Chapter 3: Understanding Network Architecture

Lesson 5: AppleTalk and ArcNet

1. What kind of network should they install?

Server-based ____

Peer-to-peer ____

A server-based network is suggested because the number of workstations (34), when combined, exceeds the recommended limit of 10 for a peer-to-peer network. Also, because this company uses a variety of computers (PCs and Macintoshes), it will be easier to implement the server-based network. By getting all the computers standardized and networked, this company is moving toward a more centralized administration. Installing the server-based network now will put them well on their way to a more centralized system and open to future expansion. A peer-to-peer network at this time would limit future expansion. Because the company needs a server-based operating system that serves both Macintoshes and personal computers, you could choose Microsoft Windows NT Server, although there are several other server-based operating systems, such as Netware, that could complete the same functions.

2. What type of network should the company implement within the offices?

Fiber-optic Ethernet ____

Fiber-optic Token Ring ____

Fiber-optic ArcNet ____

Ethernet 10BaseT ____

Ethernet 10Base2 ____

Token Ring ____

LocalTalk ____

ArcNet ____

Within the offices, Ethernet 10BaseT is the suggested solution because it is supported on all platforms and is easy to troubleshoot and install. Token Ring and ArcNet solutions would also work, but LocalTalk would not meet the requirements because:

• It is slow.
• It is difficult to find LocalTalk cards for personal computers.

3. What type of network should the company install between the two buildings?

Fiber-optic Ethernet ____

Fiber-optic Token Ring ____

Fiber-optic ArcNet ____

Ethernet 10BaseT ____

Ethernet 10Base2 ____

Token Ring ____

LocalTalk ____

ArcNet ____

A fiber-optic Ethernet solution called 10BaseF is suggested between the two buildings, for two reasons:

• Only fiber-optic cable can offer the distance capabilities necessary to�cover 600 meters (2000 feet).
• A repeater can be used to connect the fiber-optic cable from one building to the 10BaseT cable in the other.

1. List at least two things that could cause those nodes to fail to function.

The cables to the computers that are having problems might not be of the correct category. Category 5 wire, which can handle the 100 Mbps network, is fairly new and might have been too expensive when the older cable runs were installed.

The cables to the computers that are having problems might be of the correct category, but might not have been installed to Category 5 specifications. The cable might work fine for 10BaseT, but fail for 100BaseX.

The patch cables used to connect each of the problem computers to the wall jack might not be Category 5 patch cables and might work for 10BaseT, but not for 100BaseX.

Rough handling during the installation of the new computers might have damaged the existing network cabling.

2. What could you do to resolve each of the possible causes you listed above?

Upgrade to Category 5, and test the cable runs with appropriate test equipment (test equipment is discussed in Chapter 8, "Designing and Installing a Network") to determine if it will support 100-Mbps networking. Replace all cables that will not support your new network.

Test the patch cables with appropriate test equipment to determine if the cable will support 100-Mbps networking. Replace all cables that will not support your new network.

Visually inspect all the cables for damage and replace any that have obvious problems; then test the rest to determine if there are any hidden problems. And of course, replace all cables that will not support your new�network.

1. Access methods prevent _______________________ access to the cable.

simultaneous

2. With CSMA/CD, if there is data on the cable, no other computer may _________________ until the data has reached its destination and the cable is�clear again.

transmit

3. CSMA/CD is known as a _____________________ access method because computers on the network compete for an opportunity to send data.

contention

4. With more traffic on a CSMA/CD network, _______________ tend to increase, slowing the network down.

collisions

5. With the token-passing access method, only one computer at a time can use the token; therefore, there are no ___________________ or _____________________.

collisions, contention

6. With the demand-priority access method, the __________________ manage network access by doing round-robin searches for requests to send from all nodes.

repeaters

7. In the demand-priority access method, transmissions are not __________________ to all other computers on the network.

broadcast

8. A token is a special type of __________________ that circulates around a cable ring.

packet

9. With data masses divided into ______________, individual transmissions occur more frequently so that every computer on the network has more opportunities to transmit and receive data.

packets

10. Packets may contain session-control codes, such as error correction, that indicate the need for a _________________________.

retransmission

11. A packet's components are grouped into three sections: _____________, data, and trailer.

header

12. In a packet, the header usually contains an error-checking component called a CRC. True False

False. The trailer contains this component.

13. The structure of the packets is defined by the communication method, known as a protocol, used by the two computers. True False

True

14. Every network interface card sees all packets sent on its segment, but it interrupts the computer only if the packet's address matches its individual address. True False

True

15. The trailer of a packet contains the destination address. True False

False. The header contains the destination address.

16. Typically, Ethernet is a baseband architecture that uses a ________ topology.

bus

17. Ethernet relies on the __________________ access method to regulate traffic on the main cable segment.

CSMA/CD

18. The maximum length of a 10BaseT segment is ________ meters.

100

19. The 10BaseT topology is an Ethernet network that uses ______________________________ cable to connect stations.

unshielded twisted-pair (UTP)

20. Typically, the hub of a 10BaseT network serves as a _____________________ _____________________.

multiport repeater

21. A thinnet network can combine as many as __________ cable segments connected by four repeaters, but only three segments can have stations attached.

five

22. Because single-segment 10Base2 Ethernet limits would be too confining for a large business, _________________ can be used to join Ethernet segments and extend the network to a total length of 925 meters (about 3035 feet).

repeaters

23. A 10Base5 topology is also referred to as ___________________.

thicknet (or standard Ethernet)

24. Fast Ethernet is another name for the ________________ topology.

100BaseX

25. Ethernet can use several communication _______________ including TCP/IP.

protocols

26. The 100BaseTX topology runs on UTP Category _____ data-grade cable.

5

27. A 100BaseVG network is built on a __________ topology with all computers attached to a hub.

star

28. A Token Ring network is an implementation of IEEE standard _____________.

802.5

29. In the IBM implementation of Token Ring, a star-wired ring, the actual physical ring of cable is in the ________.

hub

30. In a Token Ring frame the Access Control field indicates whether the frame is a _______________ frame or a _____________ frame.

token, data

31. When a frame reaches the destination computer, that computer copies the frame into its _____________ _____________.

receive buffer

32. Token passing is ___________________ , meaning that a computer cannot force its way onto the network as it can in a CSMA/CD environment.

deterministic

33. When a frame returns to its sending computer, that computer ____________ the frame and puts a new token back on the ring.

removes

34. Cables attach the individual clients and servers to the MSAU that works like other ______________ hubs.

passive

35. When an IBM Token Ring network is full, adding another __________ can enlarge the network.

MSAU

36. MSAUs were designed to sense when a _______________ _______________ _________ fails and to disconnect from it.

network interface card

37. Each single Token Ring can accommodate ________ computers using STP cable.

260

38. Most Token Ring networks use IBM Cabling System Type ____ UTP cabling.

3

39. LocalTalk uses __________________ as an access method in a bus or tree topology.

CSMA/CA

40. When a device attached to an AppleTalk network comes online, the device broadcasts an ________________ to determine if any other device is using it.

address

41. A single LocalTalk network supports a maximum of ______ devices.

32

42. Single LocalTalk networks can be joined together into one larger network through the use of _____________.

zones

43. ArcNet uses a token-passing access method in a ________-_______ topology.

star-bus

44. An ArcNet token moves from one computer to the next according to the order in which it is connected to the __________________, regardless of how they are placed on the network environment.

hub

45. Each computer in an ArcNet network is connected by cable to a ________.

hub