Yep. We just covered this in our wireless theory RouterOS course last night! :)
* ----------------------------------------------------------- Dennis Burgess, CCNA, A+, Mikrotik Certified Trainer WISPA Board Member - wispa.org <http://www.wispa.org/> Link Technologies, Inc -- Mikrotik & WISP Support Services WISPA Vendor Member* *Office*: 314-735-0270 *Website*: http://www.linktechs.net <http://www.linktechs.net/> */LIVE On-Line Mikrotik Training/* <http://www.linktechs.net/onlinetraining.asp> The information transmitted (including attachments) is covered by the Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, is intended only for the person(s) or entity/entities to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient(s) is prohibited, If you received this in error, please contact the sender and delete the material from any computer. Kurt Fankhauser wrote: > I know first hand experience that if you stack 3 cards running 2.4ghz on a > RB333 that they will interferer with each other and you will have many > unhappy clients. > > Kurt Fankhauser > WAVELINC > P.O. Box 126 > Bucyrus, OH 44820 > 419-562-6405 > www.wavelinc.com > > > -----Original Message----- > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On > Behalf Of Eje Gustafsson > Sent: Tuesday, April 21, 2009 1:01 PM > To: 'WISPA General List' > Subject: Re: [WISPA] using multiple 5.3 cards in a Mikrotik > > Basically from own experience and testing. > > Two cards mounted side by side at a slight distance even if they are XR5 > cards suffers no to minimal problems between them and it goes for all cards > I seen. > > Two cards mount closely stacked on each other with just millimeter distance > do cause problems at times. Worst cases are the high power cards like for > example the XR5. In some instances the frequency transmission been majorly > separated yet the problem is there. It is almost like the preamped, premixed > signal is bleeding between the cards causing interference. But this is just > stipulations. > In testing by putting an alu foil sheet (put inside plastic sheet > protectors) between the cards seemed to cure the worst problems and at least > stop the constant association/disassociation problems. Never had a chance to > do check for RF errors and compare throughput data between this setup and > one where the radio cards where put in separate boxes. > > The issue seems far less common with the lower powered 5GHz cards (ie 100mw > or less). But I have not done a lot of testing there but also not heard any > issues complaints there where I heard plenty of people having issues with > trying to stick 3 or 4 5GHz high power radio cards in a single MT board in a > single metal/diecast outdoor enclosure. We try to talk people out of > building the 3 or 4 radio AP's with running the same frequency on all the > cards. We have however not seen this issue (or at least not caught the > obviousness) when doing multiple frequencies. Say put a 2.4GHz high power > card on top of a high power 5GHz card in a RB600 on one side of the board > and another 2.4ghz on top of a 5ghz on the second mpci stack in the RB600. > But on the RB333 and actually even the RB600 we seen issues doing 2 or 3 > 5GHz cards. Due to the nature of 2.4ghz (higher noise floor levels, used for > CPE connections etc) we have not been able to say ahh your problem there is > self interference between your cards in the unit. But since most people use > 5GHz for ptp backhaul with low noise floor we been able to pin point that > hey this link shouldn't have any problems and if we turn of one of the other > radio cards the trouble link has no troubles any longer your self > interfering on yourself inside your own box. > > A UFL connector can pickup signal from another UFL connector and create a > working solid link of the cards are no more then a few inches apart. I > tested this at numerous occasions. So RF bleeds from another radio could be > picked up by a UFL connector when the source is strong enough and just one > or two inches away. Since most cards have diversity built in to them the > secondary port by default will always be listening so this will of course > create a problem. > > With a MMCX connector I been able to pickup signal from an AP easily 20ft > away with a card with no antenna or pigtail