Chapter 5: Introducing Network Standards

Lesson 1: Open Systems Interconnection (OSI) Reference Model

This two-part exercise will give you the opportunity to memorize and review the layers of the OSI reference model.

The left column is a listing of a memorization tool: "All People Seem To Need Data Processing." Next to each word in that column, enter the appropriate name of the applicable OSI layer in the center column and a brief description of that layer's function in the right column.

Memorization Tool	OSI Layer	Function
All	Application	Interaction at the user or application level
People	Presentation	Translation of data
Seem	Session	Maintains a session between nodes on a network
To	Transport	Makes sure that transmissions are received
Need	Network	Manages addressing and routing of the packets
Data	Data Link	Physical addressing of packets and error correction
Processing	Physical	Manages the connection to the media

In the second part of Exercise 1 that follows, a device or standard is listed in the left column. In the space provided in the right column, write in the applicable OSI layer(s) for each device or standard.

Device	OSI layer
Gateway	Application-transport layer
NIC	Physical layer
Hub	Physical layer
Router	Network layer
IEEE 802.x	Physical and data-link layers

Lesson 2: The IEEE 802.x Standard

In this exercise, IEEE 802 standards categories are listed in the left column. In the right column, enter a description of what each category represents.

802.x Standard	Basis for standard
802.1	Internetworking
802.2	Logical Link Control (LLC) sublayer
802.3	CSMA/CD Ethernet
802.4	Token Bus LAN
802.5	Token Ring LAN
802.6	Metropolitan Area Networks (MAN)
802.7	Broadband technologies
802.8	Fiber-optic technologies
802.9	Hybrid voice/data networks
802.10	Network security
802.11	Wireless networks
802.12	High-speed LANs
802.13	Unused.
802.14	Defines cable modem standards.
802.15	Defines wireless personal area networks (WPAN).
802.16	Defines broadband wireless standards.

Lesson 3: Device Drivers and OSI

1. Define ODI and describe the role it plays in Novell and Apple NOSs.

The Open Data-Link Interface (ODI) is a specification, developed for Novell and Apple network operating systems (NOSs). It has simplified driver development by allowing multiple protocols, such as IPX/SPX and TCP/IP, working at the data-link layer of the OSI reference model, to share the same NIC or driver. NIC manufacturers can make their boards work with Apple and Novell NOSs by supplying ODI-compliant software drivers.

2. Printer manufacturers are responsible for writing _______________ for their printer products.

drivers

3. Drivers described in an operating system manufacturer's ________ have been tested and included with their operating system.

HCL

4. NIC drivers reside on the computer's _________ _________.

hard disk

5. Protocol drivers use an _________ interface to communicate with the NICs.

NDIS

6. Translation software is required to _____________ ________________ NDIS and ODI.

bridge between

1. The OSI reference model divides network activity into ____________ layers.

seven

2. The purpose of each layer is to provide services to the next _____________ layer and shield the upper layer from the details of how the services are actually implemented.

higher

3. At each layer, the software adds some additional formatting or _________________ to the packet.

addressing

4. Each layer on one computer appears to communicate directly with the ___________ layer on another computer.

same

5. The top, or ___________________, layer handles general network access, flow control, and error recovery.

application

6. At the sending computer, the _____________________ layer translates data from a format sent down from the application layer.

presentation

7. The ________________ layer determines the route from the source to the destination computer.

network

8. The data-link layer is responsible for sending __________ ___________ from the network layer to the physical layer.

data frames

9. The ________________ information in a data frame is used for frame type, routing, and segmentation information.

control

10. The __________________ layer defines how the cable is attached to the�NIC.

physical

11. Windows NT groups the seven OSI layers into three. The three NT layers are ________ ____________ ___________, ____________ _______________, and ________ _____________.

file system drivers, transport protocols, and NIC drivers.

12. An _________ provides the interface between the Windows NT applications and file system drivers layer.

API

13. A _________ provides the interface between the Windows NT file system drivers layer and the transport protocols.

TDI

14. An _________ provides the interface between the Windows NT, the transport protocols layer, and the NIC drivers.

NDIS

15. The Project 802 specifications define the way __________ access and transfer data over physical media.

NICs

16. The 802 project divided the __________ - __________ layer of the OSI reference model into two sublayers, the Logical Link Control (LLC) layer and the Media Access Control (MAC) layer.

data-link

17. The _________ sublayer communicates directly with the NIC and is responsible for delivering error-free data between two computers on the network.

MAC

18. The IEEE category __________ covers LAN standards for Ethernet.

802.3

19. The IEEE category __________ covers LAN standards for Token Ring.

802.5

20. A driver is _______________ that enables a computer to work with a device.

software

21. NICs work in the _________ sublayer of the __________ -_________ layer of the OSI model.

MAC, data-link

22. NDIS defines an interface for communication between the __________ sublayer and the protocol drivers.

MAC

23. NDIS was jointly developed by ___________________ and ____________.

Microsoft, 3Com

24. ODI works just like NDIS but was developed by ______________ and ________________ for interfacing hardware to their protocols.

Apple, Novell