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Boro
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Linksys WRT54GS much better then RB112+Senao NMP-8602+ (FCC)

Mon Nov 27, 2006 8:31 pm

Recently I replaced my old Linksys WRT54GS with RB112+Senao NMP-8602+ (working as AP only) due to have top grade radio performance. Unfortunately the result is much worse than Linksys...
All of my clients has cards based on Ralink RT2560 (fixed to 5.5Mbit tx rate in driver - to increase output power), AP antenna is Interline 12dBi (horizontal polarization, omni, DC shorted, 1m of H1000 cable), network mode 802.11G (WPA2-PSK-AES).
Client signal levels seen by Linksys are -55 to -75dBm and the speed is quite reasonable but after replacing with RB/Mikrotik platform the performance degraded significantly - the fixed client tx rate seems not to work anymore (every client hopping over tx rates) and recieved client signals are -75 to -90dBm...Even without fixed rate Linksys reported much better signal levels...
I tried to limit tx rates on AP, change A to B connector etc but with no results.
WHAT IS GOING ON? Is linksys for $70 (cheap broadcom BCM2050 radio chip) is better than RB + new Atheros 5006X with "super" SENAO RF circuit for more than $200??
Maybe there is a problem with compatibility with DC shorted antenna or am I missing something??

Please, HELP!

P.S. Of course after back to Linksys everything works like before swap.
Last edited by Boro on Mon Nov 27, 2006 8:56 pm, edited 1 time in total.
 
matthias
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Mon Nov 27, 2006 8:56 pm

are you able to establish a connection?

take a look at your log file...
do you have 4-way-handshake timeout (15)?
 
Boro
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Mon Nov 27, 2006 9:01 pm

Yes, my clients have had a connection, but with bad performance and even some disconnects from time to time (only far users).
And yes I saw this message in log but not so frequently. Mainly I see 'excessive data loss' or somethig similar.

P.S. 'far users" means 1,5km - this is the biggest distance in my network so it is not very much...
 
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Equis
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Mon Nov 27, 2006 11:20 pm

Perhaps the increases sensitivity in the atheros is working against you.

I have seen in high noise environment this can happen.

In high noise I use the 10mhz channels or an older prism card.
 
Boro
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Mon Nov 27, 2006 11:33 pm

This is some idea but there is not so much interference on my channel (and overlapping channels)... and what about low client signal levels??
 
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Equis
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Mon Nov 27, 2006 11:35 pm

on Athros, interference will show as low signal level


:-)
 
matthias
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Mon Nov 27, 2006 11:36 pm

pls check with wpa (NOT wpa2) encription or for testing reasons without any encription.

We had/have Problems with Mikrotik AP and non Mikrotik CPE using WPA2

Before we also had Linksys WRT and WPA2 without problems...
 
Boro
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Tue Nov 28, 2006 12:10 am

I cannot test it without encryption because I have one antenna on the tower and all my client use WPA2...
I still can't understand why CLIENT tx rate change when it is fixed on the driver (with linksys it is always stable).
There is another problem: output power of senao nmp-8602+. It is 400mW version and I cannot achieve full power - I tried every combination - manual tx power, card rates, fixed rated, default etc even tried to set 30dBm as sugested on this forum but best signal level on client side is similar to Linksys@150mW

@Equis
Is noise threshold works with new atheros chipsets?

Is this important which connector on senao card I choose? or are they equal?
Last edited by Boro on Tue Nov 28, 2006 12:14 am, edited 1 time in total.
 
matthias
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Tue Nov 28, 2006 12:14 am

you can generate a virtual ssid with another type of encryption...

as we had problems like this, clients came and had signal betwenn 75 and 90 for about 10seconds and then lost connection...
 
Boro
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Tue Nov 28, 2006 12:22 am

Yes I have to try VSSID - maybe I'll swap it again before winter comes for good...

