 October (local) 14 October (remote) 29 % Frame Relay Backbone Frame Aware FR Switch Frame Relay ‘Cloud’ Full Duplex Trunks use StatMux & Packet Switching Frame Relay Format 3 20 20 up to 8,146 3 FR Header IP TCP Data + Padding 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) Line speed of attachment to carrier network For each Virtual Circuit Distance (not all carriers charged for this) CIR (bit rate carrier seeks to guarantee) Full Duplex (same CIR in each direction) Simplex (different CIR's in each direction) Ex) Frame Relay Corporate Connectivity Detroit Carrier Frame Relay Network OKC (Hub) Router Local Carriers dedicate bandwidth to our use. Carrier provides random Packet Switched StatMux connectivity via VC’s. NYC Ex) Frame Relay with Internet Detroit ISP Carrier Frame Relay Network OKC Router Local Carriers dedicate bandwidth to our use. Carrier provides random Packet Switched StatMux connectivity via VC’s. NYC Frame Relay End-to-End Delay Internet ≈ Frame Relay > equivalent sized Leased Line Network Cost Tendency Internet < Frame Relay < equivalent sized Leased Line Network Worldwide Frame Relay Revenues $17B in 2006 Declining. Sources: Data Communications Network World Business Communications Network Strategy Partners Wavesmith Networks U.S. Frame Relay Service Sprint Shut Down Verizon As of 2 January 2009 no new FR customers As of 1 February 2013 Existing customers cannot make changes Existing customers cannot renew service AT&T Still supporting current customers 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 Internet Service Provider Backbone A C ISP Router B ISP ‘Cloud’ Full Duplex Trunks use StatMux & Packet Switching THEN: ISP using Frame Relay VC's for Trunk Connections A C ISP Router FR VC FR Switch Frame Relay ‘Cloud’ B NOW: ISP using Leased Lines for Trunk Connections A C ISP Router Circuit Cross Connect Circuit Switched TDM B NOW: ISP using Light Waves for Trunk Connections A C ISP Router Circuit Optical Switch B Frame Relay Backbone A C FR Switch B THEN: FR using Leased Lines for Trunk Connections A C FR Switch Circuit Cross Connect B NOW: Frame Relay using MPLS VC's for Trunk Connections ISP Router A FR Switch C ISP ‘Cloud’ MPLS VC B Frame Relay as a Corporate Backbone... More Secure than the Commodity Internet Can move a lot of data rapidly (if you pay for proper CIR and burst rate) Is marginal for moving time sensitive traffic Generally Cheaper for data than Leased Lines Fewer access lines required Backbone has higher Carrying Capacity Frame Relay QoS DE bit used by FR switches to police network Traffic > CIR enters switch in a 1 second interval? Marked DE 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. Helps shelter you from behavior of others Commodity Internet Performance Number of dropped packets Average Delay for delivered packets 0% Trunk Offered Load 100% Frame Relay Performance Number of dropped packets* Average Delay for delivered packets 0% Trunk Offered Load 100% *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. Ex) Frame Relay More Secure than Internet Detroit ISP OKC Carrier Frame Company X Relay Network NYC Company X Cannot access us thru FR net. Can get at us thru Internet. Router ATM 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data Link 1 Physical TCP TCP IP ATM ATM Widely deployed in mid-90's Touted as the Network of the Future Chops all traffic into fixed size 53B cells 5B overhead 48B traffic Compromise Data folks wanted larger size Voice folks wanted smaller size ATM Cell Format 5 ATM Header 48 Layer 3-7 information AAL Overhead 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 StatMux ATM Version Different channels use all of the frequency some of the time, at random, as needed. frequency 1 empty (53B slots) 2 1 3 empty 1 Can also use TDM. SWITCHING MULTIPLEXING StatMux TDM X X FDM Circuit Packet Cell ATM uses Cell Switching ATM Used Virtual Circuits No Error Checking of payload Needs fiber on long haul Designed to move all types of traffic Reduces size of physical plant Eases maintenance problems Unless system crashes! Three reasons to consider ATM in the 1990's... Your network is moving mixed traffic You get a good deal $$$$ You need sheer SPEED This was the case on carrier networks ATM on the carrier backbone... Your network is moving mixed traffic yes in 90's (voice & data) not so true in early 00's (data) becoming true in late 00's (data & video) becoming not so true in early 10's (video) You need sheer SPEED yes You in 90's, not true now get a good deal $$$$ competitive in 90's, R&D has stopped ATM Backbone Cell Aware ATM Switch StatMux/TDM, Cell Switched Network, Full Duplex Trunks. ATM at the desktop... Your No. You Moving