100% CPU load ?

jager · Thu May 25, 2006 4:38 pm

Please help!
I have the following setup (backhaul link):

RB532 (station 1*SR5) ----15km----RB532(2*SR5)----12km----RB532(station 1*SR5)

Signal levels are more than sufficient (-52, -57)

Every RB has set up a bridge between wlan and ethernet interfaces. Connection tracking disabled, no firewall rules at all. Just simply backhaul from first to third routerboard.
Everything is OK if there is less than 4Mbit traffic. A day ago we started to use more bandwidth on this backhaul, and I was very suprised when packet loss occured. Only then I found out that the CPUs are overloaded. CPU on site 2 is constant 100% while site 1 and 3 was 80% or higher.

I have to say that the other end of the backhaul are 200+ users, 30% of them are P2P leechers (torrent etc.)

Now, i had to lower the bandwidth consumption, redirectiong some of the users to alternate link. At this moment, there is arround 3.2Mbit incoming (1100 packets), and 1.6Mbit (1000 packets) outgoing traffic, CPU load 70-80%

Is is posible that RB532`s CPU is not powerfull enough to handle this ammount of traffic??

Please HELP, I will lose my hair

What suggestion do you have to improve the troughtput on this backhaul? Thanx in advance for help.

Regards,
Jager

ParisDragon · Thu May 25, 2006 9:38 pm

What Queue type are you currently trying?

Are you using WDS or Nstreme for the backhaul?

jager · Fri May 26, 2006 12:43 am

No Queue is set up on boxes.
I`m using WDS, as simple client interface is not bridgable.
If I switch to Nstreme can I bridge that interface too? Will it eat less CPU power than WDS?

Thanx!

karyal · Sun May 28, 2006 1:12 am

No Queue is set up on boxes.
I`m using WDS, as simple client interface is not bridgable.
If I switch to Nstreme can I bridge that interface too?

Yes

Will it eat less CPU power than WDS?

Thanx!

No, it will use much more cpu.. i had a similar situation, with the link loosing packets, i solved by enabling nstream.
The link now can easily do 6 mbps full duplex (and a peak of 12 mbps when just one side of the link is in use..)
I cannot tell you at this time how many pps the link manages (at this time is at it's lowest usage, and is doing about 700 pps on each side, and an average of 2.5 mbps each side)
Cpu load is, at this time, with nstream enable, at a slightly more than 50%
Most traffic is p2p, and this is a backhaul link that ends on the fiber connection to the internet.
User number is around 200 users for us too, but not all users are generating traffic at this moment.
I think you have already disabled what you could do to reduce cpu load, the only difference between your setup and mine is we use cm9 and that i do not use the same rb to handle the traffic betwen site one and three.
i.e. i would suggest you to split the middle RB in two RB, each with one radio card, and connected through the ethernet.
Using the RB to receive and re-launch the data through wireless can really kill its cpu.
You should be able to bridge them anyway
Bye,
Ricky

jager · Sun May 28, 2006 12:26 pm

Ricky, thank you very much for your post!
I was thinking about the same, to split site 2 onto two routerboards. I`ve already ordered new routerboards and SR5 cards.
I had another idea too, to replace the routerboards with much powerful P4 PC`s, but.... The site 2 is on the top of a water tower where it is not allowed to have 220V. I can have 220V at the bottom, and I`m forced to use 50m PoE cable.

What about dual Nstreme? I have no experience with dual radios for the same ptp link. Does this setup eats less CPU? Please, anybody with dual nstreme experience, HELP.

Thank you all in advance.

Regards,
Jager

karyal · Sun May 28, 2006 6:29 pm

Ricky, thank you very much for your post!
I was thinking about the same, to split site 2 onto two routerboards. I`ve already ordered new routerboards and SR5 cards.
I had another idea too, to replace the routerboards with much powerful P4 PC`s, but.... The site 2 is on the top of a water tower where it is not allowed to have 220V. I can have 220V at the bottom, and I`m forced to use 50m PoE cable.

Having more cpu power would be useful here too, but i didn't find yet how (i.e. what product to use)..
Almost all of the equipment i've found do not fit as good as a rb to be placed on a tower.
They need to:
A) use POE (12 or 48v) for power
B) have a fanless setup for realiability (even if you can have 220v on top, you have the power supply fan that can fail, then)
C) be waterproof (or at least "waterproofable")

Note that you can also overclock you rb, i've been told by a collegue that's realiable and that can also give you quite a boost.
I tried on a couple of (not loaded) sites, and i can tell you i have no reliability problems so far..
I didn't take enough courage to test on a more crowded location at this time =)
Bye,
Ricky

yogi · Tue May 30, 2006 1:38 am

VIA motherboards run Mikrotik? :)

This forum and a few others will advise against using the VIA chipset. Look for Intel rather.

jager · Tue May 30, 2006 2:12 am

VIA motherboards run Mikrotik?
This forum and a few others will advise against using the VIA chipset. Look for Intel rather.

Well, ok, but here is what /system resource pci print says on RB532:

1 00:03.0 VIA Technologies, Inc. VT6105 [Rhine-III] (rev: 134) 143
2 00:02.0 VIA Technologies, Inc. VT6105 [Rhine-III] (rev: 134) 142

jarosoup · Tue May 30, 2006 2:22 am

Those are the ethernet controllers, not the cpu/memory/pci bridge controller - 2 very different things. Do a little searching for VIA motherboards, there have been many posts about stability issues when used with wireless radios.

jager · Tue May 30, 2006 2:29 am

I know

Will go for Intel.
Thanx

jager · Thu Jun 01, 2006 12:29 am

I`ve found something that should work OK. In a few days the board will arrive for testing...

http://wlan-ok.hu/index.php?si=297

yogi · Thu Jun 01, 2006 5:45 pm

http://www.commell-sys.com/

http://www.ibase.com.tw/

English web sites well Thai-English

phendry · Sun Jun 04, 2006 11:05 am

What about outdoor enclosures? These (http://starnetwifi.com/product_info.php?products_id=111) would seem to fit the mini-itx form factor but I think a Mobile Celeron would cook inside it.

Hammy · Sun Jun 04, 2006 5:34 pm

http://www.albatron.com.tw/english/it/m ... pro_id=215

That one uses an AMD processor, so it will be more powerful, use less power, and run cooler than an Intel. You can run a Turion processor in it. A Turion only uses 25 watts vs. a Celeron's 84 watts.