http://www.cwnp.com/bbpress/ CWNP Forums en-US Sat, 04 Feb 2012 05:14:13 +0000 http://bbpress.org/?v=1.0.2 q http://www.cwnp.com/bbpress/search.php http://www.cwnp.com/bbpress/topic.php?id=6995#post-26533 Fri, 03 Feb 2012 18:09:46 +0000 Wlanman 26533@http://www.cwnp.com/bbpress/ <p>From the wavelength point of view, that is enough. The problem is the gain (and output power). </p> <p>The RF being output from each one may saturate the others radio, cutting down the others reception, or even damaging its circuits. The radios might also never get past CCA from a ED (Energy Detect) point of view.</p> <p>How much power are the radios, less the antennas, putting out ? </p> http://www.cwnp.com/bbpress/topic.php?id=6995#post-26532 Fri, 03 Feb 2012 17:23:23 +0000 garybr 26532@http://www.cwnp.com/bbpress/ <p>i have two 9 dbi omni atennas at 5 GHz one is on channel 153 the other antenna is on channel 165 they are at the same height and are about one foot apart is this workable or do i need to move them ??</p> <p>thanks </p> http://www.cwnp.com/bbpress/topic.php?id=5893#post-26531 Fri, 03 Feb 2012 12:45:51 +0000 Wlanman 26531@http://www.cwnp.com/bbpress/ <p>Yeah. I know :(</p> <p>Maybe not a good candidate for the book, but in some contexts it might help.</p> <p>I hadn't thought of it before, but similar to IEEE (2007) we could use LSTA (2007), or even LIEEE 802.11(2007).</p> <p>Reductio ad absurdum </p> http://www.cwnp.com/bbpress/topic.php?id=5893#post-26530 Fri, 03 Feb 2012 12:09:48 +0000 Marcus Burton 26530@http://www.cwnp.com/bbpress/ <p>The problem with such a term (i.e. LSTA) is that its reference is constantly evolving. In 2007, an LSTA would have been 802.11b. In 2009, 802.11g. In 2013, 802.11n. And so on. :) </p> http://www.cwnp.com/bbpress/topic.php?id=6990#post-26529 Fri, 03 Feb 2012 12:04:18 +0000 Kevin FranMan 26529@http://www.cwnp.com/bbpress/ <p>The question is there but is "not answered" </p> <p><a href="https://supportforums.cisco.com/thread/2003194" rel="nofollow">https://supportforums.cisco.com/thread/2003194</a></p> <p>This is where I read that ACLs on the WLCs causes a performance hit. Also the thought on trying to use private vlans.</p> <p>I think the private vlans would be the solution but it seems like they are kind of limited in function on the 6500, as you can't configured trunks correctly (this feature is on 4500s though). Also since the WiSM auto configures it's own ports you can't apply the changes needed to ports.</p> <p>PACL would be a good option for layer 2 ACLs but again you can't apply them to any ports because the WiSM doesn't have any physical ports. </p> <p>I can't think of anyway in the 6500 to block layer 2 traffic. My SE tells me that all the layer2 traffic runs through the sup card and you can apply a L2 ACL there but it would require an ACL entry for every client. He tells me there isn't dynamic way to do it. So that isn't going to work. I am far from a 6500 expert but this SE is a CCIE R&amp;S guy. I'd think you could make an ACL to only allow traffic to and from the router's MAC and then deny all? I'll have to dig in to it some more. The SE is going to ask his resources about this problem. I am not totally sure that the two WLCs on the WiSM1 don't talk directly, seems odd the traffic would go up to the sup and then come back.</p> <p>Oh well. Good news is the 7.2 code on the WiSM2 is going to support 1000 aps. So I'll be able to just put all the APs on one WLC and the P2P will work. Not sure how long it will be before I'll have more than a 1000 aps per site. It also doesn't help me at my WiSM1 sites.