ADSL Bandwidth Management HOWTO

length from the default of 100, which on an ADSL line could take as much as 10 seconds to empty with a 1500 byte mtu.

-----

3.5. Attempting to Throttle Inbound Traffic

By using the Intermediate Queuing Device (IMQ), we can run all incoming packets through a queue in the same way that we queue outbound packets. Packet priority is much simpler in this case. Since we can only (attempt to) control inbound TCP traffic, we'll put all non-TCP traffic in the 0x00 class, and all TCP traffic in the 0x01 class. We'll also place "small" TCP packets in the 0x00 class since these are most likely ACK packets for outbound data that has already been sent. We'll set up a standard FIFO queue on the 0x00 class, and we'll set up a Random Early Drop (RED) queue on the 0x01 class. RED is better than a FIFO (tail-drop) queue at controlling TCP because it will drop packets before the queue overflows in an attempt to slow down transfers that look like they're about to get out of control. We'll also rate-limit bot