Posts

My Apple & Raspberry Pi(e)

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Apologies for the appalling title of this blog post, but hey, you're here! :) In this post I talk about my purchase of a Raspberry Pi (by devious means) and how I set it up as an iPerf server. I have recently been reading lots about the Raspberry Pi mini/micro/teeny-weeny ( I don't know what the correct term is...) single board computer, which has been created by the Raspberry Pi Foundation in a attempt to promote the teaching of basic computer science in schools (according to Wikipedia ). I've been itching to get my hands on one for a while and finally came up with a great excuse to buy one and have a play with it. They're incredibly cheap (around £30 for the basic computer board), so I concocted a flimsy excuse about buying one to teach my son about computing. After letting him play with it (and get bored) for about 30 minutes, I quickly slipped in to my home lab where I will no doubt continue to 'evaluate' it. The Pi is supplied with a flavour of Debia

Adjacent Channel Interference

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I was inspired to try a bit of experimentation following Keith Parsons' recent WiFi stress testing sessions, where he conducted testing on a number of vendor APs to observe at what point they collapsed in to a heap  due to traffic throughput. I can't carry out anything as grand or detailed as Keith (I don't have his knowledege, brains or resources!), but I thought it might be fun to test some de-facto rules around the use of the 2.4GHz band for WiFi. In summary, due to the bandwidth requirements of WiFi equipment, it recommended that the spacing of at least 22MHz is allowed between the channels being used in the 2.4GHz band. This is required for the bandwidth requirements of the older DSSS modulation scheme. The newer OFDM modulation technique requires only 20MHz of space, but for reasons of backward compatibility, the 22MHz rule persists. The band itself is sliced up in to 11, 13 or 14 channels depending where you are in the world. Each channel is 5MHz in width, as

Aerohive AP121 Alternative Power Supply

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Got yourself a free Aerohive 121 AP after a recent training course or webinar? Got it home and found it's got no PSU!? Yeah, annoying isn't it... Get yourself one of these 'bad boys' off Amazon - bought one this week and works a treat! http://www.amazon.co.uk/dp/B004V2IZG4/ref=pe_217191_31005151_3p_dp_1 Disclaimer : if it blows your AP up don't blame me...mine certainly worked OK :) *** Update 11th October 2013*** Works well for an AirTight C-55 AP too!