</p> <p>thanks for the help </p> http://www.cwnp.com/bbpress/topic.php?id=6991#post-26528 Fri, 03 Feb 2012 11:55:10 +0000 Marcus Burton 26528@http://www.cwnp.com/bbpress/ <p>Everything I've heard agrees with Wlanman. The WFA was initially trying to push the best security practices to the market, but business needs always squash tech purists. Companies just aren't willing to spend money to upgrade legacy client devices, and mfg's have to respond to customer needs. </p> http://www.cwnp.com/bbpress/topic.php?id=6994#post-26527 Fri, 03 Feb 2012 11:48:53 +0000 Wlanman 26527@http://www.cwnp.com/bbpress/ <p>The practice with AP's is meant to help cement the concepts regarding wireless into your thinking. <u>Nothing</u> to do with learning <em>any</em> manufacturers gear. If that were your goal, I would have been more likely to specify Enterprise, rather than SOHO.</p> <p>It is exactly the "vendor neutral" idea. You learn what is generally available and how different manufacturers do things. Connecting up the clients under all the different situations helps you learn something about debugging WLAN problems, and I believe help you learn the technolology better. </p> <p>When you get to the exam, you have some memory to fall back on - "Oh Yeah - I remember how that worked" or "Yeah. I know why that is."</p> <p>I am one of the biggest "vendor neutral" advocates around. As I'm sure Marcus would agree.</p> <p> Wlanman </p> http://www.cwnp.com/bbpress/topic.php?id=6994#post-26526 Fri, 03 Feb 2012 10:33:04 +0000 Kevin Sandlin 26526@http://www.cwnp.com/bbpress/ <p>Alan is generally correct. CWTS is not positioned or required as a pre-req to CWNA. For someone brand-spanking-new to networking, yes, you might feel more comfortable starting at CWTS. But CWNA is meant as the starting place for those already in computer networking, either by experience, other certs (CCNA, Net+) or both.</p> <p>As to configuring APs, no, you don't have to know how to config any vendor's APs for CWNA; however, you will learn and need to know what it means to configure an AP's power settings, security, channel, etc. Those and many other settings are relevant no matter whose AP you're installing and configuring, and those are the things CWNA teaches you. </p> http://www.cwnp.com/bbpress/topic.php?id=6994#post-26525 Fri, 03 Feb 2012 05:40:40 +0000 Alan 26525@http://www.cwnp.com/bbpress/ <p>While I respect and agree with most of wlanman previous post, I dont totally agree that you need to configure APs...this is a vendor neutral exam after all.</p> <p>Yes you can pass CWNA without CWTS, I did. If you have a good RF background and feel comfortable with the CWNA content then go for it. </p> http://www.cwnp.com/bbpress/topic.php?id=6990#post-26524 Thu, 02 Feb 2012 20:46:48 +0000 dave1234 26524@http://www.cwnp.com/bbpress/ <p>Kevin</p> <p>Don't know if you've tried the following forum:</p> <p><a href="https://supportforums.cisco.com/community/netpro/wireless-mobility/begin-wireless" rel="nofollow">https://supportforums.cisco.com/community/netpro/wireless-mobility/begin-wireless</a></p> <p>You can often get a reply literally within minutes. They really, really know their stuff. One of the guys from this forum ( George Stefanick ) has put up some excellent posts there. George has an incredible knowledge of Cisco Wireless gear and is very friendly. </p> <p>I read over every post each day and keep a word document with the weblink as well as key points from each post. My little brain is buzzing by the end of the day, but it's all good stuff. Some nights if there is a really interesting problem, I can barely get to sleep. Pretty sad really, but there you go. The life of a nerd. Depending on time zones etc, you can often "see" a problem being resolved almost in realtime as the various people go back and forth. </p> <p>If you haven't already done so, check them out. You won't be disappointed. They've won a number of awards for the forum.