The V3 code on the WAR boards is compatible 802.11a but I would not
call it "vanilla".  This driver is tweaked for performance and we can
get about 150 mbps total throughput on the 533 MHz boards.  With
compression and Turbo mode and using a radio repeater (input radio and
output radio) we have clocked 80 mbps through the unit.

We find the biggest advance we have made though, is the use of 5 MHz
and 10 MHz channels.  Although people have this huge desire for the
fastest possible speeds we actually see that most people do not even
have 10 mbps pipes to the Internet and thus a backbone that can
deliver 40 mbps is quite wasted.

Using smaller RF channels you can fit 11 Access points on a single
tower at 2.4 GHz and they will not really interfere with each other
plus you can still achieve 10+ mbps to the customer from each AP.  Of
course you should maintain proper antenna separation and try to keep
adjacent radios a few channels apart.

Lonnie


On 6/22/06, Stephen Patrick <[EMAIL PROTECTED]> wrote:


Hi Charles,

Well I can't comment on what software Alvarion uses - they of course can.
Sure we can share more information with people on our solution.  It uses a
passively-cooled, 1GHz CPU in outdoor grade housing with a powerful
architecture capable of driving 5 radio cards with over 200Mbps bridged
wireless-ethernet throughput demonstrated in P2MP configuration.
It has both 10/100 POE and Gig-E ports.  Several users tell us that's a
pretty unique solution on the market just now.

The Routerboards are great, but are optimised for a completely different
cost/performance point. Apples and Oranges.
You are right that on slower platforms, the "software overhead" of Nstreme
actually reduces net throughput, i.e. CPU is limiting and the extra
processing slows things down.  On our boxes the opposite is true, the radio
cards are the limiting factor and we can extract the very last bps/pps from
them.

Re: your comment about MT's documentation, we have our own user manuals for
customers, to support our product range.
Nstreme "repackages" the data into frames, which with polling greatly
improves P2MP performance as well as the huge improvements seen on P2P
links.  This is reality not myth.  I'd strongly recommend trying the
solution "for real" rather than "believing the vendor" (us in this case).
Coupled with a MT-based CPE (we have our own also, now at pretty aggressive
prices in volume) you have major benefits in a P2MP environment and the
security improvements that are inherent with the "proprietary extension"
nature of Nstreme - you can't see or connect to it using a WiFi or "Brand X"
client.
I am sure other users can comment on the latest StarOS versions, but AFAIK
that uses "plain vanilla" 802.11a with the Atheros WiFi extensions.  That
isn't the same, MT's Nstreme adds a completely new layer, with "small packet
performance" being a major benefit, as other users commented.  I think
Lonnie is on this list and can comment on the latest in StarOS/StarVX.

Best regards

Stephen

-----Original Message-----
From: Charles Wu [mailto:[EMAIL PROTECTED]
Sent: 23 June 2006 00:49
To: 'WISPA General List'
Subject: RE: [WISPA] frame size and fps - was OT: about 70Mbps for under $
6K






Screenshot of NMS from full-speed lab testing, 83Mbps UDP traffic with ~20%
CPU load
http://www.cablefreesolutions.com/radio/HPR%20lab%20testing%20UDP.png
Screenshot of NMS from full-speed lab testing, 74Mbps TCP/IP traffic with
~20% CPU load
http://www.cablefreesolutions.com/radio/HPR%20lab%20testing%20TCP.png

Hi Steven,

Wouldn't it be funny if the Alvarion product was actually Mikrotik Nstream?
<ducking>

On or offlist, I am curious if you'd be willing to share your settings
required to achieve this (both hardware and software)

38 Mbps TCP throughput on a 20 MHz channel w/ 54 Mb air rate is quite
impressive, and I would like to try to duplicate these results if possible
(I'd more than happy to share our testing scripts, platform, etc)

Thus far, our Mikrotik testing has been limited to routerboards, and it
seems that the limited processing power on the routerboard prevents us from
seeing the benefits Nstream (our current testing w/ Nstream has actually
shown decreased performance as opposed to just straight WDS bridging, but we
are by no means Mikrotik experts)

That said, compared to the rest of Mikrotik, the documentation surrounding
Nstream is a bit sparse -- looking at what is available, it seems to me that
most of the performance gains of Nstream are achieved through "fast-framing"
-- e.g., it looks like Nstream utilizes combination of timing modications
and frame concatenation to increase throughput by transmitting more data per
frame and removing interframe pauses.  My understanding of this is that
Nstream is bundling several frames (depending on settings, default of 3200
looks like it has enough space for 2 frames) together into a single larger
frame; in the case of 2 for 1 bundling, this would essentially halve the
amount SIFs and ACKs that the protocol has to transmit for a given payload

So a few observations/questions for either you (or maybe John will speak
up?)

1. Nstream has the ability to set this framing concatenation mechanism (via
framer-policy attribute) to none -- if this is set to 0, will there be any
performance differences b/n Nstream and "standard WiFi"

2. What are the parameters for the framer-limit setting (if 3200 lets me
concatenate 2 packets, wouldn't 5800 work even better as I would be able to
concatenate 3 packets and eliminate additional overhead?)

3. While frame concatenation does improve throughput for low density
situations -- in high density PtMP situations, we've seen multiple small
packet streams basically bring polling-based systems to their knees -- is
there any data, testing, experiences on this side w/ Nstream?

4. What about bursting? The DIF is another major point of "waste" in 802.11
systems.  Is the DIFs automagically eliminated due to the fact that a point
coordinator is being implemented or is this done via the burst-time command
under the wireless interface?  If so, is there a way to turn this off for
point-to-point situations to achieve better performance?

-Charles

P.S. -- Our testing of StarOS using WDS bridging on the 266 MHz IXP Boards
is yielding ~36 Mb of TCP throughput on a single 20 Mhz channel (this is w/
bursting & frame concatenation turned on)


-------------------------------------------
CWLab
Technology Architects
http://www.cwlab.com



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Lonnie Nunweiler
Valemount Networks Corporation
http://www.star-os.com/
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