plugged in to it (AP had > antenna). So looking at this using a radio with UFL as the main connector > and a MMCX as secondary could very well create even a bigger issue since the > MMCX is even better at picking up radiated signal then the UFL. > > Many people prefer the MMCX connectorized cards because they can use a > larger pigtail that has less cable loss.. But from what I understand the > lower cable loss on the pigtail is negated by the fact that the MMCX > connector on the radio has more connector loss then a UFL so a MMCX vs ufl > is plus minus zero in cable loss/connector loss. > > > -----Original Message----- > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On > Behalf Of Tom DeReggi > Sent: Tuesday, April 21, 2009 10:40 AM > To: WISPA General List > Subject: [WISPA] using multiple 5.3 cards in a Mikrotik > > I have read numerous discussions on problems regarding self interference > between two mPCI cards inserted in the same SBC, on same Freqs. Some > reporting need for 40Mhz of center channel seperation. > > These are the factors... > U.FL vs MMCX connectors > One vs two Antenna Ports on a single mpci card (for example will second > unused antenna port on card without pigtail hear noise. Does the second port > > need to be terminated?) > Proximity of mPCI slots to each other. (ADI/Lucaya side by side versus MT > 433 Stacked) > High power embedded amped vs low power cards. > Software thresholds vs not (min and max receive threshold and adapative > noise immunity) > Bleed over at card versus bleed over at antenna. (polarity won't help at > card's port) > Interference from Antenna port RF vs internal electronics generated RF noise > > (used to see this in PCs if HDD were to close to MB) > One manufacturer's card vs another's. > Receiver overload vs interference > > Unsubstantiated guestimates about this topic won;t really help because there > > are a LOT of variables contributing to the problem. > > MT433 or equivellent will most like work excellent if each card has a > different freq such as 2.4, 5.8, and 900. Unless the problem is Receiver > Overload. Where in that case maybe 2 CM9s could work better even if both on > adjacent channel 5.3? If interference is based on Antenna placement, well > thats easilly controllable by a field tech at time of installation. But what > > I'm concerned about is knowing that the radio system itself is made to be > non-ninterfering internally. From a remote management perspective, its going > > to be painful tracking which radio systems have to be how far apart in > channels to not interfere troubleshooting on-the-fly, without some baseline > stats defined a head of time. > > So this brings me to three questions of higher relevence..... > > 1) What do we need to do to guarantee that two cards can co-exist and be > used on adjacenet channels without interference at the radio card hardware > level (not including antenna placement factors that could allow intference) > > 2) Has anyone actually used a Spectrum Analyzer or Noise meter to actually > measure the RF bleed between to mounted cards? With accurate results of what > > the interference levels are? > > 3) Would WISP members be interested in contributing to a small fund to pay > someone to actually accurately measure the results for us? > > I'd like to specifically know for the 433 board. If using the higher quality > > MMCX w/ single antenna port cards (MT brand card), will 10Mhz of channel > seperation be enough, to get two 5.3Ghz channels operating correctly? > > Tom DeReggi > RapidDSL & Wireless, Inc > IntAirNet- Fixed Wireless Broadband > > > ----- Original Message ----- > From: "Eje Gustafsson" <e...