Network Analyzer

Until afresh there accept been two primary techniques active to troubleshoot Wi-Fi 802.11 wireless networks — arrangement assay and RF spectrum analysis. Arrangement assay is aswell frequently referred to as arrangement website assay or Wi-Fi scanning. Lately, two new WiFi analytic accoutrement accept been alien that augment the ambit of troubleshooting techniques — ‘Wi-Fi Approach Analysis’ and ‘Connection Analysis’. This commodity briefly describes 4 strategies for troubleshooting Wi-Fi networks, and mentions some of the ‘pros’ and ‘cons’ associated with anniversary strategy.

Expensive RF assay accoutrement are accessible to admeasurement a array of ambit that alone an RF architect has a clue what they beggarly and the implications of their values. But if it comes to networks — active or wireless — ultimately, what one should be a lot of absorbed in is throughput performance. 802.11 (i.e. Wi-Fi) is a able-bodied accepted that includes a array of protocols that advice it acquaint wirelessly with added devices. Unless one has affectionate ability of the 802.11 accepted and its abutting workings, afresh it is not accessible to adumbrate how an 802.11 arrangement will behave if you are armed alone with RF measurements. This is why it is important to focus on achievement metrics — back these added accurately adumbrate how a wireless arrangement will in actuality behave in a real-world environment.

What follows is a abrupt accession to 4 troubleshooting techniques (network discovery, RF spectrum analysis, WiFi approach analysis, and WiFi affiliation analysis). We activate with a arbitrary of the pros and cons of the altered troubleshooting techniques, which should accord you a high-level appearance of the administration in which the acreage of WiFi affection is currently headed:

Summary:

1. Arrangement Discovery:

Advantages:

Inexpensive

Disadvantages:

Of bound use back it alone detects alarm packets transmitted by 802.11 admission points. It does not “see” or admeasurement RF activity transmitted by non-802.11 accessories (which boss the RF environment) or, even, actively transmitting 802.11 stations.

2. RF Spectrum Analysis:

Advantages:

Detects all RF transmissions aural a abundance band.

Based on the manual arrangement you ability be able to analyze the antecedent of the interference.

Disadvantages:

Expensive — back it requires proprietary hardware.

When it detects RF arrest in the 2.4x or 5.x GHz ISM bands, it can not adumbrate how this will affect 802.11 accessories or WiFi arrangement achievement — back it knows annihilation about the 802.11 accepted nor how its basal protocols plan to abate abeyant sources of interference.

3. WiFi Approach Analysis:

Advantages:

Inexpensive — uses off-the-shelf 802.11 devices.

Measures RF arrest through the eyes of an 802.11 accessory — hence, can bigger adumbrate how an 802.11 Wi-Fi arrangement will in actuality accomplish in the accepted environment.

Can quantify the accepted achievement for anniversary Wi-Fi channel, thereby acceptance you to accept the optimal channel.

Disadvantages:

Of bound use if attempting to analyze the antecedent of interference.

4. Affiliation Analysis:

Advantages:

Inexpensive — uses off-the-shelf 802.11 accessories or your congenital 802.11 adapters.

Measures throughput achievement of your 802.11 accessories if affiliated to a Wi-Fi arrangement — which is the ultimate metric if it comes to troubleshooting a network.

Disadvantages:

Of bound use if attempting to analyze the antecedent of interference.

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Descriptions:

1. Arrangement Discovery

An 802.11 arrangement assay apparatus will address the Service Set Identifier (SSID) for anniversary admission point (AP) it detects, forth with the approach acclimated by the AP. About every 100 mSec an AP transmits a baby alarm packet and a assay apparatus (running on your laptop and application its 802.11 wireless adapter) detects the alarm and adds the packet advice (including the AP’s SSID) to its account of accepted admission points. In addition, the assay account may address arresting backbone (in dBm units) of the alarm as detected by the applicant adapter. The beacon’s arresting backbone is a absorption of how abutting the AP is to your accepted location. Though this is advantageous information, it does not acquaint you annihilation about non-802.11 accessories or even how active the admission credibility are. That is, your laptop could be sitting next to a bake oven and the assay apparatus would be clueless as to its existence. The assay apparatus alone knows about alarm packets transmitted by 802.11 accessories and can not see non-802.11 transmissions.

Network assay accoutrement use the 802.11 adapter congenital into your laptop or an alien USB 802.11 adapter. Back they do not crave added proprietary hardware, afresh they are almost bargain (even free).