What about using it without encryption? what is the benefits to not using "buggy" WPA2? My clients can autenticate and mainly there was no problem with disconecting but with poor performance.
 
jo2jo
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Tue Nov 28, 2006 7:27 am

also check the antenna port A or B option...just to be sure you have it set to the same port as the U.FL connector is connected.

I would also strongly recommend swaping out that 8602 for a GOOD card, such as an R52, CM9 or best = SR2...

we have seen some issues with laptop clients to an 8602...really a trash card, made to be Cheap money-wise...i knew it was weird when i was getting a 400mW card for ~$40 :( sr2 and the others named are a world of difference when it comes to these "weird" issues
 
matthias
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Tue Nov 28, 2006 9:17 am

well - it´s new for me that wpa2 should be "buggy" :roll:

but i think even a bad encryption (like WEP) is better than nothing, because without enc. everyone could connect to your AP or could listen to the data sent over the air....
 
Boro
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Tue Nov 28, 2006 10:11 am

@matthias
I don't say that WPA2 is buggy. I said "buggy" because of what you say about problems with mikrotik WPA2 and mixed manufacturers...I have no problems with WPA2 and Linksys - everything works like a charm.

@jo2jo
I checked every comination of A and B connector and A and B antenna option.

AFAIK the 8602 card is one of the best miniPCI card with very good specyfication (sensitivity, power etc), comparable with SR2, but cheaper (about $90 in my country). Every WLAN shop recommend it as very good choice, better than CM9 and so on. Ofcourse they say that SR2 is best choice but the price is very high.
The problem is that I'm not sure that when I even buy SR2 my problem will disapear...
 
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normis
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Tue Nov 28, 2006 10:19 am

AFAIK the 8602 card is one of the best miniPCI card with very good specyfication (sensitivity, power etc), comparable with SR2
if you search this forum, you will find that based on user experiences, it is more like the worst card ever made ...
 
matthias
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Tue Nov 28, 2006 10:22 am

okay, i understand....

We also ran Linksys AP before and had no Problems with WPA2. But when integrating Mikrotik as AP and Linksys as Clients there was no good connection. With Mikrotik AP and Mikrotik Client it works fine.

Problem could be, that with Mikrotik WPA2 the "wpa capabilites are not enabled", but with Linksys they are...

I gave this Info to MT support, but it seems that they have no time for this atm...
 
Boro
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Tue Nov 28, 2006 1:46 pm

if you search this forum, you will find that based on user experiences, it is more like the worst card ever made ...
This is big suprise for me...but I prefer your practical experience than sellers one. So which card should I get to have top grade radio (for AP, 2,4GHz, 802.11g)? SR2? CM-9? R52? or other one? I want to have possibility to use at least 19-20dBm in the highest G rates (48,54) so probably SR2 is the only choice. Please advice.
I can choose form this offers:
http://www.cyberbajt.pl/index.php?i=grupa&id=13&idd=94
http://www.technologic.pl/produkty_moduly_radiowe.html

@matthias
what wpa capabilities you talking about?
My every client is non-Mikrotik (Ralink RT2560 cards) but I think I shoud work fine - users can authenticate and they have connection. What problems you have with mikrotik+Linksys client?
 
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normis
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Tue Nov 28, 2006 1:48 pm

So which card should I get to have top grade radio (for AP, 2,4GHz, 802.11g)? SR2? CM-9? R52?
yes, these all are very good
 
wildbill442
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Wed Nov 29, 2006 2:36 am

I can vouch for the SR2's and CM9's as being great cards. These are the only cards we use, well those and a few PRISM cards. We no longer deploy PRISM's due to their lack of support in RouterOS.

I've never tried the R52's.
 
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Wed Nov 29, 2006 2:45 am

The new R52 is much better than the CM9 - which is a very good radio, making the R52 a very excellent radio. We have replaced several CM9's with R52's and seen a huge jump in link quality.

For example one link about 1km with poor antenna aiming and trees in the way (due to mounting, antennas couldn't be aimed perfectly) with CM9's on each end was around -75 most of the time, rates usually at 36M/36M. CCQ was good and throughput was accepable.

