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MCSE Help : 70-058 - Networking Essentials (Part 1)
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Richard Adams guides us through the first half of examination 70-058: Networking Essentials
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As before, we will be focusing on how to pass the examination by explaining exam content, types of questions to look out for and the vital knowledge that you need to gain that all-important ‘Pass’ mark.

General Advice

This is the one MCSE examination that is not tied to a specific Microsoft product, but instead is designed to test your overall knowledge of general networking theory, components and terminology. However, there is, without doubt, a slant towards NT (and even Windows 95) in the questions, so my advice to those who are not already familiar with Windows NT is to revise for and pass your NT examinations first and then worry about Networking Essentials.

Another unique thing about the Networking Essentials examination is that Microsoft does not have an Official Curriculum trainer-led course available to learn it. Instead it offers a self-study ‘kit’ which incorporates a book and a CD-ROM from which they recommend you revise prior to sitting the exam. This self-study kit is published by Microsoft Press and is available in all good PC bookshops. I strongly recommend buying it (or one of the many self-study books from other publishers) even if you are already proficient in networking. The self-study kit is invaluable because it shows you how Microsoft uses terminology, how Microsoft defines differences between components and how Microsoft wants you to answer the questions in the exam.

Exam Breakdown

The Server exam has 4 sections: Standards and Terminology, Planning, (we will examine these two sections this month) Implementation, and Troubleshooting (which we will look at next month). As usual, we will take each section separately, list the different subjects that you could get asked about in that section and then give hints and tips on the types of pitfalls and traps you might come across in any one particular question.

The Standards and Terminology Section

What to Revise


Client/Server Vs Peer-to-Peer Network Models, Network Connectivity Devices, Cabling Components, Media Access Models, Share-Level Vs User-Level Security Models, Routing Tables, Layers of the OSI Model, WAN Topologies, LAN Topologies, Protocols, NDIS and ODI, The Universal Naming Convention, Connection-Oriented Vs Connectionless, Dial-Up Protocols, Project 802 Standards, Baseband and Broadband Signalling, Wireless Connections.

Watch For:

1. Network Connectivity Devices - Make sure you know definitions for each of the following, when to and when not to employ them and at which layer/s of the OSI model they work: Repeaters, Bridges, Routers, Brouters and Gateways.


2. Cabling Components - You will get a lot of questions on this subject so thoroughly revise the following: Cabling Topologies, Cable Types, Media Access Methods, Connectors, most common combinations (e.g. Star Wired Token Ring using STP cabling with IBM connectors) and when you are likely to see them being used. Make sure you know all the facts and figures for each component or topology (e.g. 10BaseT segments have a maximum length of 100 metres).


3. Routing Tables - Make sure that you are confident that you understand what a routing table is, what its purpose is and which protocols and connectivity devices make use of them. Watch out for ATP (part of the AppleTalk protocol suite) as you may get asked a question about it and whether or not it can use a routing table (it can).


4. Layers of the OSI Model - The OSI model is the most important subject, after cabling, to get right. You will need to understand Microsoft’s definitions for the responsibilities of each of the seven layers, including both of the sub-layers of the Data Link layer. You must also be aware of which layer each hardware and software networking component operates at.


5. WAN Topologies and Components - You will be asked to define the different WAN standards – ISDN, X25, Frame Relay, ATM, etc, the different topologies – point-to-point, Permanent virtual circuits, etc, and capacities – ISDN Primary and Basic rate, T1, T3, etc.


6. Protocols - You must be able to define each of the following protocols, their common usage, advantages, disadvantages, where they fit in the OSI model (and in the case of TCP/IP, each protocol within the suite): TCP/IP, NetBEUI, NWLink, AppleTalk, DLC. You may well be asked how to add a protocol to the NT environment.


7. NDIS and ODI - Be prepared to answer questions regarding the differences and similarities between NDIS and ODI, how many network cards and how many protocols can be bound together using NDIS and ODI, the different NDIS versions and the difference between real mode and virtualised components.


8. Connection-Oriented Vs Connectionless - Connection-oriented protocols guarantee the safe and error-free delivery of a message over the network, but in doing so incur severe penalties in terms of speed and efficiency. Connectionless protocols are the exact opposite of this – they do not guarantee safe, error-free delivery but operate much faster and more efficiently. User data (such as a spreadsheet document or a report) is almost always sent via a connection-oriented mechanism in order to ensure that the date is not lost. Much of the ongoing background traffic generated to support the network (such as browser announcements) is sent via a connectionless mechanism in order to maximise network efficiency.


