Manual:Queues - PCQ

Usage

PCQ was introduce to optimize massive QoS systems where most of the queues was exactly the same only for different sub-streams. For example a sub-stream can be download or upload for one particular client (IP) of connection to server.

PCQ algorithm is very simple - at first it uses selected classifiers to distinguish one sub-stream from another, then applies individual FIFO queue size and limitation on every sub-stream (witch is exactly the same for every sub-stream), then group all sub-streams together and apply global FIFO queue size and limitation.

PCQ parameters:

• pcq-classifier (dst-address | dst-port | src-address | src-port; default: "")  : selection of sub-stream identifiers
• pcq-rate (number) : maximal available data rate of each sub-steam
• pcq-limit (number) : queue size of one sub-stream in packets
• pcq-total-limit (number) : queue size of global FIFO queue

So instead of having 100 queues with 1000kbps limitation for download we can have one PCQ queue with 100 sub-streams

Classifiers

Limit and Total Limit