One end of the link was damaged by a nearby lightning strike and its' associated power surge. Replaced WRAP2C+CM9 with RB112+R52, now signal is around -58 and rates are 54M/54M solid!!

R52 is HIGHLY reccomended by me. We no longer purchase CM9, because R52 is so much better!!

SR2/SR5 are also very good cards, if you need the higher power they are quality products and I reccomend them as well. Just keep in mind to use the lowest power that will work in any given situation, to prevent having too much noise.
 
maxfava
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Wed Nov 29, 2006 6:00 pm

Perhaps the increases sensitivity in the atheros is working against you.

I have seen in high noise environment this can happen.

In high noise I use the 10mhz channels or an older prism card.
normis
Is there a way to reduce the sensitivity on the receiver?
Have you check in your driver if there is this command supported by Atheros chip?
 
chucka
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Wed Nov 29, 2006 9:25 pm

Nickb,
R52 is HIGHLY reccomended by me. We no longer purchase CM9, because R52 is so much better!!

Was this dramatic improvement on a 2.4 or 5 GHz link. Are you using these on 2.4 GHz as an AP anywhere?
 
brasileottanta
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Thu Nov 30, 2006 11:24 am

What is my post ? ???
 
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normis
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Thu Nov 30, 2006 11:32 am

 
maxfava
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normis
Is there a way to reduce the sensitivity on the receiver?
Have you check in your driver if there is this command supported by Atheros chip?
 
brasileottanta
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Thu Nov 30, 2006 11:59 am

Where I violate the policy ? and isn't my volonty to violate ...I report a real problem !!!
 
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normis
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Thu Nov 30, 2006 12:01 pm

I report a real problem !!!
calling something s**t is not problem reporting.
is there a way to reduce the sensitivity on the receiver?
not in software. you can try to increase the cable length maybe :)
 
maxfava
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Thu Nov 30, 2006 12:05 pm

not in software. you can try to increase the cable length maybe
Sure but as you know it will reduce the TX power.
I'm trying to understand what kind of technics other company use to reduce interferences.
 
brasileottanta
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Sat Dec 02, 2006 1:10 pm

Boro ,

actually the card we use is a Zcom 622h b/g. Work fine and better then Senao . Have 23 db of max power , more sensibility.

We have a station with this card ,with -123 noise floor !!! With Senao 8602 Plus ( FCC ) in identical site we have -91 noise floor !!!

Bye

p.s. we test the sr2 today ....
 
Boro
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Sat Dec 02, 2006 10:49 pm

Today I tried my new SR2 with RB112. My problems like with 8602 disapeard. The recieving signal levels from clients are very good (even slighty better then thoose from linksys).
Now what I noticed:
1./The client cards hopping over speed rates (they have Tx Rate set to fixed 5.5Mbps in the driver, no problem with Linksys). What is wrong?
2./I cannot achieve full 802.11g throutput even when client antenna is 1m to the AP, the max is 1,4-1,5MB/s with CPU almost @ 100% (with linksys I can get 2,5MB/s and with framebursting even 3MB/s). There is no diffirence if I enable WPA2 or I leave it without encryption (probably AES encryption is done by atheros chipset). Is really RB112 that slow??
 
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Equis
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Sat Dec 02, 2006 11:46 pm

dont get 1m to the antenna

get you signal strength to about -60 (not -45) and try again.

Real world speed rb112 with r52 10mbps (with 10mhz wide channel) I have

Also, I dont like 802.11g, I always get faster because of less interference on 10mhz wide

You can't beat cm9/r52 to cm9/r52
Last edited by Equis on Sat Dec 02, 2006 11:52 pm, edited 1 time in total.
 
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Equis
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Sat Dec 02, 2006 11:50 pm

about the cm9 vrs r52 thing.

