pcq config: pcq-limit and pcq-total-limit settings - how to

RouterOS General
1

Hello friends,

I just wonder how to tune-up my pcq configuration. Bad working pcq-rules depending of “pcq-limit” and “pcq-total-limit” values.

I’ve read wiki pages, Megis’ howto, and everything posted on the forum, that can be found.

For example, let us consider downstream limitation of “VIP” customers on the router such as follows:

name=“VIP_down” kind=pcq pcq-rate=40000000 pcq-limit=40
pcq-classifier=dst-address pcq-total-limit=50000

In the mangle one C-class network marked as VIP. Actually 40 customers worked there. If pcq-total-limit set to 2000 or 5000 actual traffic shaped to 5Mbps each VIP customer. If 50000 - to 10-12Mbps.

What is the right compute algorithm to set right values to the traffic shapers. I want to set 60 customers to work to maximum 40Mbps with such queue.

2

pcq-limit is how many packets can be held up in the queue per dynamic sub-queue. When the queue is full and the rate limit is still being exceeded packets are dropped. 50 is a pretty good value. pcq-total-limit should simply be the pcq-limit multiplied by the number of users you expect to simultaneously cause traffic.

3

thank you

4

from my experience when setting pcq-limit to 50 i get about 1.2MBps speed, at about 150 i get about 1.8MBps speed

5

on what version? in ROS v5 PCQ was a bit rewitten =)

6

could you tell us what is on v5

Regards,
Chavdar

7

http://wiki.mikrotik.com/wiki/Manual:Queues_-_PCQ#New_PCQ_implementation_.28v5.0RC5.29