</p> <p>As always with ACLs…location, location, location</p> <p>Dave </p> http://www.cwnp.com/bbpress/topic.php?id=6994#post-26523 Thu, 02 Feb 2012 20:26:30 +0000 Wlanman 26523@http://www.cwnp.com/bbpress/ <p>It is very likely that you could pass, if you are good at studying. But I wouldn't try it unless you have at least configured several AP's (even SOHO) with just about <u>every</u> option avilable. And connected to them with a variety of client devices with each option too.</p> <p>A lot of people, including myself, passed the CWNA before CWTS ever existed - in any form.</p> <p>It is my <em>personal</em> belief that the CWNA became easier for a while - the details seemed like they were shifted around between exams somewhat.</p> <p>However, the technology is a lot more complicated now. Back then, 802.11n was only an industry wet dream. There was no MIMO, WMM, PSMP, SMPS, guard interval differentiation, or much talk about Mesh.</p> <p>Other than that, RF requirements (other than that used in describing the advantages of MIMO) look pretty much the same - be sure you really understand power and attenuation from a dBm perspective- no micro-volts/meter here.</p> <p>One big hint, is that it's not an official prerequisite to the CWNA. Once you can reliably get 90-100 %'s on all the online practice exams (w/o memorizing the questions and answers) you should think about taking it. </p> http://www.cwnp.com/bbpress/topic.php?id=6994#post-26522 Thu, 02 Feb 2012 18:55:44 +0000 eefrej@yahoo.com 26522@http://www.cwnp.com/bbpress/ <p>Hi all,<br /> how difficult would it be to pass the CWNA exam without being CWTS certified? is it feasible? i am new to this with a good RF background? </p> <p>Thanks </p> http://www.cwnp.com/bbpress/topic.php?id=6990#post-26521 Thu, 02 Feb 2012 17:44:36 +0000 Frans 26521@http://www.cwnp.com/bbpress/ <p>If peer to peer unwanted appears to work in intercontroler scenario's you should have the upstream component decide (ACL). </p> http://www.cwnp.com/bbpress/topic.php?id=6990#post-26520 Thu, 02 Feb 2012 15:13:51 +0000 Kevin FranMan 26520@http://www.cwnp.com/bbpress/ <p>Thanks for the link Frans. At least I won't have to worry about the broadcast anymore. Still need to figure out how to block peer to peer communication for security purposes. </p> http://www.cwnp.com/bbpress/topic.php?id=6993#post-26519 Wed, 01 Feb 2012 21:26:45 +0000 dave1234 26519@http://www.cwnp.com/bbpress/ <p><a href="http://www.msnbc.msn.com/id/46211081/ns/technology_and_science-security/" rel="nofollow">http://www.msnbc.msn.com/id/46211081/ns/technology_and_science-security/</a></p> <p>The next generation will infect your computer while it's still sealed in it's box on a shelf in Best Buy.......</p> <p>Dave </p> http://www.cwnp.com/bbpress/topic.php?id=6174&page=3#post-26518 Wed, 01 Feb 2012 20:57:28 +0000 dave1234 26518@http://www.cwnp.com/bbpress/ <p>P 484 last paragraph. Six lines down. "Figure 11.40" should read Figure 11.39</p> <p>Dave </p> http://www.cwnp.com/bbpress/topic.php?id=6139&page=2#post-26517 Wed, 01 Feb 2012 20:39:58 +0000 dave1234 26517@http://www.cwnp.com/bbpress/ <p>P349 last paragraph. Lines 3 and 4:</p> <p>“….MCS index 1 and 8 have the same data rates as 5 and 11 ). </p> <p>Could be misinterpreted.