<div dir="ltr">Very interesting. <div>Thanks to share and thanks to Terry for this detailed report.</div><div><br></div><div> Lionel.</div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">
2014-02-07 16:10 GMT+01:00 Adam Holt <span dir="ltr"><<a href="mailto:holt@laptop.org" target="_blank">holt@laptop.org</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><i>[Terry Gillett summarizes his weeks of testing, </i><i><i>with this very revealing report below</i>. That's <a href="mailto:tgillett@gmail.com" target="_blank">tgillett@gmail.com</a> of the Village Telco project: can we/Nepal/Lesotho/others help him add the key takeaways to <a href="http://wiki.laptop.org/go/Wifi_Connectivity" target="_blank">http://wiki.laptop.org/go/Wifi_Connectivity</a> so the "almost 2 million XO-1s worldwide" can benefit? Spoiler Alert: XO-1 deployments must carefully buy the correct Wifi Access Point, EG "Linksys WRT54GL" or "Billion 7404VGP" appear to solve most all problems. Likewise we've had a lot of success in Haiti with the TP-Link TL-MR3020.]</i><br>
<div><br><br><div class="gmail_quote">SUMMARY<br><br>The core problem is that XO-1 laptops will not reliably connect to a range of wifi Access Points (AP). By comparison, XO-1.5 and later laptops will successfully connect to the same APs.<div dir="ltr">
<div><br></div><div>The behaviour of a group of XO-1s is different from that when they are tested individually. A single XO-1 may connect quite reliably, but when used in a group of ten or more, many individual XO-1s will fail to connect to the AP.</div>
<div><br></div><div>Note that this issue is just about connecting to the AP, it is not about whether the AP can sustain a large number of connections or handle the associated data throughput requirements.</div><div><br></div>
<div>A number of routers configured as APs have been tested to establish a baseline.</div><div><br></div><div>The test process used requires 10 XO-1 laptops and is as follows:</div><div><br></div><div>1. Set up the AP on an unoccupied wifi channel, at least two and preferably three channels away from unoccupied channels.</div>
<div>2. Connect each XO-1 individually to the AP and check that it is operating correctly and has adequate signal strength.</div><div>3. Power off all the XOs</div><div>4. Start up one XO and allow it to connect successfully.</div>
<div>5. Start up the other none XOs</div><div>6. When the last XO has completed its boot up sequence, check the connection status of each XO.</div><div><br></div><div>The result of a connection test for each XO is one of the following:</div>
<div>1. Successful automatic connection</div><div>2. No connection, but AP icon shows in Network Neighbourhood (NN) window</div><div>3. The AP icon does not appear.</div><div><br></div><div>Typically there will be a mix of XOs in each of the three states. </div>
<div>A Pass requires that all ten XO-1s are successfully connected at the end of the test without manual intervention.</div><div><br></div><div>The proportion of XOs in each state will typically vary from 20 to 80% in a Failed test.</div>
<div>The proportion of successful connections seems to vary by router type, but changes in repeated tests.</div><div>Individual XOs will typically be in different states in repeated tests.</div><div><br></div><div>A range of routers has been tested with this procedure and the results appear in the table below.</div>
<div><br></div><div>The only two routers that passed the test were the Billion and the Linksys.</div><div>Interestingly both these routers date from the same vintage as the XO-1.</div><div><br></div><div>Note that testing with less than five XO-1s results in a much greater likelihood of a Pass result, and if the same AP is tested with ten XO-1s it will likely fail. </div>
<div><br></div><div>A Pass result with ten XO-1s is considered (at this point) to be a reasonable indication of likely success in a real world deployment with greater numbers of XOs.</div><div><br></div><div>The working hypothesis is that modern APs have implemented the wifi specs and/or default configurations in a way that has resulted in an interoperability problem with the wifi implementation in the XO-1.</div>
<div><br></div><div><br></div><div>ROUTER TEST RESULTS<br></div><div><br></div><div>Billion 7404VGP (old, Star Int, proprietary OS) Pass</div><div>Linksys WRT54GL (old, Broadcom, DD-WRT) Pass</div>
<div><br></div><div>Netgear FWG114P (old, proprietary OS) Fail</div><div>TP Link WR710n (new, proprietary OS) Fail</div><div><br></div><div>TP Link WR703 (Atheros AR9331, OpenWrt) Fail</div>
<div><br></div><div>TP Link WR842 (Atheros AR9287, OpenWrt) Fail</div><div>TP Link MR3020 (Atheros AR9330, OpenWrt) Fail</div><div>TP Link WDR4300 (Atheros AR9341, OpenWrt) Fail</div>
<div>VT MP01 (Atheros AR23xx, OpenWrt) Fail </div><div>VT MP02 (Atheros AR9331, OpenWrt) Fail<br clear="all"><br>--<br><div dir="ltr">Unsung Heroes of OLPC, interviewed live @ <a href="http://unleashkids.org" target="_blank">http://unleashkids.org</a> !</div>
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