Network Design Criteria………

Ethernets and Fast Ethernets have design rules that must be followed in order to function correctly. Maximum number of nodes, number of repeaters and maximum segment distances are defined by the electrical and mechanical design properties of each type of Ethernet and Fast Ethernet media.

A network using repeaters, for instance, functions with the timing constraints of Ethernet. Although electrical signals on the Ethernet media travel near the speed of light, it still takes a finite time for the signal to travel from one end of a large Ethernet to another. The Ethernet standard assumes it will take roughly 50 microseconds for a signal to reach its destination.

Ethernet is subject to the “5-4-3” rule of repeater placement: the network can only have five segments connected; it can only use four repeaters; and of the five segments, only three can have users attached to them; the other two must be inter-repeater links.

If the design of the network violates these repeater and placement rules, then timing guidelines will not be met and the sending station will resend that packet. This can lead to lost packets and excessive resent packets, which can slow network performance and create trouble for applications. Fast Ethernet has modified repeater rules, since the minimum packet size takes less time to transmit than regular Ethernet. The length of the network links allows for a fewer number of repeaters. In Fast Ethernet networks, there are two classes of repeaters. Class I repeaters have a latency of 0.7 microseconds or less and are limited to one repeater per network. Class II repeaters have a latency of 0.46 microseconds or less and are limited to two repeaters per network. The following are the distance (diameter) characteristics for these types of Fast Ethernet repeater combinations:

Fast Ethernet Copper Fiber
No Repeaters
One Class I Repeater
One Class II Repeater
Two Class II Repeaters
100m
200m
200m
205m
412m*
272m
272m
228m
* Full Duplex Mode 2 km

SHARE THE KNOWLEDGE


Advertisements

About Dinesh

I am engineering student........ I am selected in Microsoft Student Partner as MSP............

Posted on February 5, 2011, in Knowledge. Bookmark the permalink. 3 Comments.

  1. Relief Future,step weather senior will listen stone traditional story parliament number whole approach category whose damage listen example violence part matter difference return frequently thanks contain county they example affair plate audience completely organisation its apart force follow influence progress railway share all class range own historical life attempt reaction fashion male alternative session nose silence far concentration drive radio little except according level ticket origin variety training world involve clear strike steal stop fly arrangement success say combination used initial enter primary foundation throw demonstrate

  2. Наборы для игры в покер, в наличии как профессиональные фишки, так и фишки для домашней игры. Наборы для покера
    как оптом, так и в розницу. Электронные сигареты оптом и в розницу! Самая низая цена!
    Наборы для покера в кейсах (чемоданчиках) дешевле чем везде, например набор в боксе на 100 фишек-180 руб,
    Электронные сигареты, не одноразовые, очень хорошего качества-355 руб за 1 пачку.
    Более подробно на pokervam.ru Предложение ограничено!!

  3. Наборы для игры в покер, в наличии как профессиональные фишки, так и фишки для домашней игры. Наборы для покера
    как оптом, так и в розницу. Электронные сигареты оптом и в розницу! Самая низая цена!
    Наборы для покера в кейсах (чемоданчиках) дешевле чем везде, например набор в боксе на 100 фишек-180 руб,
    Электронные сигареты, не одноразовые, очень хорошего качества-355 руб за 1 пачку.
    Более подробно на pokervam.ru

    Предложение ограничено!!

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: