ECEN 4533 Data Communications Lecture 13 6 February

ECEN 4533 Data Communications Lecture #13 6 February 2013 Dr. George Scheets Read: 2. 4 n Problems: 2. 1, 2. 3, Web 4. 2 n Design #1 due 8 February (Async DL) n u Late = -1 per working day n n Quiz #1 u < 11 February (Async Distance Learning) Corrected quizzes due 13 February (Live)

ECEN 4533 Data Communications Lecture #14 8 February 2013 Dr. George Scheets n n Problems: Web 4, 5, & 6 Design #1 due 8 February (Async DL) u Late = -1 per working day Quiz #1 u < 11 February (Async Distance Learning) u Corrected quizzes due 13 February (Live) Exam #1: 22 February (Live),

Various Protocols n Ethernet u #1 on the wired LAN F Exceptions in some Data Centers u Had plenty of competition 'til mid-90's u Moving into MAN & WAN F LAN n frame is encapsulated Frame Relay u Introduced commercially in 1990 u Has its own Layer 2 Header Format F In early 90's • Ethernet, Token Ring, FDDI common • IP not yet dominant (Novell common)

Various Protocols n ATM u Hot protocol in mid 90's u Complex compared to Frame Relay F Meant to haul all types of traffic F 5 Classes of Service u Derided as too Complex by Internet Fanatics F But now Internet is being asked to move everything F Internet becoming more complex

Various Protocols n Internet u Hot protocol in 2000's u Commodity Internet F Treats all traffic the same u Corporate Internet F Becoming more complex • Diff. Serv: Enables Priorities Not Used on Commodity Internet • Multi-Protocol Label Switching Enables Virtual Circuits

Internet Traffic Growth source: "The Road to 100 G Deployment", IEEE Communications Magazine, March 2010

Internet Traffic source: http: //www. sandvine. coms 2008 - 2009 Comparison

2011 Internet Traffic Profile Source: http: //www. sandvine. com/downloads/documents/ 2011 Global Internet Phenomena Report. pdf

ISP Router Overload Source: 1 October 2007 Network World Fall 2011 Level 3 BGP entries 375, 550 IPv 4 7, 210 IPv 6 Peak Traffic 8. 0 Tbps IPv 4 500 Mbps IPv 6

Router Operates at OSI Layers 1 -3 n Communicate with adjacent Routers n u Exchange "Hello" packets every 10 or so seconds u Exchange Routing info F immediately upon "Hello" failure F general updates several times a day independent of traffic n Use Routing info to generate a Hierarchical Routing Table Example) ISP Backbone Routers Must know how to get to ibm. ucc. okstate. edu Example) OSU Campus Backbone Routers Must know how to get to ibm. ucc. okstate. edu

Switched Ethernet R PC Switched Hub PC Pr Tr PC Acc un PC PC ess L ks Switched Hub PC ines Switched Hub PC PC Packet formatting same as before. Only the Printer will see packets from the PC.

Switched Ethernet PC R PC Pr Switched Hub PC Acc PC PC Tr ess L un PC ks ines Switched Hub PC PC Packets need to cross a network boundary.

Ex) Leased Lines Suppose: *BW available in 64 Kbps chunks (64, 128, 192, 256, 320, 384, 448, etc. ) *Maximum load (traffic/BW) = 50% 320 Kbps Carrier Leased Line Network OKC Traffic Matrix (Bursty Data) From/To OKC DET 256 Kbps Detroit 128 Kbps NYC OKC - 144 76 DET 88 - 28 NYC 112 34 - Router

Ex) Leased Lines Suppose: *BW available in 64 Kbps chunks (64, 128, 192, 256, 320, 384, 448, etc. ) *Maximum load (traffic/BW) = 50% Detroit 384 Kbps Carrier Leased Line Network OKC 320 Kbps From/To OKC DET NYC OKC - 144 76 DET 88 - 28 NYC 112 34 - Router

Ex) Leased Lines with Internet thru OKC Detroit ISP 576 640 Kbps OKC bps K Carrier Leased Line Network 448 K bps NYC From/To OKC DET NYC ISP OKC - 144 76 60 DET 88 - 28 50 NYC 112 34 - 40 ISP 110 100 90 - Router

Ex) Commodity Internet Corporate Connectivity Detroit 384 Kbps OKC 448 Kbps ISP Network 320 Kbps NYC Router From/To OKC DET NYC OKC - 144 76 DET 88 - 28 NYC 112 34 -