AP Alarm Backbone Is Not A Admeasurement Of Performance

The arresting backbone appear by a arrangement assay apparatus is the arresting backbone of a alarm as abstinent by the 802.11 wireless adapter installed on your laptop or desktop machine. Anniversary admission point (AP) sends out a abbreviate beating or alarm of advice about every 100 mSec. It’s agnate to an ‘I’m over here!’ shout. It does not apprehend a acknowledgment from the 802.11 applicant adapters that may apprehend it — it’s just a one-way shout. The arresting backbone that the arrangement assay apparatus letters is the arresting backbone of a beacon, and the arresting backbone of a alarm is a absorption of how abutting that AP is amid to you. It is not a absorption of the achievement or throughput you can apprehend by advertence with that AP — rather, it is an adumbration of the AP’s concrete area about to you. If the AP with the arch alarm has 24 applicant adapters associated with it that are actively transmitting and accepting information, and if you affix with that AP afresh you will be applicant amount 25 and your arrangement affiliation will assume slow. On the added hand, if you instead accept to accessory with an AP whose alarm backbone is weaker but which is not associated with added applicant adapters, afresh you will acceptable acquaintance bigger performance. Furthermore, the AP with the arch alarm arresting may be application a approach that is accountable to RF arrest — again, aspersing its performance. If it comes to networking (both active and wireless) what we affliction a lot of about is performance. And the key to achievement is ‘throughput’ (i.e. bytes-per-second). Though a beacon’s arresting backbone can affect it’s performance, what’s added important is the amount of applicant stations that are aggressive for the aforementioned AP and whether the approach currently acclimated by the AP is accountable to RF arrest from added wireless accessories in the vicinity.

2. RF Spectrum Analysis

An RF spectrum analyzer is the apparatus of best for audition and anecdotic sources of RF interference. Spectrum analyzers are a basal apparatus acclimated for celebratory radio abundance (RF) signals. Back they ascertain all RF transmissions (both 802.11 and non-802.11) afresh they accommodate a abundant bigger account of the RF environment, which afresh helps you analyze and, perhaps, locate accessories that could be interfering with your Wi-Fi network. Typically an RF spectrum analyzer will apply a 2-dimensional affectation area the vertical arbor (Y-axis) represents the backbone of a arresting and the accumbent arbor (X-axis) represents the abundance of a signal. If the ashen trace of the interfering RF transmissions accept ahead been documented, afresh it ability be accessible to actuate which blazon of accessory is causing the disturbance. As for tracking-down and attempting to locate an interferer, in convenance this is added difficult than it ability assume on the surface. Not alone does it crave the use of a directional antenna, but in an calm ambiance with after-effects bouncing all over the abode (off of altar and walls) afresh how do you anticipate from which administration the beachcomber originated. In added words, if your directional antenna measures a arresting from a beachcomber you don’t apperceive whether that’s the aboriginal beachcomber or the aftereffect of a beachcomber that has bounced off of an article or bank in the room.

3. WiFi Approach Analysis

Today, one of the hottest capacity discussed by Wi-Fi basement manufacturers is “using the basement to troubleshoot the infrastructure”. That is — application 802.11 accessories to troubleshoot an 802.11 network. Approach assay is a new address we accept championed and pioneered. This blazon of apparatus uses 802.11 accouterments to accomplish abstracts accretion — hence, the after-effects absolutely reflect how RF arrest in the bounded ambiance affects throughput achievement of 802.11 channels. This is not accessible application an RF spectrum analyzer. By advantage of the actuality an 802.11 approach analyzer angle the RF apple through the eyes of an 802.11 device, afresh the analytic advice it provides added carefully mirrors the achievement you can apprehend from your own 802.11 applicant adapters. This makes it easier to troubleshoot and fix problems and allows you to accomplish better-informed decisions apropos how best to configure your wireless arrangement for optimal throughput performance.

4. Affiliation Analysis

Ultimately, the basal band for any arrangement (wired or wireless) comes down to throughput achievement — that is, how abounding bytes-per-sec can be transferred from one bulge on the arrangement to another. The dBm and RSSI ethics that are generally referred to in the ambience of wireless networks don’t beggarly abundant if you can’t somehow chronicle them to a achievement metric. Before we can absolutely activate to troubleshoot a wireless arrangement we charge a way to criterion its performance, so as modifications are fabricated we can actuate whether or not they absolutely accomplish a aberration in the network’s performance. A affiliation assay apparatus allows you to anon analyze the achievement and believability of altered combinations of 802.11 adapters and admission points.