</p> <p>Although MCS rates 1 and 8 are the same ( 13/14.4 Long/Short Guard Interval ) and 5 and 11 are the same ( 52/57.8 ), they are not equal to each other.</p> <p>Dave </p> http://www.cwnp.com/bbpress/topic.php?id=5893#post-26516 Wed, 01 Feb 2012 18:08:01 +0000 Wlanman 26516@http://www.cwnp.com/bbpress/ <p>It's been a while since I've suggested any new words, but here is one that I think is good enough for the industry, as a whole, to start using. </p> <p>It doesn't show up in any of the 100 M of IEEE files that I have, but it probably should.</p> <p>The entry ? <strong> LSTA</strong></p> <p>"Any legacy STA device that does <strong>not</strong> support 802.11 <strong>n</strong>" .</p> <p>Of course the alternative claim could be made that everything will be "n", so why bother - well, for the same reason the WEP WLAN's still exist. </p> http://www.cwnp.com/bbpress/topic.php?id=6986&page=2#post-26514 Wed, 01 Feb 2012 16:42:24 +0000 Wlanman 26514@http://www.cwnp.com/bbpress/ <p>Look on the net for the "MultiPing" application program. Download the trial version, and install it.</p> <p>It will give you a visual display that will <u>show</u> you when the problems really occur. Much handier and informative than looking at Ping log files.</p> <p>I often use the licensed version, and it does a very good job. </p> http://www.cwnp.com/bbpress/topic.php?id=6990#post-26513 Wed, 01 Feb 2012 16:07:10 +0000 Frans 26513@http://www.cwnp.com/bbpress/ <p><a href="http://www.cisco.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch2_Arch.html#wp1028269">BC/MC behavior explained</a></p> <p>You can configure it from the UI. </p> http://www.cwnp.com/bbpress/topic.php?id=6988#post-26512 Wed, 01 Feb 2012 15:52:56 +0000 Frans 26512@http://www.cwnp.com/bbpress/ <p>Hi Alan,</p> <p>RRM works with patch antennas. Basically RMM consists of three components: Dynamic Channel Assignment, Transmit Power Control and coverage Hole Detection. TPC algorithms' function is to achieve coverage by adapting AP TxPower in such a way, that they surround themselves with 3 other APs at a certain threshold. This also works with semidirectional antennas. Keep in mind in your design that a patch can generate a strong signal in a certain direction. </p> http://www.cwnp.com/bbpress/topic.php?id=6981#post-26511 Wed, 01 Feb 2012 15:37:52 +0000 JamesFrancisco 26511@http://www.cwnp.com/bbpress/ <p>Thanks for the advice and the tip on remembering channel frequencies! I actually just started playing with AirMagnet, but haven't gotten too deep into it yet. </p> http://www.cwnp.com/bbpress/topic.php?id=6986&page=2#post-26510 Wed, 01 Feb 2012 15:24:17 +0000 Frans 26510@http://www.cwnp.com/bbpress/ <p>didn't show up as nice as I had it lined up. Bottom line, is it normal to get up to 97% misses on g/n ?<br /> Maybe I have been focussed more on auth, eap and voice rather than 11n data frames, I hope someone can shed a light on this. </p> http://www.cwnp.com/bbpress/topic.php?id=6986&page=2#post-26509 Wed, 01 Feb 2012 15:15:41 +0000 Frans 26509@http://www.cwnp.com/bbpress/ <p>Hereby some stats on part of the sniffer traces. Almost all Acks are showed, so the number of data frames should be 2x the nr of Acks for a RA. Especially g/n misses are massive &gt; 90% at some days.