tatal-limit= limit*
400 client, and limit=50 —> total-limit=20000
More info on limit (or queue size) is here:
http://wiki.mikrotik.com/wiki/Queue_Size
Hi,
This is an interesting discussion. To answer Janisk about a more specific requirement, my scenario is as follows:
Total BW is 10 Mbps, and total 500 customers
3 Classes of Shared Clients (kbps down / kbps up)
SC1 => 512 / 128
SC2 => 256 / 64
SC3 => 128 / 64
2 Classes of Dedicated Clients (kbps down / kbps up)
DC1 => 512 / 256
DC2 => 256 / 128
From your excellent PDF attachment, I can understand how max-limit works when I’ve got only one PCQ defined. But, how do I make sure that my 10 Mbps is always fully utilized in this scenario? I would like to use the “unused” BW of when the DCs are not using it. And, I would also like to keep the 10 Mbps to a Flat Line if possible. Am I asking for too much?
Thank you in advance for your valuable input.
Yeah my scenario is similar, I need to know as well, please.
I just found another post in the forum:
http://forum.mikrotik.com/t/is-priority-really-working/24459/1
which has some interesting suggestions. I’ll try to get my hands wet using these principles in the coming days and let you know how it goes. In the meantime, if you do get around doing these things, I would be ever grateful if you could please post your partial configs on the forum.
OK, I get how Limit and Total-Limit works, but I have one question.
Are the limits calculated for each queue (simple/tree) or for whole type?
I mean, If I will create queue type PCQ_Up and PCQ_Down with Limit 2000
And then in queue simple or tree I will make queue for 10.0.1.0/24 and 10.0.2.0/24 (each has also own mangle) both with same PCQ_Up and PCQ_Down, will the Limit be for both together or 2000 for each?
Thanks 
should be 2000 for each bro
I think I have a problem with my simple queues too. I have a hotspot with users coming in which goes forwarded to squid.
what happens is that theres an allocated queue per user from radius as every one knows. my allocated profiles are 20mb down 512up
after a few minutes logging it is fast then it all slows down to a trickle then nothing. then I remove the queue it speeds up to normal.
what am i doing wrong ???
Need this to work correctly
I’ve spent the whole afternoon trying to understand this, I opened tabs on all the links supplied in THIS thread, but before that I was stuck with the mikrotik WiKi, which doesn’t fully explain the Limit and Total Limit and if it applies to ‘each’ sub-stream or the total substreams.
We have a rb1100ah that I just had to upgrade to a 1100AHx2, because CPU is pegged at 100% during peak hours.
There’s about 600 simple queues, most of which are now converted to PCQ’s, about 4 different /24 private IP blocks, and a few /28 and /27’s. We setup 10 different PCQ for down/up, and I’m wondering now if leaving the default Limit:50 and Total Limit: 2000 is the problem?
Let’s say your creating a PCQ for 7Mb Download rate, and you figure you’ll set this to about 300 simple queues. Does the Limit and Total Limit need to be increased??
Try this:
The pcq-limit you can leave 50 and the pcq-total-limit is pcq-limit multiplied by number of connections (so e.g. for /24 it’s 12700).
Works fine for me
Hi Everyone,
I’m also trying to understand the PCQ limit and Total-limit options. What should I do in the following scenario?
Internet Service. Max Download 100Mbps and max Upload 10Mbps. 50 Daily users watching youtube.
The following Queue Types are applied to the Queue Tree. On this case we are limiting each users to 10Mbps down\1Mbps up.
PCQ_Down rate 10M, limit 50, total-limit 2000
PCQ_Up rate 1M limit 50, total-limit 2000
- Should I increase the limit and total-limit to prevent the packets from been drop and queue them instead?
- How do I calculate the limit and total-limit for this scenario?
I don’t know exactly the impact of PCQ-limit, but PCQ-total-limit can be set as I mentioned above - limit*numbers of connection to limit.
So with limit 50 and 50 users I would set total-limit to 2500.
Try and watch
pcq-limit (number) : queue size of single sub-stream (in KiB)
pcq-total-limit (number) : maximum amount of queued data in all sub-streams (in KiB)
Why 50KiB and not more. I still see a high packet dropped if I leave the limit at 50. The Total-Limit doesn’t seem to make a difference on this case maybe because I’m not reaching the total-limit.
If I change the limit to 2000KiB, the packet dropped decreases.
I’m trying to figure out how to calculate the limit and total limit. I really don’t like the guessing game, because I don’t know if what I set will be right or not.
Packet dropping IS how you shape bandwidth. It means your client is sending too fast so you are dropping to throttle him. You WANT dropped packets. Don’t change the queue size.
Rate limitation consist of two things: dropping and delaying.
I know that dropping is how you rate limit, but I’m trying to understand rate equalizing. The limit and total limit will delay the packets instead of dropping them. I’m just trying to find the balance between the two.
First , you queue the packets before dropping them, that’s what the limit is there for.
If the queue is too big, you get a higher latency, if it’s too small you get a high rate of packet loss
Personally, I would try to solve this via trial and error
If the default 50KiB aren’t sufficient and you get a high rate of packetloss, you should consider raising your limit (and total-limit based on your network ofc)
That’s at least my understanding
Hello, How to find out what value to put on set limit and total limit on QOS
Two thumbs up ---- In a closet waiting for response