- •Lan Switches Part 1. Introduction to lan Switches
- •Part 2. Networking Basics
- •Part 3. Network Topologies
- •Essential vocabulary (1), (2), (3)
- •Exercises
- •1. Find in parts 1, 2 and 3 of the text English equivalents for the following words and phrases:
- •8. Translate these passages in writing:
- •9. Answer the following questions using the information from parts 1, 2 and 3 of the text.
- •10. Decide whether the following statements are true (t) or false (f) in the relation to the information in parts 1, 2 and 3 of the text. If you think a statement is false, change it to make it true.
- •The Network Switch
- •13. In the box below you can see three topologies of a network. Give main advantages and main disadvantages of each of them.
- •14. Render the following text in English. Характеристики, влияющие на производительность коммутаторов.
The Network Switch
A network switch (to be) a small hardware device that (to join) multiple computers together within one local area network (LAN). Technically, network switches (to operate) at layer two (Data Link Layer) of the OSI model.
Network switches appear nearly identical to network hubs, but a switch generally (to contain) more intelligence and a slightly higher price tag than a hub. Unlike hubs, network switches are capable of (to inspect) data packets as they (to be received), (to determine) the source and destination device of each packet, and forwarding them appropriately. By (to deliver) messages only to the connected device intended, a network switch (to conserve) network bandwidth and (to offer) generally better performance than a hub.
As with hubs, Ethernet implementations of network switches (to be) the most common. Mainstream Ethernet network switches (to support) either 10/100 Mbps Fast Ethernet or Gigabit Ethernet (10/100/1000) standards.
Different models of network switches (to support) differing numbers of connected devices. Most consumer-grade network switches (to provide) either four or eight connections for Ethernet devices. Switches can (to connect) to each other, a so-called daisy chaining method (to add) progressively larger number of devices to a LAN.
(By Bradley Mitchell)
13. In the box below you can see three topologies of a network. Give main advantages and main disadvantages of each of them.
|
|
|
||
Main Advantages |
Main Disadvantages |
|||
a. It’s easy to connect a computer or device. |
a. The entire network depends on a central hub and a failure of the central hub can cripple the whole network. |
|||
b. One malfunctioning node doesn't affect the rest of the network.
|
b. The entire network shuts down if there is a break in the main wire and it can be difficult to identify the problem if the network shuts down. |
|||
c. It is a good choice for large computer networks as this topology "divides" the whole network into parts that are more easily manageable. |
c. If the central computer fails, the entire network becomes unusable.
|
|||
14. Render the following text in English. Характеристики, влияющие на производительность коммутаторов.
Производительность коммутатора – то свойство, которое сетевые интеграторы и администраторы ждут от этого устройства в первую очередь.
Основными показателями коммутатора, характеризующими его производительность, являются:
скорость фильтрации кадров;
скорость продвижения кадров;
пропускная способность;
задержка передачи кадра.
Кроме того, существует несколько характеристик коммутатора, которые в наибольшей степени влияют на указанные характеристики производительности. К ним относятся:
тип коммутации – «на лету» или с полной буферизацией;
размер буфера (буферов) кадров;
производительность внутренней шины;
производительность процессора или процессоров;
размер внутренней адресной таблицы.
(Олифер В.Г., Олифер Н.А. «Компьютерные сети.
Принципы, технологии, протоколы»)