<br /> Used the following filters:<br /> wlan.ra == 58-94-6B-7E-E2-64 and wlan.fc.type_subtype==0x1d and wlan.fcs_good==1<br /> wlan.addr == 58-94-6B-7E-E2-64 and wlan.fc.type_subtype==0x2c and wlan.fcs_good==1<br /> wlan.addr == 58-94-6B-7E-E2-64 and wlan.fc.type_subtype==0x28 and wlan.fcs_good==1<br /> wlan.addr == 58-94-6B-7E-E2-64 and (wlan.fc.type_subtype==0x28 || wlan.fc.type_subtype==0x2c) and wlan.fcs_good==1 and wlan.fc.retry==1</p> <p>Do you get as many misses on the 2.4 GHz g/n ?</p> <p>Date time type Acks Null QoS-Data Miss% Data retry %</p> <p>27-jan 18:31 a 115 48 124 25 15<br /> 28-jan 10:35 a 215 70 264 22 1<br /> 28-jan 20:04 a 3871 3390 1321 39 8<br /> 29-jan 10:58 a 1807 1467 1076 30 18</p> <p>26-jan 10:47 an 231 56 219 40 38<br /> 26-jan 11:02 an 228 90 222 32 28<br /> 26-jan 18:52 an 607 248 758 17 18<br /> 27-jan 10:42 an 578 89 165 78 16<br /> 27-jan 15:53 an 254 90 224 38 31<br /> 28-jan 10:25 an 148 45 229 7 36<br /> 28-jan 12:41 an 12082 6325 17959 0 12<br /> 28-jan 13:04 an 8461 3912 12892 1 16<br /> 28-jan 14:16 an 7808 2736 7303 36 3<br /> 28-jan 20:09 an 2571 2233 908 39 7<br /> 29-jan 0:13 an 10788 1895 17830 9 6<br /> 29-jan 10:39 an 614 556 229 36 17<br /> 29-jan 10:45 an 1213 936 1099 16 27<br /> 29-jan 10:50 an 1107 842 822 25 21<br /> 29-jan 11:03 an 1273 1003 969 23 20<br /> 29-jan 14:28 an 2813 1914 2065 29 23<br /> 29-jan 14:37 an 4809 1312 4700 37 14</p> <p>25-jan 20:41 b 15663 0 27716 12 10<br /> 25-jan 20:44 b 542 42 997 4 3<br /> 29-jan 14:58 b 4734 95 8944 5 2</p> <p>27-jan 18:25 g 139 10 236 12 1<br /> 28-jan 13:41 g 8707 755 12863 22 5<br /> 28-jan 13:49 g 5595 589 7763 25 3<br /> 29-jan 14:56 g 3853 526 6321 11 1</p> <p>24-jan 20:01 gn 9972 24 804 96 49<br /> 25-jan 19:50 gn 2643 106 179 95 100<br /> 26-jan 10:21 gn 250 40 25 87 8<br /> 26-jan 18:52 gn 5729 35 280 97 71<br /> 26-jan 22:00 gn 2990 154 4047 30 20<br /> 27-jan 10:47 gn 490 32 67 90 2<br /> 27-jan 10:52 gn 400 32 53 89 11<br /> 27-jan 12:36 gn 180 29 22 86 37<br /> 27-jan 15:57 gn 237 38 217 46 26<br /> 27-jan 18:19 gn 139 68 124 31 30<br /> 28-jan 13:29 gn 7607 1094 3 93 2<br /> 28-jan 13:34 gn 2642 308 0 94 1<br /> 28-jan 13:56 gn 13646 998 32 96 5<br /> 28-jan 14:58 gn 6138 1211 6801 35 2<br /> 28-jan 18:22 gn 2978 373 3278 39 10<br /> 28-jan 18:36 gn 2696 1781 2138 27 24<br /> 28-jan 19:29 gn 2353 1540 1796 29 21<br /> 29-jan 0:07 gn 342 16 698 -4 34<br /> 29-jan 11:11 gn 678 265 855 17 14<br /> 29-jan 14:48 gn 1792 94 2050 40 13<br /> 31-jan 21:58 gn 363 115 283 45 23 </p> http://www.cwnp.com/bbpress/topic.php?id=6992#post-26508 Wed, 01 Feb 2012 15:05:49 +0000 Kevin Sandlin 26508@http://www.cwnp.com/bbpress/ <p>From lots of past experience of exam candidates comparing their practice test scores to their real VUE exam scores, you should score in the 90s on the practice exam before taking the certification exam at VUE. The questions are very similar, but the pressure of answering questions with no deadline in your sweatpants with a cup of coffee and a CWTS book nearby is much different than the dark little room with other quiet people at the local VUE testing center. </p> http://www.cwnp.com/bbpress/topic.php?id=6992#post-26507 Wed, 01 Feb 2012 14:21:52 +0000 Ironeyes 26507@http://www.cwnp.com/bbpress/ <p>I bought the CWTS exam pack for $50 USD. I did the first exam which was 60 questions and scored 73%. I think i'm pleased with my score. I'm quite new to wireless and networking in general.