Task: Test Max Speed doable using Mikrotik NStreme
2 (two MPCI cards in one board).
test environment...
AMD 3Ghz Laptop wired -> Mikrotik 532 w/ CM9
-> Mikrotik 532 w/CM9 -> wired to HP PIII-800Mhz Laptop.
Connected in a lab environment, zero
noise.
Mikrotik OS ver 2.9.28
Test software 1: IPerf TCP running on both
Laptops.
Test software 2: Mikrotik Bandwidth test running on
Mikrotiks.
Test Method 1 (running test
to/from Laptops): used about 80% CPU power on Mikrotik board to pass the
traffic.
Test Method 2 (running to.from MIkrotik): used
about 100% CPU power on Mikrotik.
However, interesting enough, the results of the
speed tests, whichever method used, were just about identical, give or take 1
mbps.
The results of tests were....
Maximum speed transferable in one direction 20Mhz
channel: 16.6 mbps.
Maximum speed transferable in both direction
simultaneously (adding together the values) 20.8 mbps (13.8 mbps and 7 mbps
in the other).
Maximum speed transferable in one direction 10 mhz
channel: 15.8 mbps.
Maximum speed transferable in both directions 10
Mhz channel: 19 mbps (10.4 mbps and 9 mbps)
Maximum speed transferable in one direction Turbo
Mode speed: 18 mbps
Maximum speed transferable in both
direction simultaneously Turbo Mode (adding together the values):
22mbps.
Note: Turbo mode tested in two configurations, (A)
the lowest 5.8G channel send and highest 5.8G channel for receive, and (B)
5.8Ghz to send and 5.3Ghz receive.
Note: All 5.8Ghz test results were at 54
mbps speed modulation, and setting it to slower speed/modulation lowered the
test speed results.
Note: Test performed with RSSI somewhere between
-60 and -68, without antennas, but w/ high quality pigtails w/Bulk head N,
Pointing N connectors to each other.
Note: Re-tried
tests with antennas used, to increase RSSI (-50 to -60 db), but it did not
improve results.
Note: All tests done when in NStreme2 mode, using
two cards on each end.
Note: Both boards mounted in Mikrotik Plastic Large
Case (sweet cases) and using 18V (.8amp) via POE.
One thing that was really
odd... Mikrotik has a value for TX rssi and RX rssi. The
TX rssi was the exact RX rssi acheived at the otehr radio in all cases
in any slot, in any configuration.
However, the CM9 in the TOP Slot of
the 532 board consistently showed an average of 10 db worse TX RSSI.
(sometimes around -75 db). Swapping TX CM9s did not help. TX from the top
slot on either of the Mikrotik CPEs showed the same results. The
only way I was able to make the TX rssis the same on both CPEs simultaneously
was to set the BOTTOM port/CM9 on each Mikrotik to be the TX radio. This
indicated that the 532 board possibly might have a power problem to the top
slot. In this configuration, at 54mbps, RSSI was about -65 TX and RX
on both CPEs.
My conclusion of this experiment was that the
ideal configuration for a MIkrotik 532 board is with 10Mhz channels in
NStreme2 mode.
Because Spectrum efficiency is maximized,
Interference avoidance maximized, Cost low, and very little aggregate speed
benefit acheived by using the larger channel sizes.
My second conclusion was that the 532 router board
is inadequate, based on processor bottlenecks, to acheive higher speeds than 20
mbps aggregate throughput. (LAB test is best case
scenario!)
And if using 20Mhz channels or higher, I don't
see the point of using Nstreme2, as 1 CM9 in straight 802.11a mode on a 532
board has been tested to be able to pass about 14 mbps
aggregate.
Mikrotik's website claims that 35 mbps aggregate
can be acheived with Celeron 700Mhz CPU PCs. Although that is a grand
accomplishment at very low cost, there are significant disadvantages of
that configuration in real world deployments. Such as where do you put the
PC in a shared Tenant building, so it is close enough to the roof, so the COAX
to antenna is not going to loose valuable db, or where power is gotten
from, or how is it going to be rebooted by a customer if the power input is not
from customer's suite? I'm sure there are many places that Full Size PCs
could be appropriate to use, but its not going to be realistic for us, until
there is a 700Mhz Celeron able to be POE fed and mounted in an outdoor
style CPE box.
What this has done is brought to my
attention the value of products like Alvarion BH40/BH100s and Trango Atlas
PtPs, that can be taken for granted. In single radio designs, BH40s
usually can push 24 mbps with old 3.0 firmware, BH100 reported by some in the
greater than 40mbps ranges, and Trango Atlas PTP easilly pushes 36 mbps in most
deployments, using the same tests that I used above. So Mikrotik 532s
are not a replacement for my Trango backhauls
yet!
However, on a positive note, I liked the Mikrotik
Full Size CPE case, costing only $45, allowing extra room for cable splicing
boxes (to split POE to other radios fed off the Mikrotik's 2nd and 3rd ports)
plenty of places to tie down pigtails, and easy plastic to drill/make holes for
(non-circle) Bulk N-connectors that will not pivote when moving. I also
need to think hard that the Nstreme2 -10Mhz channel configuraton
might become the standard backhaul configuration to replace slower 10mbps
backhauls, doubling capacity in the same amount of spectrum as previous options.
Feedback from others desired.
Tom DeReggi
RapidDSL & Wireless, Inc IntAirNet- Fixed Wireless Broadband
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