Basics of Communications

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Basics of Communications
Presented By Patrick Bolwahnn
April 14, 2005
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Today

• Session Objectives
• Learning and Understanding the Basics of Reader
  Communication
• Innovation
• Terminology
• Infrastructure Considerations
• Equipment and Devices
• Results
• The ability to understand and deploy a well
  designed reader network.

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WT Background

• Installed January 1998
• Wired February 1998
• Recarded Fall of 1998
• Services Offered
• Copy, Laundry, Vending, Bookstore
• Point of Sale, Activity Validation
• 120 Locations

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WT Background

• FY 2003-2004
• 9000 Active Cardholders
• 1.5 Million in Deposits
• Meal Plans 300k
• Book Loans 350k
• Flexible Spending 850K
• 220 On-Campus Locations and 35 Off-Campus
  Locations
• Door Access

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Terminology

• Network Processor - Transaction Approval
• Application Processor - Long Term Storage, DB
• Reader Networks Communications Devices,
  Wiring and Readers
• Locations - Location Number a Reader is Assigned
• Loop - Physical Wire
• Addresses - numbers 0-15 assigned to reader

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Terminology

• Modems communication device (RS232)
• Converters Converts from one protocol to
  another.
• IP Communications Communicating over a Data
  Network
• RS232
• RS485

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Terminology

• Do you have to be a wiring expert?

• NoJust need to know enough to make good
  decisions

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Installation Considerations

• AP/NP Location
• Number Size of Buildings
• Number Readers in each building
• Cable topology fiber, copper
• Network Strategy and Support
• Data Network
• Separate Reader Network / VLAN
• Power connections
• Shelf/rack space

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WTAMU Communications

• Remote Line Driver loops
• IPC loops
• 1 IPC Loops
• 25 Active Loops
• 24 Remotes Loop
• 2 RF Loops
• 265 Locations

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Reader Networks

• Consists of
• Network Processor
• Communications Devices
• Cabling
• Readers
• Cabling and Communication Devices make up the
  three basic reader loops
• Local
• Remote
• IP Network

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Network Processor

• Network Processors communicates with each reader
  on the network and processes their
  transactions.
• NPs Communicationis handled through
• CP16 Panels
• Mux Panel
• LAN Cards

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Local Loops

• Local loops are generally within the same
  building as the NP. Local loops can be
  accomplished two ways.
• Use CP8 boards which have some RS-485 converters
  built in.
• CP16 boards do not have converters
• NP cable to RS 485 converter

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Remote loops

• A Remote Loop is any loop that services a remote
  building(s) or remote campuses. This can be
  accomplished through many combinations of
  devices.
• Devices Types
• Terminal Servers(TS) via a Data Network or
  Internet
• Line Drivers
• RS 485 converters.
• IP Converters
• IP Readers

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Communications Protocols

• Protocols are like different languages. Some
  protocols the BTSUE system uses to communicate
  are
• RS 485
• Allows multiple units to communicate over the
  same wire. ( 5 pin)
• RS 232
• Basic data communication used in PC and device
  communication, 1 1 ( 3 pin)
• TCP/IP
• Standard Networking protocol which Terminal
  servers, IP Converters, IP readers utilize on
  a data network.

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Standard Communications

• Line Drivers
• Short haul modems less than 2 miles
• Long distance modems more than 2 miles
• Types of medium
• Fiber
• Copper
• Uses Standard RS 232 protocol (3 pin)

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Standard Communications

• Special devices
• Multiplexer
• Loop Splitters

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Standard Communications

• RS 485 Converters
• Design to convert RS 232 to 485 protocol
• Has 1x10 jack to connect local readercable
  network

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Standard Communications
Building A
Computer Center
NP
Line Driver
Line Driver
Reader
485
Line Driver
Loop Spliter
Line Driver
Building B
Line Driver
Building C
Line Driver
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IP Communications

• Terminal Servers
• Designed to Convert RS232 to TCP/IP and back
  again.
• IP Converters
• Design to convert TCP/IP to RS 485 protocol
• IP enabled Readers VR/MDB2

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IP Communications
First IP Communications devices were terminal
servers
NP
Terminal Server
Data Network
Terminal Server
RS 485
Reader
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IP Communications

• IP Converters
• Design to convert TCP/IP to RS 485 protocol

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IP Communications
NP
Data Network
IP Converter
IP Reader
RS 485
Reader
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Other Communication Methods

• Radio Frequency
• Blackbox RF-115 modem
• 900 Mhz RS232 protocol
• Range up to 20 mileswith repeaters

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Wiring

• Supported wiring
• Belden 8723
• 2 pair with shield
• Use T568b wall plate with screw lugsor DB 15
• Cat 5 10base-T (most common installation)
• Twisted Pair Network Cabling
• Use T568b RJ45 standard network jack

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Pros for communication types
IP - easiest/quickest to install, or move -Easy
to diagnose communication problems??? -Comes back
on-line fairly quickly, when the network is out
-Could be used over the Internet to connect
remote campuses
Local Loops Lower cost no LD or TS. -Fast
response times. -Independent wiring not
attached to net.
Line Driver -Fast Response times. -Independent
wiring - not attached to data network. -Slightly
Cheaper than TS. -Supported by Blackboard -Simple
- No Configuration neededAlways up! -Works with
Copper and Fiber lines -Easy to troubleshoot
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Cons for communication types
IP -Network Outage -Denial of Service -Firewall
and VLANs can block communication if not
configured right. -Depends highly on
relation-ship with IT
Local Loops -Difficult to move server.
Line Driver -Difficult to move server. -Copper
needs optical isolation - Cost of running wiring
if not available
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Security Issues with IPC

• IPCs Communicate with the NP with 128bit
  Blowfish encryption.
• No problems so far with denial of service
  attacks.
• Downstream communication between IPC and Reader
  is still vulnerable.
• Having the IPC on a VLAN and behind a firewall
  greatly increases security.

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Recap

• Installation Considerations
• AP/NP Location
• Number Size of Buildings
• Number Readers in each building
• Cable topology fiber, copper
• Network Strategy and Support
• Data Network
• Separate Reader Network / VLAN
• Power connections
• Shelf/rack space

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• Links
• Behind the Blackboard
• System Implementation Guidehttp//www.blackboard.
  com/docs//h931431.pdf
• Follow up Contact InformationPbolwahnn_at_mail.wtamu
  .edu
• If you remember one thingThere are many options
  for deploying your reader network