How fast is broadband to unlock the true speed of ADSL puzzle _ Application Skills

Uncover the mystery of real speed

Often use ADSL users, do you know the true speed of ADSL? With this in doubt, we will start the problem step by piece.

Many users reflect that ADSL download rate does not reach the nominal 512K, the brain through ADSL access network, download will appear a download rate indicator bar, the above shown download rate is generally about KBYTE/S! It is actually a misunderstanding caused by the ambiguity of the conversion relationship.

What do you mean, 1,512k ADSL?

512k=512kbps=512k bits/s=64k bytes/s

I think there should be no problem with this conversion.

What does 2,64k bytes/s mean?

The real meaning of this 64K is "the maximum download bandwidth that individual users can enjoy"

Then what does this mean, do not know now has no one to pay attention to the telecommunications ADSL installation application form, the above bandwidth items are written are "no higher than 512K", "not higher than 8M" and so on, that is, we under normal circumstances can have up to no more than 64K of proprietary bandwidth.

Note that "no higher", so that many times our proprietary bandwidth may be less than 64K, that is why?

In fact, China Telecom's ADSL is running on the ATM, ATM to chinanet edge router bandwidth is 155M, each edge router can connect 3000 users, if these users at the same time online, then each user in fact only 50k bit/s bandwidth, that is, 7K bytes /s, coupled with the router attenuation, then may end up with only the speed of the ordinary modem.

Of course, the above is only hypothetical situation, after all, 3000 people at the same time connected to an edge router is almost impossible, telecom will not let the router full load connection and make the speed drop so huge.

However, it is beyond doubt that 64K is the highest proprietary bandwidth.

3, then why my 512K ADSL can often reach 100K or even 200K above the download speed?

We've got it. 64K is the largest proprietary bandwidth, but not the maximum bandwidth, in fact, when ADSL dial-up has been allocated to the actual equivalent of 8Mbps, that is, 1M bytes/s download bandwidth, but telecommunications limited our exclusive bandwidth of the highest 64K, then when the router to connect fewer users, We can get some shared bandwidth over proprietary bandwidth (obviously telecom doesn't have to keep these bandwidth idle), of course, 512K-speed ADSL will never be able to use shared bandwidth to achieve 1m/s download speed, because after all, there are always many people at the same time online, and telecom must also have some balance load mechanism.

The effect of 4,ADSL upload speed on download

TCP/IP regulations, each packet, need to have a acknowledge message, that is, transmission of information, need to have a message to receive information to determine the transmission speed behind,? Decide whether to retransmit the lost information.

The uplink bandwidth is part of the transmission? Some acknowledge (confirm) the material, when the uplink load is too large, it will affect the transmission speed of acknowledge data, and then affect the download speed. This is particularly true for asymmetrical digital loops, which are far less connected to the uplink bandwidth than the download bandwidth.

Tests have shown that when uploaded full load, the download speed is said to be the ideal speed of 40%, which can explain why many friends with BT download time a little speed limit instead can get a larger download speed.

In this way we can not ask all the people are not limited to speed, because for ADSL users this is very unrealistic, but also unscientific. The appropriate speed limit is correct.

The speed of 5,adsl gradually decreases with the extension of connection time.

Previously said ADSL dial-up will build the highest theoretical 8Mbps download bandwidth, this bandwidth will never change! But in fact, because of the noise detection mechanism of ADSL if the wiring is not good, then the initial connection is obviously impossible to achieve the theoretical value, may finally be 5Mbps, this bandwidth will not change.

So why do you think the ADSL speed will be more and more slow?

This is because even if the user does not turn off the modem power, sometimes the ADSL link will be interrupted at any time. For example, the state of communication is deteriorating due to increased noise, and frequent errors occur. Once the link is interrupted, the debugging is immediately restarted and the link is redefined. However, if the noise that is causing the link interruption is still present, (this is generally a larger) the speed of the relink will be lower than the original. Because the link speed determined in debugging is also fixed, the link speed will not improve even after the noise disappears. The longer the ADSL modem is used, the higher the likelihood of this happening, so the connection speed is getting slower.

At this point, if the user restarts the modem, the link is re-established and the speed can be increased. This common sense can be used as a link to reduce the speed of processing countermeasures.

Of course, all of these are based on the ADSL connection itself, the actual situation also includes the Internet situation, the site itself response and so on.

Understanding the above knowledge, you may be enlightened. Originally 512K is not 512KB Ah, only 64KB, whining ~ ~ ~ You also can not reach the 512KB download speed per second.

Really realize ADSL high-speed

ADSL speed to solve the most important point is that the user host to achieve a certain configuration, in order to ensure the hardware ADSL access speed. As the saying goes, "no diamond, no porcelain live", if the personal computer processing performance, you can quickly run the Web browser and mail software, improve the speed of the Internet. If 1Mbps ADSL is installed, but the PC can only install WINDOWS95 or 98, of course, it will feel slow. Especially if the memory is only 64MB or 128MB, broadband is like a hero useless martial place. If the PC is updated, the operating system can use Windows XP, and the speed of natural broadband access will increase. In addition, Windows XP requires more memory than the original windows-based system, and it is recommended to have at least 256MB of memory. If you don't have the ability to update your PC, increase the memory and feel the speed increase as long as you increase the memory. In addition, the ADSL modem used in broadband access also supports high speeds to ensure access speed.

There are also some hardware on the ADSL maintenance methods, such as to shorten the phone between the telephone and ADSL modem telephone line, you can minimize line loss, the specific operation can shorten the distance between the telephone socket and the ADSL modem, lengthened connection between the modem and personal computer cable, will not reduce the speed. In the vicinity of ADSL modems do not place electromagnetic waves of office equipment (including personal computers) or television, refrigerators and other home appliances, mobile phones will bring interference to the modem.

People familiar with computers should know that the performance of personal computers depends not only on their own hardware base, later on the computer software optimization can also become the power of the network to fly. On the one hand, the system's own performance can be through more than some "flooding" system optimization software to improve, CPU vacancy rate, memory usage, hard disk debris cleanup, etc., can be achieved through the power of the software to improve. On the other hand, in the broadband Access connection network, can also use some specialized software optimization, some network connection settings for random adjustment to achieve the best connection effect.