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發表於 2011-7-1 03:00:54
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本帖最後由 lux138 於 2011-7-1 03:59 編輯
I always smile when I see ISP selling broad band and quoting speed (Bandwidth) of over 100Mbps.
1) The speed they quote is the absolute maximum speed and is never achieved.
What you should ask is the minimum speed they can guarantee and what is the average speed i.e. substained throughput.
2) Understand the concept of bottleneck.
For example the common computer network cable is cat 5 UTP which has a maximum speed of 100Mbps.
The cable you get with an ADSL modem is often a 2 wire or 4 wire cable is not the same as the proper 4 pair (8 wire) copper cable.
Do you know what type of cable is used to connect your PC to the ISP's network device (e.g. ADSL modem)
What is the speed of your network interface card ? Is it a Gigabyte (1000mbps) card ?
(e.g. if you using a 100Mbps network card how can you use a 200Mbps connection)
If you care using a Cat 5 UTP cable runing 1000Mbps how can you use a 200Mbps connection
3) Know your ISP's internet backbone bandwidth. And again understand the concept of bottleneck.
The speed they quote is the speed from your home to their network equipment.
The speed from your PC to the internet will be lower!
4) Fiber Optic is NOT faster than copper. Cat 5e/Cat 6 Copper cable can run up to 1000 Mbps
(The real advantage of Fiber Optic is not speed but the distance it can run before requiring a repeater)
Fiber optic cable is only used for Backbone network. (hint: what happens when you bend a fiber optic cable ?)
As a user you really should not care whether the ISP is using Copper or Fiber Optic.
5) A stable network performance with good average speed is a million times better than a high maximum thoretical speed.
6) Do you know your ISP's "fair use policy " ?
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