Alasan mengapa setiap email yang Anda kirimkan selalu sampai tempat tujuan karena disebabkan adanya “tag” yang berisi informasi mengenai tujuan.  Seperti halnya sebuah tas di airport. Bagaimanapun juga, “tag” (sering dikenal sebagai “header” dalam dunia komputer) ada nilai yang harus dibebankan pada bandwidth untuk setiap data yang dikirim melalui protokol TCP (Transmission Control Protocol) melalui internet secara bersamaan. “tag” ini akan membebani bandwidth Anda sebesar 13% (tiga belas per seratus).

Situs pengukur sebuah kecepatan di internet tidak menunjukan angka yang sebenarnya. Karena banyak faktor yang mempengaruhi test kecepatan pada setiap situs.  Hal ini dapat disebabkan karena :

   1. Perbedaan jalur (routing) berbeda antara backbone yang satu dengan lainnya.
   2. Kemampuan server penyedia situs tersebut menerima data.
   3. Besar bandwidth yang dimiliki penyedia situs test kecepatan itu sendiri.
   4. Spesifikasi komputer yang digunakan pada saat melakukan test kecepatan.
   5. Dengan kata lain situs-situs tersebut hanya sebuah ilustrasi saja yang dapat dijadikan estimasi sementara.


Enemy 1: Badly configured PCs
The single most common cause of poor performance is a computer that is in poor shape for broadband. The usual problems are:

    * Insufficient memory (128MB is really the lower limit now for any computer);
    * Underpowered processor (vintage computers from the early 90s with a central processing unit slower than  400MHz);
    * An aging and unstable operating system, accumulation of shareware, particularly SPYWARE etc;
    * Over-clocked motherboards cause unusual problems.

Enemy 2: Packet losses
The Internet is a resilient network built originally to withstand a nuclear war. One reason for this strength is TCP, the network protocol that makes sure your data gets from one point of the Net to another.

TCP is designed around the assumption that some parts of an e-mail message, for example may not get through the Net.

Thus, an e-mail message to be transferred gets broken down into “packets”. For example, 5 packets will attempt to take the fastest route to reach the destination, and when they do, the 5 packets will “combine” to form the original e-mail message.

For the sake of an example, let’s imagine you are downloading data from, and one of those many packets streaming down to you disappears en-route.

Maybe a random outage or failure knocks a network router for a microsecond, and the packet is dropped. At your end, your computer notices the missing packet in the stream of sequence numbers, and so does not acknowledge its reception.

The sender notices the lack of acknowledgement, and must re-transmit the lost data. The retransmission procedure adds to the amount of data flowing over the connection, slowing the entire transfer down.

There are many ways that TCP copes with networks that are down. But in the end, consistent packet loss along a long Internet link means Internet traffic is often slower than it should be, even though it may be one packet in ten or twenty that is being dropped.

If there is continuous packet loss between you, and your favourite site, then Web pages or file transfers, which follow the TCP protocol, are going to slow down to a crawl.

If you see extremely slow performance from a particular website, then you can do a ping test, which shows how many packets are lost along the way.The instructions are as follow:

    * Go to a MS-DOS prompt, and type ping -t (or any website you want to test with)
    * Watch the sequence numbers printed. Leave it running for a short time, say 30 seconds, then press control-c.
    * If you see 5% or more packet loss, then TCP performance is going to be poor over this link.
    * If no packets get through at all, you may have found a server that does not respond to ping packets (some servers do this as a security measure).
    * In that case, use the command tracert (traceroute), to identity the server that is one hop from the target server, and try pinging that instead.

To do a traceroute, the instructions are as follow:-

    * Open a MS-DOS window (command prompt) and use TRACERT, to work out at what point the congestion may be.
    * For example, tracert Trace route may show where in the chain between you and your destination the problem starts, and its nature.

Enemy 3: Many servers cannot currently offer high speeds to you
Though MNET strives to offer the fastest connectivity to the rest of the world, sometimes the weakest, or slowest, link is the one that your website uses to connect to the Net.

Here are some results of a speed test to several reasonably well connected websites, at 12am in the morning (off peak):

In this example, Microsoft and would not provide the "broadband experience" to any user who thought they had speeds of 768kbps or more.

Many servers offer speeds far slower than even this, because they are busy, and you are sharing their bandwidth with dozens of other people.
Speed     1.6mb     310k/sec     2.0mb     280k/sec     5.0mb     67k/sec     5.0mb     66k/sec

All websites have Internet pipes connecting to their web servers. To ensure that all users who access their sites do not get rejected, the bandwidth of their Internet pipes are sliced and divided equally among all users trying to access their site at any one time.

So if the number of users is low, your speeds will be higher, but if the number of users is high, much slower speeds can be expected.

For Indonesia’s internet users, 12am Indonesia time is peak hour for Internet traffic in the United States. This may mean slowdowns to people surfing to US websites, because they have to compete for bandwidth with the rest of the American users.