mostly data. need sheer SPEED No. You network is moving mixed traffic Ethernet is fast enough. get a good deal $$$$ No. Ethernet is cheaper. Virtual Circuit Set Up MPLS, Frame Relay, ATM, Carrier Ethernet Client requests connectivity from Carrier Provides endpoints Specifies Service Level Agreement desired Carrier arranges for connectivity to POP Routing algorithm determines path through network Appropriate Switches Notified Look Up Tables Updated ATM VC Classes of Service Constant Bit Rate (CBR) Leased Line emulation Fixed Rate voice & video Variable Bit Rate- Real Time (VBR-RT) Interactive, variable rate, voice & video Variable Bit Rate- non Real Time (VBR-nRT) Non-Interactive, variable rate, voice & video Available Bit Rate (ABR) Data traffic needing guaranteed bandwidth Unspecified Bit Rate (UBR) Data traffic flying standby ATM VC Classes of Service Cost Hi CBR VBR-RT VBR-nRT ABR UBR Low Delivery Rate Priority Constant Hi Low Variable Delivery Ability to Delay Burst Low None High A Lot The Internet Viewpoint in the 90's ATM's Ability to nail down paths (VC's) Ability to prioritize traffic (5 CoS) Ability to reserve switch resources Trunk BW & Switch Buffer Space Too Complex!! Internet Simpler Treat technique is way to go all traffic the same Today: Internet starting to look a lot like ATM Ability to nail down paths (MPLS) Ability to prioritize traffic (DiffServ) Not used on Commodity Internet Used on carrier VoIP networks Used for some intra-corporate traffic Ability to reserve switch resources Not used on Internet Scalable version of RSVP needed ATM Hookups Customer Viewpoint: WAN see Frame Relay, MPLS Carrier Viewpoint: See Frame Relay, MPLS 2.5 Gbps were fastest trunks available Traffic Policing Somewhat similar to Frame Relay VBR & ABR Cells marked as compliant or not Switch Congested? Drop UBR, then non-compliant VBR & ABR Switched Network Carrying Capacities Carrying Capacity Packet Switch StatMux Cell Switch StatMux Circuit Switch TDM 0% Bursty 100% Fixed Rate Offered Traffic Mix 100% Bursty 0% Fixed Rate OSU Campus Network ('95 - '01) OneNet 802.3 LAN 802.3 LAN 802.3 LAN LAN ATM Switch ATM-Ethernet Switch LAN LAN OSU Campus Network (> 2001) 802.3 LAN Ethernet Switch OneNet 802.3 LAN 802.3 LAN LAN Routers LAN LAN OSU Campus Network (2007) 802.3 LAN Ethernet Switch OneNet 802.3 LAN 802.3 LAN LAN Routers LAN LAN OSU Campus Network (2015) 802.3 LAN Ethernet Switch OneNet 802.3 LAN 802.3 LAN LAN Routers LAN LAN ATM Bombed at the desktop (LAN) Succeeded on the WAN Most Carrier Networks now Decommissioned Still in use on some ADSL access networks Carrier Leased Line Backbone Byte Aware Cross-Connect 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 Network Switches are byte aware I/O decisions on a byte-by-byte basis Could be considered a "Layer 1.5" device Circuit… Dedicated resources Routing thru system determined in advance … is assigned trunk BW via TDM BW required is based on peak input rates Pricing a function of distance & peak rate Internet Service Provider Backbone Packet Aware Router StatMux, Packet Switched Network, Full Duplex Trunks. Access lines mostly attach to corporate routers & routers of other ISP’s. WAN Connectivity Options Internet Switches I/O are packet aware decisions use Layer 3 Internet Protocol address Datagrams Each …are BW packet individually routed assigned trunk BW via StatMux required based more so on average input rates Commodity Internet Pricing … a function of connection size SLA Enabled Internet (Corporate Use) Pricing a function of connection size, MPLS VC (size, DiffServ priority), & maybe distance Frame Relay Backbone FR Frame Aware FR Switch StatMux, Packet Switched Network, Full Duplex Trunks. Access lines mostly attach to routers. WAN Connectivity Options Frame Relay Network Switches I/O are frame aware decisions use Layer 2 Frame Relay address Virtual Circuit… Routing … through system determined in advance is assigned trunk BW via StatMux BW required based more so on average input rates Pricing May Being function of peak rate & CIR be distance independent replaced by Internet & Carrier Ethernet. ATM Backbone Cell Aware ATM Switch StatMux/TDM, Cell Switched Network, Full Duplex Trunks. Replaced by the Internet & Carrier Ethernet. LAN Backbone Ethernet Frame Aware Ethernet Switch StatMux, Packet Switched Network, Full/Half Duplex Trunks. Access lines mostly attach to PC's, servers, & printers. Trunks attach to Ethernet Switches, & routers. Ethernet MAN/WAN 802.3 LAN 802.3 LAN LAN Carrier Ethernet LAN 802.3 LAN Routers Carrier Switches would only see 9 Router MAC addresses LAN LAN Ethernet MAN/WAN 802.3 LAN 802.3 LAN LAN Carrier Ethernet LAN 802.3 LAN LAN LAN Carrier switches would see all PC MAC addresses. Potentially too many! Carrier Ethernet 802.3 LAN 802.3 LAN LAN Carrier Network LAN 802.3 LAN Feed Ethernet Frames to Carrier LAN LAN Carrier Ethernet 802.3 LAN 802.3 LAN LAN Carrier Network LAN 802.3 LAN Feed Ethernet Frames to Carrier LAN LAN Carrier Ethernet 802.3 LAN LAN ISP 802.3 LAN LAN 802.3 LAN Use Internet MPLS VC's Ethernet on Access Lines LAN LAN Carrier Ethernet 802.3 LAN Carrier Ethernet Switches LAN 802.3 LAN LAN 802.3 LAN Use Provider Backbone Bridging Ethernet on access lines. LAN LAN 802.3 Ethernet Packet Format Bytes: 6 MAC Destination Address 6 2 MAC Source Address 20 20 6-1460 4 IP TCP Data + Padding CRC PBB Carrier Ethernet Packet (Simplified) Bytes: 6 6 2 Carrier MAC Carrier Carrier Destination MAC Source VLAN Address Address Tag 6 6 2 MAC MAC Destination Source Address Address 20 20 6-1460 4 IP TCP Data + Padding CRC Carrier Edge switches prepend customer Ethernet frames with provider frames. # Carrier MAC addresses = # Carrier edge switches PBB Carrier Ethernet WAN/MAN LAN LAN LAN LAN Ethernet Switch E1 LAN LAN LAN LAN Every Carrier Switch is an Edge Switch here. LAN Edge Switches learn MAC addresses of serviced end devices. E1 must learn Yellow & Orange MAC & VLAN addresses. PBB Carrier Ethernet Switching (Simplified) Unicast packet arrives with unknown customer destination MAC address Source Carrier Edge Switch Examines Customer VLAN tag & source MAC address Maps to Carrier VLAN tag Carrier Edge Switch MAC address Appends Carrier Header Destination Carrier Edge Switch Examines & Removes Carrier Header Forwards based on Customer MAC address PBB Carrier Ethernet Switching (Simplified) Broadcast packet arrives 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 Destination Carrier Edge Switch(es) Examines & Removes Carrier Header Forwards based on Customer VLAN Carrier Ethernet Status 2009 U.S. Market Revenue $1.5 Billion 2010 $3.2 Billion 2013 $5.5 Billion 2016 $11.1 Billion (projected) 2018 $13 Billion (projected) Backhaul from wireless cell sites a major growth area source: www.accedian.com www.telecompetitor.com MAN/WAN Connectivity Options Carrier Ethernet Carrier Switches are Ethernet frame aware PBB I/O decisions based on Layer 2 Ethernet Address IP/MPLS I/O decisions based on MPLS tag Virtual Circuits can be used StatMux BW required based more so on average input rates Pricing function of peak rate, CIR, priority, and maybe distance On the way in. 21st 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 trunk 100,000,001 bps average input Average Input rate > Output rate Queue Length builds up (without bound, in theory) Queue Length 100,000,000 bps output trunk 99,999,999 bps average input Average Input rate < Output rate Queue Length not infinite... ...but very large Queue Length @ 100% Load Output capacity = 7 units Input = 7 units on average (two dice rolled) t1: input = 4, output = 4, queue = 0 t2: input = 5, output = 5, queue = 0 t3: input = 4, output = 4, queue = 0 t4: input = 7, output = 7, queue = 0 t5: input = 11, output = 7, queue = 4 t6: input = 10, output = 7, queue = 7 t7: input = 6, output = 7, queue = 6 t8: input = 5, output = 7, queue = 4 t9: input = 8, output = 7, queue = 5 t10: input = 11, output = 7, queue = 9 This queue will tend to get very large over time. Queue Length @100% Load Will tend to increase w/o Bound. 34000 3.40910 queue5 j2000 0 0 0 0 2 10 4 10 5 5 6 10 8 10 5 j 5 1 10 6 110 5 6 32000 1.98310 queue5 j1000 0 0 0 0 2 10 5 4 10 5 6 10 5 j 5 8 10 5 1 10 6 110 6 "Die Roll" Queue Lengths 101% Load 34000 3.40910 100% Load queue5 j2000 99% Load, Average Queue = 44.46 0 0 0 0 2 10 5 4 10 5 6 10 5 j 5 8 10 5 1 10 6 110 6 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. Real vs Artificial Trace 100 Seconds Real Traffic 100 Seconds Artificial M/M/1 Traffic Real vs Artificial Trace 16.7 Minutes Real Traffic 16.7 Minutes Artificial M/M/1 Traffic Real vs Artificial Trace 167 Minutes Real Traffic 167 Minutes Artificial M/M/1 Traffic Real vs Artificial Trace 27.78 Hours Real Traffic 27.78 Hours Artificial M/M/1 Traffic Self Similar Behavior Infinite Length Queue (Classical StatMux Theory) Probability of dropped packets Average Delay for delivered packets 0% Trunk Offered Load 100% Finite Length Queue (Real World StatMux) Probability of dropped packets Average Delay for delivered packets 0% Trunk Offered Load 100% You could fully load StatMux trunk lines... but your customers would be screaming at you due to lousy service. 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 Carrying Capacity Line Speed Active Traffic Idle Overhead Carrying Capacity = (%Trunk Load) * (%Traffic) = Traffic(bps)/Line Speed(bps)