9. Dial-Up Protocols - Two dial-up protocols are supported by NT – PPP and SLIP. Of the two, SLIP (Serial Line Internet Protocol) is the older and less versatile. SLIP only supports TCP/IP and requires either manual configuration of IP addressing information or else a custom script as it does not support dynamic IP address allocation. PPP (Point to Point Protocol) supports TCP/IP, NetBEUI and NWLink and also supports dynamic allocation of IP addressing information. NT supports PPP in both client and server formats, whereas SLIP is supported only for the client side.


10. Project 802 Standards - Project 802 was developed to further define and refine standards for the Physical and Datalink layers of the OSI model. Make sure you know what each 802 standard defines.


11. Baseband Vs Broadband - Baseband describes using the entire frequency spectrum of the medium to send a signal. This is usually associated with digital signalling. Broadband describes using different frequencies to simultaneously transmit multiple signals and is usually associated with analogue signalling.

The Planning Section

What to Revise:

Use of Connectivity Devices
Selecting Appropriate Cabling
Bus Types
Differences between Bridges and Routers
Sliding Windows
Selecting the Appropriate Connector
Selecting the Appropriate Network Protocol
Selecting the Appropriate Network Access Method
Selecting User-Level or Share-Level Security
Multiplexing
RAID
Selecting the Appropriate Wiring Topology
Using Subnet Masks
Avoiding Crosstalk
Repeating a Broadband Signal
Routing Protocols
The Purpose of a Transceiver
The Purpose of SNMP

Watch For:

1. Use of Connectivity Devices

You will need to answer scenario-based questions on choosing the appropriate connectivity device to use in the given circumstances of the question. You will also be asked for definitions of the tasks of each connectivity device and the layer/s of the OSI model it operates in.

2. Selecting Appropriate Cabling

You will need to answer scenario-based questions on choosing the appropriate cable type, based upon the information provided in the question. To answer this, make sure you know your maximum and minimum cable lengths, the correct cable type or types to use for a given topology (e.g. star wired) and the correct types of connector.

3. Bus Types

You get asked which bus type is the best to use for a network interface card. The answer is an EISA bus with shared memory.

4. Differences between Bridges and Routers

The differences between bridges and routers are not immediately obvious, as they both perform very similar tasks. Both bridges and routers subdivide a network into subnets and can connect dissimilar topologies and cable types using a routing table to make forwarding decisions, but differ in the way that they do so. A bridge works at the Data Link layer of the OSI model and uses the physical (MAC) address of each node to build its routing table. A router works at the Network layer of the OSI model and uses logical addresses (such as the IP address for TCP/IP) for each subnet to build its routing table. Bridges are able to route any network protocol, whereas routers can only route protocols that use a logical addressing scheme. Bridges can only forward messages to a node in one direction, whereas routers can forward messages to a host in multiple directions. Bridges propagate broadcasts to all subnets, whereas routers do not (by default) propagate broadcasts.

5. Sliding Windows

Used by network protocols such as TCP/IP, each node has a send window and a receive window. The size of the send window determines the amount of data that can be sent across the network in one go, before waiting for an acknowledgement from the receiving computer. The size of the receive window determines the amount of data that can be received in one go before sending an acknowledgement to the sending computer. The acknowledgement acts as a basic guarantee that the data has arrived safely and enables the sending machine to slide forwards to the next set of data to be sent. To optimise the sliding windows environment, it is recommended to have the send window set to a larger size than the receive window.

6. Multiplexing

You will need to understand the use of multiplexing. Multiplexing is the combining of multiple data messages onto a single transmission signal, which is then sent across the media and divided back into its constituent messages at the other end. This system makes for far more efficient usage of transmission media and is commonly used in WAN connections and telecommunications. The devise used at each end of the transmission is called a multiplexor.

7. RAID

Make sure you know definitions for each RAID level and, what mirror sets and stripe sets with parity are used for.

8. Repeating a Broadband Signal

The device used to repeat the signal in a baseband transmission is called a repeater, but the device used to repeat the signal in a broadband (analogue) transmission is called an amplifier.

9. Routing Protocols

Learn the differences between OSPF and RIP. RIP is the only routing protocol that can be installed as a service on Windows NT computers acting as routers and uses a distance-vector algorithm.

10. The Purpose of a Transceiver

A transceiver converts the internal, parallel signal of the computer into a serial signal suitable for transmission over a network and vice versa. Most network interface cards have built-in transceivers, but the 10Base5 (thicknet) topology uses external transceivers.

Richard Adams is an Executive Technical Director for Additional Resources, an IT training company.