CABLE 可以寬頻最佳化嗎 ?

[YICHANG]

最初由 垃圾貓 發表
這是我的群健的抓圖，是不是瘋了？


1.5MB/384K

群賤的主管.每天都會來這看.惦惦用就好了..你貼這些圖.人家馬上就去查囉!!

[垃圾貓]

喔，那殺了。來不及了...你怎知到會來看，莫非您是主管？

[YICHANG]

最初由 垃圾貓 發表
喔，那殺了。來不及了...你怎知到會來看，莫非您是主管？

我還沒衰到想當群賤的員工!!
只能說:內幕消息...

[chih_haohung]

最初由 YICHANG 發表
我還沒衰到想當群賤的員工!!
只能說:內幕消息...

好久沒去http://wwww.speedguide.net 去了 大約快半年了
沒想到已經更新版面了
變得乾淨有系統 有順序多了 且分類更好了 而且內容更棒了 希望大家有空去看看


下面取自
http://www.speedguide.net
Articles的Bits, Bytes and Bandwidth Reference Guide
由Philip所撰寫


Bits, Bytes and Bandwidth Reference Guide
01.01.2001 01:53 EST by Philip

Quick Conversions...

For a quick reference, ue our Bits/Bytes Conversion Calculator.
For the few people that care to learn it right (or be confused to death), read on



The Bits vs. Bytes Confusion

Let's start with some background information on prefixes, by mentioning the Metric system:

kilo (k)* = 10 ^ 3 = 1,000 thousand
mega (M) = 10 ^ 6 = 1,000,000 million
giga (G) = 10 ^ 9 = 1,000,000,000 billion
tera (T) = 10 ^ 12 = 1,000,000,000,000 trillion
* Note that according to the Metric system, the "k" or "kilo" prefix is always lowercase.
The binary forms of kilobytes and megabytes have become standard throughout the computer industry, although they are incorrect uses of the SI prefixes (in the IT field lowercase "k" is used to describe decimal kilobits, and capital "K" is used for binary kilobytes).

When used to describe Data Transfer Rate, bits/bytes are calculated as in the metric system

In data communications, a kilobit is a thousand bits, or 1,000 bits. It's commonly used for measuring the amount of data that is transferred in a second between two telecommunication points. Kilobits per second is usually shortened to kbps or Kbps**. Some sources define a kilobit to mean 1,024 bits. Although the bit is a unit of the binary number system, bits in data communications are discrete signal pulses and have historically been counted using the decimal number system. For example, 28.8 kilobits per second (kbps) is 28,800 bits per second.

1 bit (b) = 0 or 1 = one binary digit
1 kilobit ( kb) = 10^3 bits = 1,000 bits
1 Megabit (Mb) = 10^6 bits = 1,000,000 bits
1 Gigabit (Gb) = 10^9 bits = 1,000,000,000 bits
** Note: Although technically speaking, the term kilobit should have a lowercase initial letter, most published reports capitalize it in abbreviation, resulting in "56 Kbps," or even the really confusing "56K." That leaves you with the sometimes omitted lowercase "b" to distinguish between bits (b) and bytes (B). When used as a measurement of network data transfers, or throughput, always assume the word is bits first.

When used to describe Memory Size, or Data Storage bits/bytes are generally calculated as some exponent of 2

In Data storage, and when describing Memory size, a Kilobyte is 2^10, or 1024 bytes. Because of binary computer architecture and memory address boundaries, bytes are always some multiple or exponent of two.

1 byte (B) = 8 bits (b)
1 Kilobyte (K / KB) = 2^10 bytes = 1,024 bytes
1 Megabyte (M / MB) = 2^20 bytes = 1,048,576 bytes
1 Gigabyte (G / GB) = 2^30 bytes = 1,073,741,824 bytes
1 Terabyte (T / TB) = 2^40 bytes = 1,099,511,627,776 bytes
Although data storage capacity, such as on hard drives is generally expressed in binary Megabytes (2^20), most Hard disk manufacturers, and some newer BIOSes use decimal megabytes (10^6), which is slightly different and it gets confusing...

