PPPd is the PPP connection daemon. It will try to connect to a server using a specified speed. The default
speed is 38400. If you use a serial connection, or a 56.7Kbps modem, it may not be enough. If you want to
use all the available bandwidth, you need to increase that number. For example, for a serial connection, you
want the speed set at 115200.
Another reason for speed drops is unwanted packets. You may want to filter unwanted packets out of your
network, like some ICMP messages and chat connections.
A last possibility for speed drops is Denial of Service attacks. DoS attacks are unfortunately very real and
they occur a lot. Malicious people that can’t handle their problems elsewhere turn to the Internet and launch
attacks against networks. An attack against one user will always affect several thousands of people. By using
bandwidth of an Internet provider to cause trouble to any one user, the whole provider will be affected. To
prevent such attacks, firewalls exist, and tracking tools were invented to deal with abusers. MCI has a tool
called DoSTrack that can be of help if you are victim of such an attack. For more information about various
DoS attacks, you should search the Web.