I have seen r52 is very good in rb112 - rb532 but in wrap its a few db down.
Strange but true :-)
 
Boro
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Sun Dec 03, 2006 1:40 am

@Equis

I tried diffrent distances and max speed was about 1,5MB/s (megabyte!!) so is about 12-13mbit/s . With Linksys WRT54GS at the same testing procedure I get 2,5MByte/s and with frameburst enable about 3Mbyte/s (with software WPA2 done by CPU!! and max cpu usage of ~30% !! with RB112 i can't get more then 12mbit/s without encryption - simple data forwarding....this isn't impressive performance or I have something wrong in my config).
Please anybody inform me what max speed do you get between RB112 and client card (not between two RB112!!). Please specify client card chipset and miniPCI card in RB.Thanks.
 
hebeda
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Sun Dec 03, 2006 10:22 am

i would suggest to install the latest ralink driver on the client side to increase Tx power and sensitivity ...

most rt2500 ralink cards come with quite old driver, the latest generic ralink driver will increase tx and rx ...

please find them here:
http://www.ralinktech.com/supp-1.htm

there are also big differences with ralink minipci/minipci-express cards, in general i suggest my costumer always gemtek 802.11abg or gigabyte bg clients cards with ralink chipset if ralink is a requirement.... beside that there are also highpower 802.11a ralink chipset cards from zinwell ...
MSI rt2500 cards are quite deaf and low power for instance ...

ralink chipsets have excellent x86 win CE 4.2 and 5.0 support ... which is the mainapplication of my costumers ...
 
brasileottanta
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Sun Dec 03, 2006 11:53 am

Today I tried my new SR2 with RB112. My problems like with 8602 disapeard. The recieving signal levels from clients are very good (even slighty better then thoose from linksys).
Now what I noticed:
1./The client cards hopping over speed rates (they have Tx Rate set to fixed 5.5Mbps in the driver, no problem with Linksys). What is wrong?
Boro , fix speed limit in RB112.

Also me , the problem disappered with SR2.

Bye
 
Boro
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Sun Dec 03, 2006 1:30 pm

brasileottanta, I can't limit speed by supported/basic rates in RB112 because I have 15Mbit connection and every user should achieve full speed if he is only one in the moment, so I must use high AP Tx Rate at least 36Mbit/s (I cannot use 802.11b only mode). Simultaneously client tx rate should have low to have high output power which is acceptably to max 5.5Mbit/s...
It would be great if I can set client cards to 'Auto' and force them FROM AP SIDE to use selected and fixed Tx Rate without limiting the AP Tx Rate (tx rate from AP and client card is independent!)

hebeda, I use only generic ralink driver and most of my clients has new releases.
 
taloot
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Sun Dec 03, 2006 9:38 pm

8602 shouldnt be supported by mikrotik anymore
the worst mini-pci in the world and ever be made
no support from there side @ all

SENAO they should care about wireless phones and dont play with wlan's ;)
 
hebeda
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Sun Dec 03, 2006 11:35 pm

go for sr2 or z-com xg-622H , both have much better sensitivity ... both use AR5004G chipset ...
 
Boro
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Mon Dec 04, 2006 12:54 am

Guys the problem with RB came back, but now the problem isn't regarded to signal level (the levels on both sides are perfect) but it seems there is compatibility problem with Mikrotik and Ralink RT2560 chipset when using WPA/WPA2 AES.

Here are tests I made usinb Mikrotik bandwidth tool (all with RB112+SR2 as AP):

1./Ralink RT2560 client card, WPA/WPA2 AES
AP->user ~300kbit/s !!
user->AP 5-6Mbit/s

2./Ralink RT2560 client card, no encryption

AP->user 5-6Mbit/s
user->AP 6-7Mbit/s

3./ TP-Link (atheros 5211) clent card, WPA2 AES or no encryption (no diffirence in performance)

AP->user 5-6Mbit/s
user->AP 6-7Mbit/s

4./ Intel 2915ABG built in my laptop, WPA2 AES or no encryption (no diffirence in performance)

AP->user 5-6Mbit/s
user->AP 12-14Mbit/s !!


