ITNW 1333 -- Microsoft Networking Essentials
Course Syllabus
 
 
 

Chapter 4

Network Interface Cards

 

NIC - Network Interface Card

  • Plugs into adapter slot inside computer
  • NIC = Network interface card
  • Network adapter
  • Network card
 

NIC Basics

  • Creates the network connection
  • Manages the network connection
  • Changes digital data to signal for media
  • Changes signal into data for computer
 

Parallel to Serial & Back

  • Data travels between CPU & adapter in multiple lines on the computer bus (Parallel transmission)
  • Network signal travels over media in a single line (Serial transmission)
  • NICs job is managing this translation
 

Parallel Transmission

  • Multi lane highway in computer
  • Each lane carries part of the traffic
  • At the same time
  • A two-way street
 

Serial Transmission

  • Single lane road on media
  • Single lane carries all of the traffic
  • One direction at a time
  • A one-way street
  • NIC memory stores data in a buffer until conversion
 

Computer Data Bus

  • Collection of parallel lines linking computer components
  • Early computers used 8 bit bus
    • Use 8 lines to move 8 bits at a time
  • Number of lines making up a bus is the Bus width
    • IBM PC/AT (advanced technology)
      • Provided 16 bit bus Industry Standard Architecture
    • ISA 8 & 16 bit bus
    • EISA & MCA 16 & 32 bit bus
    • PCI - Peripheral Component Interface 32 bit bus
 

NIC Transceiver

  • Allows connection to media
  • BNC
  • RJ-45
  • AUI
  • Some NICs have multiple ports
 

NIC Data Packaging

  • Packs bits into packets
  • Handles addressing of data
  • Each NIC has unique network address
  • Media Access Control (MAC)
  • Manages & controls network access
 

PC Busses

 
 

ISA Bus

  • Industry Standard Architecture
  • Original 8 bit bus
  • In 1984 bus became 16 bit
  • 10 MHz top speed
  • Popular for floppy drive, serial ports
 

EISA Bus

  • Extended ISA
  • 32 bit capable
  • EISA slot can handle ISA & EISA cards
  • EISA card has deeper edge connectors
  • Up to 33 MHz
 

MCA Bus

  • Micro Channel Architecture
  • IBM PS/2 computers
  • 16 or 32 bit modes
  • Up to 66 MHz
  • Used in IBM RISC/6000 family
 

PCI Bus

  • Peripheral Component Interface
  • Local bus speed to match CPU
  • 32 bit speed
  • Intel's became the standard
  • Supports Microsoft plug and play
 

Network Interface Card Configuration

 

Principles of NIC Configuration

  • Three basic settings:
    • Interrupt request line (IRQ)
    • Base I/O port
    • Base memory address
  • Configurations
    • Hardware
    • Software
 

Hardware NIC Settings

  • Usually found on older NICs
  • Remove the card to make changes
  • Two ways to configure
    • DIP (dual inline package) switches
    • Jumpers
 

Software Settings

  • Setting IRQs
    • Peripherals signal CPU for attention
    • Each peripheral must have its own IRQ
    • Map machines IRQs using software
    • Microsoft MSD.exe for DOS
    • Microsoft WIN-MSD.exe for Windows
    • See table 4-1 below for common IRQ settings
  • Base I/O Ports
    • Memory area device and CPU use to communicate
    • Dedicated "mailbox" address
    • Each device has its own, unique address
    • Identified by 3 digit hexadecimal #
    • See table 4-2 below for common base I/O port assignments
  • Base Memory Address
    • Memory buffer area for temporary storage
    • Fixed maximum size (extent)
    • Usually in upper memory area or High memory area (HMA)
 
Table 4-1            Common PC IRQs

IRQ

Typical Assignment

0

PC system timer

1

Keyboard

2

Cascading IRQ controller or video adapter

3

Unassigned (used for COM2/COM4 or bus mouse)

4

COM1/COM3

5

Unassigned (used for LPT2, often for sound card)

6

Floppy disk controller

7

Parallel port LPT1

8

Real-time clock

9

Cascading IRQ controller, sometimes sound card

10

Unassigned (used for primary SCSI controller)

11

Unassigned (used for secondary SCSI controller)

12

PS/2 mouse (if none present, unassigned)

13

Math co-processor (if none present, unassigned)

14

Primary hard drive controller, usually IDE (if no IDE drives, unassigned

15

Secondary hard driver controller, usually IDE (if absent, unassigned)
 
Table 4-2            Common NIC base I/O port assignments

Port

Device

Port

Device

200

Game port

300

NIC

210

Unassigned

310

NIC

220

Unassigned

320

Unassigned

230

Bus mouse

330

Unassigned

240

Unassigned

340

Unassigned

250

Unassigned

350

Unassigned

260

Unassigned

360

Unassigned

270

LPT3

370

LPT2

280

NIC

380

Unassigned

290

Unassigned

390

Unassigned

2A0

Unassigned

3A0

Unassigned

2B0

Unassigned

3B0

LPT1

2C0

Unassigned

3C0

EGA/VGA video

2D0

Unassigned

3D0

CGA video

2E0

Unassigned

3E0

Unassigned

2F0

COM2

3F0

COM1, floppy disk controller
 

The Network Attachment

  • Select adapter to match medium
  • Establish a physical link to medium
  • Generate & receive network signals
  • Control when to receive signals
  • Control when to transmit signals
 

Choosing an Adapter

  • Identify physical characteristics
  • Match adapter & connector
  • Server or Client adapter?
  • Consider network applications
  • Consider options for adapter
 

Adapter Enhancements

  • Direct memory access (DMA)
  • Shared adapter memory
  • Shared system memory
  • Bus mastering
  • RAM buffering
  • On-board co-processors
 

Special Purpose NICs

  • Interface for wireless networks
  • Interface for diskless workstations (Thinclient, netpc)
  • Remote boot
  • Remote initial load
 

Remote Boot Adapters

  • Machines start up or "boot" from disk
  • Diskless machines boot off the network
  • Network adapters use boot PROM
  • Programmable Read-Only Memory
 

Driver Software

  • Device driver initializes adapter
  • NDIS - Network device interface specification
  • ODI - Open data-link interface