latency

Products PMP
1

Hi guys, been away for a while, come back to find my RF in a mess. The latency is extremely high (fluctuating between 200-500ms)

we have about 100SM registered to an AP ( P8/P9) 30% on VLANS. 5.8GHz, 7.2.9 SW scheduling, NON-advantage platform.

Customers NAT enabled or disabled return fluctuating latency. Disabling the NAT on the SM and then pinging directly to the AP, latency can be as high as 400ms.

Any ideas what could be causing this issue ?

Rgds
Ash

2

i have had bit torrents raise my latency to a constant 200-500ms…today i had 15 customers doing bit torrents and i was running a 900ms latency for a lil bit…no idea whats causes it, any suggestions?

vince

3

Hi Vince, I have my theories, but need to build up my test tools again to start proving/disproving my theories.

Bit torrent works by breaking files into many small packets, Canopy kit has a limit on the number of packets it can handle, which is extremely low.
I think we are probably maxing out the number of packets before we max the bandwidth.

Also, althouhg Moto claim upto 200 SM can register to an AP, which is fine, but I think when you have 200SM’s registered,even if they are not doing anything, the AP is probably using significant processing power to keep track of them, hence introducing latency.

Like I said, I have been away for a little while so I’m trying to gauge if others have come across similar issues.

4

I’d agree that you’re reaching the packets per second limit on the APs. I once read somewhere what that limit was, but I can’t find that information right now. I’ll let you know if I find it.

5

Its hidden in the User Guide Page 61.

6

the way i understand it the 200 sub limit was for software schedule only when in hardware mode expect half or something like that.

also to stop bit torrents you need to setup a linux box with mikrotik you can adjust the amount of bandwidth per port for instance you could set all torrents to only work at 10 k or something but everything elso like on port 80 or 25 would still be fast.

we about got it working i will keep you posted

7

I’ve just migrated our RF (900 SM) to h/w scheduling, I hope it improves throughput…

bit torrent not only causes bandwidth issue its the high number of small packets it generates that hurts…


if you go into the CMM and look at the stats it shows the number of packets in different sizes… Canopy bandwidth figures are based on the 1500byte size