@wisp-router.com> > To: "'WISPA General List'" <wireless@wispa.org> > Sent: Monday, April 20, 2009 4:39 PM > Subject: Re: [WISPA] is this router overloaded? > > > >> And 5.2 is not allowed for outdoor usage. So Franks unit is an indoor unit >> > > >> I >> would suspect he is suffering from multipath reflections. >> >> Besides on the radar stuff.. The way DFS is designed in MT it will never >> be >> able to get certified. First of it must continuously look for and detect >> radar not just when it first enable the interface. Secondly it at least >> did >> a horrible job in actually detecting radar signatures. >> >> Besides 5.2 is not part of the band you can use even with a certified >> radar >> detecting device. >> >> / Eje >> >> -----Original Message----- >> From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On >> Behalf Of Dennis Burgess - LTI >> Sent: Monday, April 20, 2009 3:32 PM >> To: WISPA General List >> Subject: Re: [WISPA] is this router overloaded? >> >> Part of the 5.2 band. All of the radar patters are in MT, just not >> certified. >> >> * ----------------------------------------------------------- >> Dennis Burgess, CCNA, A+, Mikrotik Certified Trainer >> WISPA Board Member - wispa.org <http://www.wispa.org/> >> Link Technologies, Inc -- Mikrotik & WISP Support Services >> WISPA Vendor Member* >> *Office*: 314-735-0270 *Website*: http://www.linktechs.net >> <http://www.linktechs.net/> >> */LIVE On-Line Mikrotik Training/* >> <http://www.linktechs.net/onlinetraining.asp> >> >> The information transmitted (including attachments) is covered by the >> Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, is intended >> only >> for the person(s) or entity/entities to which >> it is addressed and may contain confidential and/or privileged material. >> Any >> review, retransmission, dissemination or other use of, or taking of any >> action in reliance upon, this information by persons or entities other >> than >> the intended recipient(s) is prohibited, If you >> received this in error, please contact the sender and delete the material >> from any computer. >> >> >> >> >> >> Gino Villarini wrote: >> >>> 5180.....hmmm!!! >>> >>> Not to bust anyones head but you are using an uncertified device on an >>> illegal channel >>> >>> Sent from my Motorola Startac... >>> >>> >>> On Apr 20, 2009, at 3:20 PM, "Josh Luthman" >>> <j...@imaginenetworksllc.com> wrote: >>> >>> >>> >>>> Gino - Top right corner. >>>> >>>> Did the CPU just jump or has it casually been like that? >>>> >>>> I've never had 5 radios in any board, I don't know if that would >>>> cause a lot >>>> of usage or not. Most any MT box I've seen is <5% CPU. A lot of >>>> NAT as was >>>> mentioned would be the first place I'd look. >>>> >>>> Josh Luthman >>>> Office: 937-552-2340 >>>> Direct: 937-552-2343 >>>> 1100 Wayne St >>>> Suite 1337 >>>> Troy, OH 45373 >>>> >>>> Those who don't understand UNIX are condemned to reinvent it, poorly. >>>> --- Henry Spencer >>>> >>>> >>>> On Mon, Apr 20, 2009 at 3:14 PM, Kevin Neal <ke...@safelink.net> >>>> wrote: >>>> >>>> >>>> >>>>> Is this doing any NAT? Is connection tracking enabled? Do you >>>>> have all >>>>> unneeded packages disabled? We have a few RB600's out there and >>>>> they do >>>>> fine for the most part, we don't do any wireless on the 600's and >>>>> all of >>>>> them have the 564 daughterboard in them. >>>>> >>>>> -Kevin Neal >>>>> >>>>> >>>>> >>>>> -----Original Message----- >>>>> From: wireless-boun...@wispa.org [mailto:wireless- >>>>> boun...@wispa.org] On >>>>> Behalf Of Kurt Fankhauser >>>>> Sent: Monday, April 20, 2009 12:50 PM >>>>> To: 'WISPA General List' >>>>> Subject: [WISPA] is this router overloaded? >>>>> >>>>> I have a RB600 here that I've taken a screenshot of. No interfaces >>>>> are >>>>> bridged, everything is routed and I'm noticing some lag in the >>>>> traffic that >>>>> passes though this device during peak use. I suspect that the 41 >>>>> RIP routes >>>>> might have something to do with it as actual throughput isn't that >>>>> much >>>>> sometimes topping out around 8Mbps. Just want to hear from others >>>>> and if >>>>> there is any suggestions on how I might speed this up let me know. >>>>> CPU >>>>> usage >>>>> on it is around 40-50%. >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> Kurt Fankhauser >>>>> WAVELINC >>>>> P.O. Box 126 >>>>> Bucyrus, OH 44820 >>>>> 419-562-6405 >>>>> www.wavelinc.com >>>>> >>>>> >> >> >> >> > ---------------------------------------------------------------------------- > ---- > >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> >> > ---------------------------------------------------------------------------- > ---- > >> WISPA Wireless List: wireless@wispa.org >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ >> > > > > ---------------------------------------------------------------------------- > ---- > WISPA Wants You! 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