<br /> I started studying last week. I'm 75% through reading the official Sybex study guide. still got a few chapters to go but i thought i'd risk trying to practice/mock test first to see if it made sense so far.</p> <p>How accurate are these questions in the pack compared to the real exam? i ask because I read somewhere that the questions in the CWTS are not scenario based yet the ones in the pack seem to be as they described mock situations where a company was trying to do something or had some problem. Isn't that scenario based? </p> http://www.cwnp.com/bbpress/topic.php?id=6989#post-26506 Wed, 01 Feb 2012 11:52:25 +0000 Wlanman 26506@http://www.cwnp.com/bbpress/ <p>Jon,</p> <p>I'm not expecting it to be easy, just the opposite. </p> <p>It's just that I had already had more "design" than I had "analysis" experience when I started down the CWAP path. But that book came out before the CWDP book.</p> <p>Again my experience has been at low and specialized level - meaning not WLAN site survey or networking, etc., but design from a manufacturing point of view. </p> <p>I was surprised, actually delighted, that the CWDP book had as much client-side design material inside of it, as it does. There were several sections in it, on things like "guts" level antenna construction that have already helped me at my job.</p> <p>Two great books ! </p> http://www.cwnp.com/bbpress/topic.php?id=6989#post-26505 Tue, 31 Jan 2012 23:01:43 +0000 Wireless Jon 26505@http://www.cwnp.com/bbpress/ <p>CWDP is definitely NOT easy even for a CWAP </p> http://www.cwnp.com/bbpress/topic.php?id=6984#post-26503 Tue, 31 Jan 2012 21:32:13 +0000 Wireless Jon 26503@http://www.cwnp.com/bbpress/ <p>Couple things:<br /> 1. The store genius at the bar I understand have some sort of test software. Good luck getting it.<br /> 2. There are some functions that are are available to a jailbroke phone but it requires a jailbreak. This is a problem for me as my phone is subject to certain regulations. Not sure if jail breaking is negligance.<br /> 3. I was analyzing some traffic today and consistently found iPhones with 1500 associations counted with 1 AP. Why they are associating and disassociating so much I need to explore.<br /> 4. I've seen facetime teaffic setting the from and to ds bits like a WDS or bridge link.</p> <p>***Disclaimer*****<br /> the following does not reflect any sound engineering practices and should only be practice out of deaperation<br /> ***End Disclaimer***<br /> I really wish there were some engineering tools for these things. In the meantime I have a method for these situations. Use a wireless packet analyzer to observe at what RSSI your laptop NIC reports the device under test transmitting and receiving at each data rate. You can get a crude idea of the iPhones RSSI requirements in terms of your laptop's RSSI. This is certainly analogous to performing surgery with a machette. </p> http://www.cwnp.com/bbpress/topic.php?id=6950#post-26501 Tue, 31 Jan 2012 16:29:24 +0000 Kevin Sandlin 26501@http://www.cwnp.com/bbpress/ <p>Again, if it were up to me... ;-)</p> <p>Sybex (www.sybex.com) publishes all the official CWNP study guides. CWNP does not publish study guides, nor do we own the intellectual property within those books. They are all published and owned by Sybex. </p> http://www.cwnp.com/bbpress/topic.php?id=6950#post-26500 Tue, 31 Jan 2012 16:08:01 +0000 Nikko 26500@http://www.cwnp.com/bbpress/ <p>@ Kevin,<br /> Why not offer something like Ciscopress is doing--watermarking the pdf/epub/mobi. And if you have the book already, register the book and offer the ebook version of it for $5--like O'reilly.