1 byte (B) = 8 bits (b)
1 Kilobyte (K / KB) = 10^3 bytes = 1,000 bytes
1 Megabyte (M / MB) = 10^6 bytes = 1,000,000 bytes
1 Gigabyte (G / GB) = 10^9 bytes = 1,000,000,000 bytes
1 Terabyte (T / TB) = 10^12 bytes = 1,000,000,000,000 bytes


Abbreviations Table

bit b 0 or 1
byte B 8 bits
kilobit kb 1000 bits
kilobyte (binary) KB 1024 bytes
kilobyte (decimal) KB 1000 bytes
Megabit Mb 1000 kilobits
Megabyte (binary) MB 1024 Kilobytes
Megabyte (decimal) MB 1000 Kilobytes
Gigabit Gb 1000 Megabits
Gigabyte (binary) GB 1024 Megabytes
Gigabyte (decimal) GB 1000 Megabytes




Bandwidth Reference Table

DS0 (digital signal 0) is digital transmission rate of 64 Kbps, the bandwidth normally used for one telephone voice channel. It is the base multiple for both T (North America) and E (Europe) DS (digital signal) carriers.

The following table summarizes the set of signals and their relationship to the T-carrier and E-carrier systems

SG Bandwidth Reference Table

DSx / Ex / Jx Data rate DS0 multiple Carrier
DS0(E0/J0) 64 kbps 1
128 kbps 2 ISDN
DS1 1.544 Mbps 23 (24) T1
E1 2.048 Mbps 30 (32) E1
DS1C / J1C 3.152 Mbps 46 (48) T1C / J1C
DS2 / J2 6.312 Mbps 92 (96) T2 / J2
E2 8.448 Mbps 120 (132) E2
J3 32.064 Mbps 480 J3
E3 34.368 Mbps 480 (537) E3
DS3 44.736 Mbps 644 (672) T3
STS1 51.84 Mbps 672 OC1
DS3C 89.472 Mbps 1288 (1344) T3C
J4 97.728 Mbps 1440 J3C
DS3X 134.208 Mbps 1932 (2016) T3X
E4 139.264 Mbps 1920 (2148) E4
STS-3 / SDH-1 155.52 Mbps 2016 OC3
DS4 274.176 Mbps 3864 (4032) T4
J5 400.352 Mbps 5760 J4
DS4E 411.264 Mbps 5796 (6048) T4E
STS-9 / SDH-3 466.56 Mbps 6048 OC9
DS4C 560.160 Mbps 7728 (8064) T4C
E5 565.148 Mbps 7680 (8592) E5 (4 E4 chnnels)
STS-12 / SDH-4 622.08 Mbps 8064 OC12
DS4X 822.528 Mbps 11592 (12096) T4X
STS-18 / SDH-6 933.12 Mbps 12096 OC18
DS5 1.120 Gbps 15456 (16128) T5
STS-24 / SDH-8 1.244 Gbps 16128 OC24
DS5X 1.400 Gbps 19320 (20160) T5X
DS5E 1.680 Gbps 23184 (24192) T5E
STS-36 / SDH-12 1.866 Gbps 24192 OC36
STS-48 / SDH-16 2.488 Gbps 32256 OC48
STS-96 / SDH-32 4.976 Gbps 64512 OC96
STS-192 / SDH-64 9.952 Gbps 129024 OC192
STS-256 13.271 Gbps 172032 OC256
STS-768 / SDH-256 39.813 Gbps 516096 OC768


Note: The following digital signal levels are not standardized and/or are not in common use:
DS3C, DS3X, DS4E, DS4C, DS4X, DS5, DS5X, DS5E, E5, J5, STS-9, STS-18, STS-24, STS-36, STS-256, STS-768.

我是覺得這一篇文章蠻有趣的 也導正一些人的觀念
資料通訊過程中 1kbit=1000bits 而不是1024bits 依此類推
那24bits跑到哪裡去了呢 雖然bit是2進位 但bit在資料通訊 只是一種分離訊號脈衝 而且已被用十進位算過了 所以在資料的傳送過程是用十進位 而非2進位 一般人把電話撥接的速度 寫為56k 換算成57334bits 是不適當的說法 應該是56000bits 才適當 .............






還有一些不錯的資源 你們自己可以上去看看喔

[tsuick]

最初由 xtiger 發表
台南 GIGA 雙向CABLE_6MB/256K

最佳化前：最經常穩定的下載速率 500-550 KB
最佳化後：最經常穩定的下載速率 600-650 KB

※而且前5秒都會飆到900KB以上，慢慢800KB、700KB…一路降到一個穩定速率
是否ISP限速的效應啟動，試過國內好幾個站，感覺下載有變快了。

※網頁顯示不知道是不是有錯覺，反而慢了一拍，因為都很快無法比較，但憑
感覺似乎少一點流暢，並不是很明顯就是了。
:jocky:

請問這是不是Giga專享的下載網站，這些網站下載是最快的(比一般伺服器還要快)。 香港也有類似的軟件下載站，稱之為寬頻牛牛，你不信的話我試一次給你們看看。

[riddle]

good