Ex) Commodity Internet Corporate & Internet Connectivity Detroit 576 Kbps OKC From/To OKC 640 Kbps Router DET NYC ISP OKC - 144 76 88 - 28 50 NYC 112 34 - ISP 110 100 90 448 Kbps NYC 60 DET ISP Network 320/280 I/O @ OKC → 640 Kbps 40 194/186 I/O @ NYC → 448 Kbps 278/166 I/O @ DET → 576 Kbps -

Virtual Circuit Backbone Server LAN VC #2 PC VC #1 VC Switch Suppose we need to connect to three LAN's. LAN PC

Ex) Frame Relay, ATM, MPLS, Carrier Ethernet Corporate Connectivity Detroit etr D 384 Kbps oit CK , O Carrier Frame Relay, VC P ATM, Ethernet, or MPLS 576 Kbps Internet Network. OKC PVC, N YC - O K From/To OKC DET C 320 Kbps NYC OKC - 144 76 DET 88 - 28 NYC 112 34 - OKC Outbound = 220 +28 +34 Kbps OKC Inbound = 200 + 28 +34 Kbps Leased Line Size > 2*282 = 564 Kbps Leased Line = 576 Kbps minimum.

Ex) Carrier Ethernet, FR, ATM, MPLS Corporate & Internet Connectivity ISP Detroit 576 Kbps t d etroi e siz - D Re C OK 640 Kbps C, Carrier Ethernet, ATM, PV OKC MPLS, or FR Network Router 448 Kbps Resized 960 Kbps NYC PVC, N YC - O From/To OKC DET NYC ISP KC OKC 144 76 60 OKC FR Leased Line must handle DET 88 28 50 NYC & Det traffic ↔ Internet, NYC 112 34 40 OKC ↔ corporate, and ISP 110 100 90 - Detroit/NYC pass-thru traffic.

Leased Line at OKC ↔ FR Net n Outbound u OKC→Det 144 u OKC→NYC 76 u Det→NYC 28 u NYC→Det 34 u ISP→Det 100 u ISP→NYC 90 From/To OKC DET n Inbound u Det→OKC 88 u Det→NYC 28 ISP u Det→ISP 50 u NYC→OKC 112 OKC u NYC→Det 34 u NYC→ISP 40 Detroit NYC ISP OKC - 144 76 60 DET 88 - 28 50 NYC 112 34 - 40 ISP 110 100 90 - Total Outbound = 472 Kbps Total Inbound = 352 Kbps Leased Line Size > 944 Kbps Leased Line = 960 Kbps minimum.

Circuit Switched TDM Leased Line Cross-Connect ? ? 1. 54 Mbps Connections P(Access Line is Active) = 10% 100 Mbps Trunk Bandwidth is assigned based on peak input rates. Can support 64 access lines.

Queue Length 100, 000 bps output trunk n 100, 001 bps average input n Average Input rate > Output rate n Queue Length builds up (without bound, in theory) n

Queue Length 100, 000 bps output trunk n 99, 999 bps average input n Average Input rate < Output rate n Queue Length not infinite. . . but very large n

Queue Length @ 100% Load Output capacity = 7 units Input = 7 units on average (two dice rolled) n n n n n t 1: input = 4, output = 4, queue = 0 t 2: input = 5, output = 5, queue = 0 t 3: input = 4, output = 4, queue = 0 t 4: input = 7, output = 7, queue = 0 t 5: input = 11, output = 7, queue = 4 t 6: input = 10, output = 7, queue = 7 t 7: input = 6, output = 7, queue = 6 t 8: input = 5, output = 7, queue = 4 t 9: input = 8, output = 7, queue = 5 t 10: 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.

Packet Switched Stat. Mux Router or Switch ? ? 1. 54 Mbps Connections P(Access Line is Active) = 10% 100 Mbps Trunk Bandwidth assigned based on average input rates. Can theoretically support 649 access lines. Note if all inputs active, input = 999. 5 Mbps

Probability Density Functions A Histogram is an estimate of the PDF n Important PDF's for Networking n u Gaussian F Very common in the Real World u Binomial F Individual Experiment has 2 states F Experiment results are Independent F Interested in # of successful experiments, not specific order u Exponential F Not a bad model for packet sizes u Poisson

1995 OSU Backbone Packet Histogram Looks somewhat exponential.

2004 OSU Backbone Packet Histogram Still looks sort of exponential, but less so than before,

IM Traffic Message Size

Traffic in 0. 1 second intervals