This tests proved that there is some incompatibility with Mikrotik and Ralink chipset when using WPA/WPA2 AES (no problem with Linksys at all). The weird thing is great performance of Intel 2915abg chipset (I do this test 2 times, but comparing to Linksys 3Mbyte/s it isn't so much...).

Any comments?? anybody have same problems with Ralink RT2560 and WPA2??
 
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normis
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Mon Dec 04, 2006 10:58 am

RouterOS does not support Ralink at all. I wonder how you even got it recognized, let alone do some transfer over it.
 
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janisk
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Mon Dec 04, 2006 11:15 am

side note to normis:
no, he used RM112 with SR2 card as AP and used different clients to connect to AP (RB112 with SR2)


and no boro:

when performing BT do it from client to client (wireless client -> AP -> wired client) because RB112 has weak CPU and if you set it to recieve or send packets - results always will be poor. so no surprise there.

and if you can look up uldis (another MT here) test where he tested RB112 you could compare with his results.
 
Boro
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Mon Dec 04, 2006 11:16 am

normis I wrote clearly that Ralink/tplink/Intel 2915 was CLIENT CARDS working with RB112+SR2 as AP....

EDIT: janisk was faster :)

and yes I noticed that AP->client is limited mainly by cpu performance but there was no time to repeat tests yesterday. Today I will repeat it with wired client as a source.

Anyway this isn't my point...my problem is all my clients has Ralink RT2560 based cards and I can't swap AP to Mikrotik because this cards do not work propetly with it....Maybe there is some way to fix this issue?
Last edited by Boro on Mon Dec 04, 2006 11:26 am, edited 1 time in total.
 
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janisk
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Mon Dec 04, 2006 11:25 am

normis I wrote clearly that Ralink/tplink/Intel 2915 was CLIENT CARDS working with RB112+SR2 as AP....
someday we all wont be able to read properly :D

ok, now, how about testing through that RB112 not to or from it?

btw, WPA2 is done in SR2 card - so there should NOT be any diff.
 
Boro
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Mon Dec 04, 2006 11:32 am

janisk, there is no big problem when using atheros or intel based client cards - real transfer form/to FTP wired serwer is about 1,5Mbyte/s (maybe it is not perfect but sufficient for now...). BUT when using Ralink RT2560 based cards (diffrent vendors: MSI PC54G2, Gigabyte WPKG and some Sparklans) the AP->client card is about 200-300kbit/s (uplink is ok)...no problem without encryption
 
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normis
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Mon Dec 04, 2006 11:39 am

as the encryption is done in the card on atheros cards, but in software for other cards (like your ralink), wouldn't this automatically answer your question ?
 
Boro
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Mon Dec 04, 2006 12:42 pm

no, because Ralink do WPA2 encryption by the hardware
no, because using the same cards I can achieve ~3Mbyte/s with LinksysWRT54GS
and no, because software WPA2 isn't worse than hardware - Linksys do WPA2 by the software with great performance and compatibility.

So, you can ask why I want to swap this "perfect" Linksys to Mikrotik?
because Linksys radio has medium quality radio parameters (sensitivity, output power) so I can't connect very far clients or clients behind the trees etc AND I think that Atheros chipset can carry a lot more users at the same time then broadcom BCM2050 with high performance - my inet connection is 15Mbit/s.
 
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normis
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Mon Dec 04, 2006 12:49 pm

after you see these results, are you still sure about it ? if the traffic goes `throgh` the router, the router doesn't do anything with it. so there is no difference whether it's encrypted or not, because router simply doesn't look at it. My bet is still on the endpoint cards/drivers.
 
