Hello
By default when you specify a queue type pcq limit is 50 and total limit is 2000
What pipe size/number of customers is this tuned for?
I don’t limit my customers but want to have fair sharing.
What would be good for 500 customers & a 4 Meg pipe? (running flat-out all the time)
Thanks 
Bump. All need extended maximum explanation to pcq-limit and pcq-total-limit. In WiKi. By Janis & Normis preferably.
here is the answer → http://mum.mikrotik.com/presentations/US08/janism.pdf
It’s not explained in maximum detail. All possible scenarios must be covered. PCQ behavior is much more complex than what is talked about in the PDF as I have tested.
what else you need? (check slide 26 in janism presentation)
if you have question - then ask direct question - not overall - need to look for more detail…
The week before MUM Europe 2009, Janis M. will teach the Bandwidth Management training class for 4 days, You are welcome to join us there: http://www.mikrotik.com/training.php
P.S: only note! Attendance of previous Training Class either by MikroTik or our Certified Trainers is required to sign up for this class
Please, if someone attends training, post useful material in WiKi afterward. Some PDFs + a little explanation would be great. he he.
P.S. I am planning to become a certified consultant but now is too early for these classes. Thanks.
You shouldn’t have to attend a training seminar to understand PCQ or other parts of Mikrotik RouterOS. Better documentation is all that is needed. But for whatever reason, Mikrotik would rather charge you for a training seminor and not answer your questions…
I think training is good ONLY for people who dont have free time to read the manual , wiki and whts going on in this forum ..
what else except repeating the manual ?
I have a question about simple Q :
as you know simple q’s are processed acording to thier order , but they got priority value also , so what if rule No 1 got priority =8 , last rule lets say No 200 got priority = 1 ? which is the important here ? order or priority ?
My current understanding (untested) is that: In the case of Simple Queues, the order is for ‘catching traffic’ (mangle) and the priority is for packet rearrangement in the HTB.
I understand that PCQ Limit sets how many packets each dynamic queue can hold. The default is 50, so each dynamic queue created can hold up to 50 packets before dropping new packets. What affect (good and bad) does adjsuting the PCQ Limit Up or Down have? I understand it uses more memmory if you increase it, but performance differences is what I’m curious about.
Also what happens if you max your PCQ Total Limit out? PCQ Total Limit is set to 2000 by default. If I understand the information I read, PCQ Total Limit defines the TOTAL number of packets that set of PCQ queues can handle. So, if you do the math, the default PCQ Limit of 50 and Total Limit of 2000 is good for up to 40 concurrent users, assuming they are all being queued at the same time. So what happens if you max your PCQ Total Limit setting out? Are all new packets dropped until there is less then PCQ Total Limit packets in the queue? I would assume this would cause some bad performance in that queue?
I guess they are not dropped but queued with the next pcq cycle and the first ones are sent up the tree/out to interface.
But why waste energy guessing when MIKROTIK IS RESPONSIBLE FOR documenting it !!!
Normis, Janis, Sergej, please.
PCQ—> “MikroTik prorietary”
TELL US HOW IT WORKS.
you know everything you should know.
and apply your networking knowledge - what happens if queue is full - packets are dropped, because, there is no place to put them.
so, TCP traffic is important one, and as you know, when tcp packet is dropped, it is resend again, after some time, therefore, TCP knows, that you have to send packets at slower rate.
and if you check out manual and articles, and presentations - you get all the information we can give you about PCQ.
while some say - that mikrotik is pushing for training - well, it is not so, because in training you get a lot of additional experience that lecturer has. And of course, we are working to improve our manual, that you can find on wiki.
Thank you for answering our question
I hope you can help with some much more complex questions in the future, in the forum.
maybe this new article will give you some insight:
http://wiki.mikrotik.com/wiki/Queue_Size
Thanks Give us more! Maybe some PCQ diagrams and charts?
It is already there:
http://wiki.mikrotik.com/wiki/PCQ
maybe this new article will give you some insight:
http://wiki.mikrotik.com/wiki/Queue_Size
Queue Size=Unlimited, Is it good for UDP or Voice?
how it can be good?
how huge queue size - resulting in high latency, if there is a lot of traffic and queues are heavily used, will improve your VoIP?
it goes like this - bigger the queue, more packets queued, more latency, more latency.
out of order udp AFAIK is dropped
That is there yes, but this discussion is about limit and total limit.
There is just a little in janism.pdf about it, but what we really want NOW is results of experiments with pcq-limit and pcq-total limit presented in color graphic + short explanations. Thank you.