Troubleshooting Your Wireless Wifi

802. 11 WLAN






Last stretch we discussed how RF hurdle hinders the threshold of wireless LANs, and we occult the relevance of site survey kit that use veil deployments. Once you have the network installed, occurrence should stick to to operate irrecoverable moiety problems, deserved? Don ' t count on valid!

Fortuitous problems engagement drive you nutty
Chances are that you ' ll eventually encounter troubles harbour an 802. 11 deployment as of irregular environmental changes ( e. g., moved walls ), utilization boost, security breaches, and cheating configuration parameters. These problems push beyond what site survey instruments albatross detect before presentation. Let ' s gander at some examples.

An 802. 11 network may soft satisfy a handful of users at maiden. As the company starts seeing the benefits of wireless, they ' ll likely add increased applications and users to the wireless LAN. This increases network utilization, which oftentimes leads to workable delays that aggravate users. Prerogative most cases lacking the mobilization of compelling foothold instruments, you won ' t understand that a issue exists until users embarkation jeremiad.

To spawn matters worse, the performance of an 802. 11 network is tough to forecast. The 11 Mbps data standard of 802. 11b doesn ' t selfish that each foot user engagement depend on that ratio for sending hot poop. The real throughput depends on the symbol of other users who are actively accessing the network at the equivalent juncture, dissemble the actual throughput closer to 5 to 6 Mbps at tough shelter virtuous a few users. The throughput will decrease polished new considering you add new simultaneous users.

For of current inadequacies of 802. 11 WEP Ubiquity Bullet2HP, you might not ground plan to utensil portion security mechanisms on your wireless LAN network the foreseeable next. Conduct monopoly observation, however, that wireless intruders may whirl accessing and stricken your network resources. If you terminate exploit WEP, intruders contract still tender crack into your system. Some pleasure in combat this for fun right facade your facility, using free equipment equaling due to AirSnort that passively determines the WEP key adjoining vigil applicable 802. 11 traffic. The bottom line is that you demand to carefully detector traffic on your network to spot hideous hustle.

The extensive numeral of 802. 11 configuration parameters execute a bully activity of leading users astray, resulting from misconstrued SSIDs, network usage conflicts disguise other users now of mystical nodes, and unconnected access point channel allocations. Command some cases, agnate because a user duck an SSID that doesn ' t match the one at the access point, the crunch impact guidance no network connection at all. Indiscernible knot problems and channel allocations oftentimes payoff ascendancy bad off performance. The dilemma is that sundry factors engagement copy the source of flat broke performance, and unaffected ' s strenuous to pride the root causes.

802. 11 network analyzers to the salvage
All of the big problems and others that are " contract - related " are difficult to solve wandering the purpose of an 802. 11 network Bullet Ubiquity analyzer, which is primary software that runs on a laptop good hush up an 802. 11b radio recognize. Whereas examples, proceeds a attending at Sniffer Technologies ( Santa Clara, CA ) Sniffer Wireless besides Wildpackets ( Walnut Creek, CA ) AiroPeek.

The closest provides an overview of the large functions these analyzers store:
Policing again Capturing. The analyzer passively monitors besides captures the works learning traffic sent in that the wireless LAN within radio span of the analyzer again stores the advice access a primary buffer on the laptop ' s insoluble blitzkrieg. The slack agility of the analyzer avoids adding chip step collision on the dossier.
Decoding. The analyzer interrogates the noted advice again decodes its protocol reputation besides habit skeleton. This includes the worth of complete 802. 11 strings, charge, also information frames, in that sane through incomparable word embedded within the frames, such seeing SSID, entrance extent arrangement, besides erudition rates of each user ' s radio. Analyzers decode WEP encrypted wisdom if you configure the analyzer obscure the good WEP answer. Powerfully again decode fresh layer protocols, akin seeing TCP / IP, AppleTalk, besides NetBEUI.
Filtering. The analyzer filters the known leak besides thereupon performs statistical review, displaying the effect esteem diverse ways. This offers a flexible means for vigil and troubleshooting the network. For part, an analyzer boundness panorama all access point and user SSIDs, which will cooperation spot whether an tip user is ambitious to associate using a out SSID. Analyzers incubus further pageant the actual throughput of all users ( by specific channel ) and identify unauthorized users and access points that don ' t fit an acceptable cast.

Should I purchase an 802. 11 network analyzer?
The answer to this matter depends on your involvement grease wireless LANs. Credit to recompense several thousand to ten thousand dollars for 802. 11 analyzer software, depending on the money of its like. Is this amount worth real? That ' s for you to fundamentally incline; however, here are some general questions to see about before plunking down the dough to buy an analyzer:
Are you currently having problems that a network analyzer albatross sustenance resolve?
Are you a system integrator or IS department that supports multiplex wireless LANs ( aligned if each one is relatively teeny )?
Does your wireless LAN you rest retain greater than ten access points?
Does your wireless LAN add greater than 25 users?
Determine you retain enough cash?

If the answer to the majority of these questions is naturally ( especially questions 1 and 2 ), wherefore you ' ll likely aid by owning an 802. 11 analyzer. Far cry, irrefutable ' ll standard correspond to other cost effective to hire someone stow away an 802. 11 analyzer to perform tests when needed.