Boro
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Mon Dec 04, 2006 2:10 pm

this is my misgiving too. I will send this problem to Ralink and maybe they will fix it with new driver, if not I'll think about client card swapping...
Have you guys any experience with TP-Link WN551 (atheros 5211) as client cards? They are reasonable priced and maybe it is interesting choice?
 
spire2z
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Tue Dec 05, 2006 4:06 am

Personally I would test the clients with AUTO rate setting. I think it's possible that the reaon that they work set fixed on 5.5 mode is that there is something weird with the way Linksys handles rate. I experienced a simmilar thing once when a setting like that worked with a low budget equipment when really the setting is not correct in industry standard terms. You can normaly get away with fixing rate on point to point links and I never had much success with fixed rate clients on multipoint setup. For example just because the client gets good enough signal in testing when another user is hammering the system the rate would drop to lower rate because of the interferance from the other users traffic especially upload traffic. If the rate does not drop you will experience far worse connection from packet loss. Even if by some mirricle the Linksys did perform better radio wise in some circumstance there is just NO WAY it has the features or reliabillity you need to provide a commerical WISP service in my opinion!
 
Boro
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Tue Dec 05, 2006 10:55 am

The reason why I use fixed client tx rate is the output power. 5.5Mbit/s is the highest rate with still acceptable power (in my cards) and simultaneously enough low for near and far clients. If i set clients to 'auto' they jump over the high rates (18Mbit and higher) and recieving level seen by Linksys is very low and uplink( client -> AP) performance is very poor. If I force client txrate to one of the lowest rates the output power increase considerably and the performance is good (ofcourse limited to selected mode abilities, but upling speed isn't so critical - my inet connection uplink is 800kbit/s).
Another advantage of fixed rate is that every client transmit on the same speed, modulation etc and AP don't have to switch over the rates every time it listen another client and it has impact to performance.
 
spire2z
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Wed Dec 06, 2006 2:51 am

That could confirm my theory? You were using a unique setting to cope with the poor performance of the Linksys product. I would really give auto a go on the clients and see if the better sensitivity and performance of say Ubiquity and a RB can overcome that. You might be suprised. Also be sure to use the newest Mikrotik software version on the RB. I found such better client handling since a few versions ago.
 
Boro
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Wed Dec 06, 2006 10:41 am

Ofcourse linksys performance (sensitivity in this case) is considerably worse than SR2, but output power of client card is another thing. Sure, with SR2 I can use auto because if client card choose higher tx rate (lowest power) SR2 will be still able to work with this low level (ofcourse if there is low level of interference from another networks). But if client is very very far the sensitivity will be not sufficient and we will need more power again. So solutions are: lower the tx rate to get higher power or buy another card with better power...

Anyway, the sensitivity isn't my problem anymore. There is incompatibility with my client cards and Mikrotik. Probably this was the reason of problems with Senao 8602 too. I sent email to Ralink support, but only advice was to install "new" driver (09/2006) which I already tested...
It seems if I want move to Mikrotik platform I have to swap all client cards to Atheros based...
 
brasileottanta
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Tue Dec 12, 2006 4:00 pm

I'm frustrated :-(

I install the new bts with sr2 , but no change !!! Same antenna , same cable , same position : with a stupid linksys , my client connect fine ( also client distant 3/4 km .. ) , with a rb112 and 1 sr2 nothing.

I test also a 50m from antenna : linksys ping 3 ms , sr2 ping 100/240ms !!! What's wrong ? what's happen ?
 
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janisk
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Tue Dec 12, 2006 5:13 pm

same channel, same no configuration (minimum = ssid, band, frequency ip)? :roll:
 
brasileottanta
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Tue Dec 12, 2006 5:58 pm

same channel, same no configuration (minimum = ssid, band, frequency ip)? :roll:
Yes :-( equal everithigs ....

Now I change other things .. but ....
 
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janisk
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Wed Dec 13, 2006 2:53 pm

and what is signal strength - is I remember - there is performance decrease if it is too good (above -40 -45 dBm
 
brasileottanta
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Fri Dec 15, 2006 7:18 pm

Hi ,

the only difference with 2 bts is the enclosure. One is in plastic , one in alluminium .


Now , I test a SR5 with RB532 and the noise floor is -95 ( no other wireless net in area ) . Why is low ? .


Bye

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