</p> <p>I have the Kindle version of the CWNA, but I really don't like to read technical books on the kindle. I would rather to have a pdf (formatting is better).<br /> Buying the text book is great if you're going to stay at your home; but if you travel like most wireless engineer, having a lighter backpack is preferred. If getting both (book and ebook) for $70+, is not acceptable. </p> http://www.cwnp.com/bbpress/topic.php?id=6991#post-26499 Tue, 31 Jan 2012 11:32:10 +0000 Wlanman 26499@http://www.cwnp.com/bbpress/ <p>I would bet that many end-users pushed back first, then the Mfg's. There are just too many millions of devices out there to demand they be scrapped. Althought the WFA represents the top 400 or so Wi-Fi manufacturers, there are millions of customers.</p> <p>The WFA was going to be publishing their "Security Roadmap" soon, but I think it's on hold for now. I would bet that this WPA-TKIP issue was one of the reasons.</p> <p>I would bet that they are so busy fixing WPS, and working this into the current crop of certifications, to worry too much about other things. I would bet that their members are none too happy about it. </p> http://www.cwnp.com/bbpress/topic.php?id=6991#post-26498 Tue, 31 Jan 2012 05:35:17 +0000 Jonas Mellander 26498@http://www.cwnp.com/bbpress/ <p>Looking at <a href="https://www.cwnp.com/cwnp_wifi_blog/so-long-insecurity">this blog post</a> it would seem like WPA-TKIP was not supported by recently certified products.<br /> But looking at products released the past year, this does not seem to have been enforced.<br /> Does anyone know what happened? Was there too much pushback from the vendors? </p> http://www.cwnp.com/bbpress/topic.php?id=6986&page=2#post-26497 Tue, 31 Jan 2012 00:34:17 +0000 Wlanman 26497@http://www.cwnp.com/bbpress/ <p>Remember that, unless properly shielded and oriented, that antenna cables become part of the antenna's ground-plane which can affect the (RF) pickup patterns. I see that <u>all</u> the time.</p> <p>In addition, inconsistent cable routing can really make one device behave very much different than another of the same exact model. That's not just RF cables either. The smaller, and more cramped the cable feed area, the stronger the negative influence. </p> http://www.cwnp.com/bbpress/topic.php?id=6986&page=2#post-26495 Mon, 30 Jan 2012 17:36:40 +0000 Frans 26495@http://www.cwnp.com/bbpress/ <p>Would think so. Have 3 laptops, 8xAirpcapNX, 2xProxim, 1xC1060 and PRISM Duette to analyze with. Use them with Wireshark, AM analyzer and Ethereal (prism). AP is about 7 meters away, analyzer adapters either in laptop or with usb cable up to 1 meter away at different positions. I have 1GB material now from the last days. I will analyse this the coming days to see if I didnt make an error myself (probably not).</p> <p>Something weird to think about (doesnt always happen but observed it by accident):<br /> AP on channel 1 20MHz.<br /> Airpcap 1 set at channel 1 20 MHz<br /> Airpcap 2 set at channel 1,-1 40MHz, this one I see a few more frames.<br /> Start 2 different sessions of Wireshark. I used to miss alot of frames in 11g as well the past days, but lately 11n is the last hurdle.<br /> I move with my hand over the laptop cover where the antenna cables are integrated and suddenly more frames pop up (no DRS because it also happens when there is no rate change).<br /> There might be something with polarization and/or synchronization.<br /> 5GHz 11n is in de mean time showing much better results </p>