Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann ITL Basics of Encoding and Wiring

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Objectives  Quick overview of wide-area communications  Define the term “Structured Wiring”  Define "analog" and "digital" data.  List the common methods used to encode analog/digital data using analog/digital signaling.  Discuss transmission media and wiring system standards

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Wide-Area Data Communication Nomenclature DTEDCE Wide Area Network Short- Distance Connection Data Consumer or Local Area Network Router Workstation Server/Mainframe RS-232 V.35 RS449/530 HSSI Modem CSU/DSU DS-0 ISDN DS-1 DS3 OC1 OC3 OC12

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann RS232-C Connections DTEDCE Protective Ground TD (Transmit Data) RD (Receive Data) RTS (Request to Send) CTS (Clear to Send) DSR (Data Set Ready) Signal Ground CD (Carrier Detect) RD (Ring Detect) DTR (Data Terminal Ready)

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Transmission Media  Guided Media – Twisted Pair – Coaxial Cable – Optical Fiber  Unguided Media – “Broadcast”-type radio transmission » Wireless LANs, Cell Phones, PCS – Satellite – Point-to-Point Microwave

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Transmission Systems  Basic multiplexing – DS-n (T1, DS3) – SONET (OC-3, OC-12, etc) – WDM  Multiplexing and Other Functions – Ethernet – Frame Relay – ATM

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Structured Wiring  Main Cross-Connect (Main Distribution Frame) – Riser Cable(“Backbone”)  Intermediate Cross-Connect (Int. Dist. Frame) – Horizontal Wiring  Jack Field – Drop Cable  Workstation

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Why use Hierarchical Wiring?  Flexibility = Lower Cost From Bates, Voice and Data Communications Handbook: – Estimated Cost for 50 single wire pulls: $15,568 – Estimated Cost for 50 dual wire pulls: $16,935

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Wiring Standards  Building Wiring Standards – Electronic Industries Association – Telecommunications Industry Association – EIA/TIA 568 Commercial Building Wiring Standard  “Outside Plant” – Bell Labs technical publications – Now maintained by Telcordia (formerly Bellcore)

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann RJ-What?  As an aside for the eternally curious: The RJxx nomenclature appears in the legal documents used by the FCC to identify permitted methods to connect telecom equipment to the network  For the really, really curious: Title 47 CFR, Part 68, Subpart F, Section 502

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Signal Transmission Overview Analog Data over Analog Transmission Systems Digital Data over Analog Transmission Systems Analog Data over Digital Transmission Systems Digital Data over Digital Transmission Systems

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Analog Signaling of Digital Data  Encode "0" and "1" as changes in one signal property  Amplitude Shift Keying: Use two signal amplitudes, one for each bit value.  Frequency Shift Keying: Change the signal frequency to indicate the bit value.  Phase Shift Keying: Create a phase change relative to the most recent bit to indicate the bit value

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Digital Signaling of Analog Information  Voice Codec – Pulse Code Modulation (PCM) – Compressed Voice  Video Codec

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Digital Encoding Example PCM  Example: Voice  4000 Hz  Sample at twice the highest frequency (8000 samples per second)  8 bits per sample  Result: 64kbps

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Digital Signaling Digital Data Encoding Schemes:  NRZ  Manchester  Differential Manchester  Bipolar - AMI

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Digital Signaling of Digital Data Manchester Code Every bit position has a transition (clocking) Signal has no DC component Transition Direction Encodes the Data Used in Ethernet

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Bipolar AMI Coding Used in T1 Signaling

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Levels (Wiring) and Categories (System Performance) Level/CAT 11Mbps Level/ CAT 24Mbps Level/ CAT 316Mbps Level/ CAT 420Mbps Level/ CAT 5100Mbps 1000 Mbps (4 pair) 100m max distance Level/ CAT 5E100Mbps 1000 Mbps (4 pair) Level/ CAT MHzNot yet a standard

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Cable standards versus system performance Source:

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Applications Source: Lucent Technologies

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Ethernet  Designed as a broadcast medium; each transmission is received by every station  Based on a bus architecture  Manchester Encoding  Several Media Types – 10Base5 – 10Base2 – 10Base-T – 10Base-F

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann 10Base-T  Simulates the Ethernet bus using an active star topology.  Uses unshielded twisted pair wiring.  “4-pair” (8 conductor) wiring is normally used, but only 2 pairs are used – 1 transmit pair one receive pair  Each station connects to a central hub. – Cables are wired “straight through” – Hub ports are “crossed” (transmit/receive are reversed

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Fast Ethernet  All use a star topology  100Base-TX – Two pair copper wire (Cat 5) – Same pin-out at 10Base-T, better wire  100Base-FX – Two fibers  100Base-T4 – Rarely used; 4 pair lower quality (cat 3) wires  1000Base-X (4 pair Cat 5 or 5E)

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann FDDI  100 Mbps Ring  Usually based on optical fiber  Based on the Token Ring Standard  Provides capacity pre-allocation  Economics: – Ethernet is cheaper than token ring and does almost as good a job – so it wins – Fast Ethernet is cheaper than FDDI and does almost as good a job – so it wins

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Other Stuff  The slides after this one have probably not been used in class unless a specific question came up

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Phase and Amplitude Shift Keying Example: Eight Levels degrees normal amplitude 180 degrees double amplitude

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Digital Signaling of Digital Data NRZ-L coding (Non-Return to Zero, Level) Multiple bits may be sent without a transition Signal has a DC component Example: RS-232 uses +3V for "0" and -3V for "1"

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Digital Signaling of Digital Data NRZI coding (Invert on One) Multiple bits may be sent without a transition Signal has a DC component Polarity insensitive, partially self-timing Example: ISDN

Applied Data Networking © 2003, Hans Kruse and Shawn Ostermann Digital Signaling of Digital Data Differential Manchester Code Every bit position has a transition (clocking) Signal has no DC component and is polarity - neutral Differential Signal provides some error detection