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Our current setup in our office uses a single router with 13 computers connected through wired interfaces. We are out of free ports and we need to support an additional 30-50 computers.

We need to guarantee at least 99.9% network connectivity uptime for these computers. All of these computers also have WLAN cards in them.

I am hoping to avoid having to run the additional cabling needed to support these new computers. Is wireless networking a potential solution?

Is this kind of reliability and uptime achievable with wireless APs?

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99% is 3.65 days a year outage. That's 7.20 hours a week, or 1.68 hours a day. If my wireless was down for 1.68 hours a day, I'd be majorly annoyed. –  tombull89 Feb 13 '13 at 13:14
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99.9% is 8.76 hours a year, 42 minutes a week, and 10 minutes a day. That's better, but you're going to need a dedicated wireless setup - Aruba, or Meru - you're not going to be able to do this with daisy-chained SOHO routers. Not without wanting to have horrible throughput, anywya. –  tombull89 Feb 13 '13 at 13:17
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@Tombull I think your math might be wrong. It's more like 15 minutes per day for 99% (which is still bad) –  MDMarra Feb 13 '13 at 13:19
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A guarantee is something that you put in writing and has a monetary value attached to it. If you have not done that or most likely will not, the guarantee (and the question) is not significant. –  Greg Askew Feb 13 '13 at 14:12
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@randomguy - I've edited this to remove the cost/subjective parts of this question. Asking about dollars is subjective and doesn't really fit how this site works. Hopefully, I've rephrased enough to keep this question open while keeping the original intent of your question there. –  MDMarra Feb 13 '13 at 17:51

5 Answers 5

100% uptime isn't something anyone can guarantee for any service. Don't make this promise. It seem you've edited your question and changed it to 99.9%. This is around 8.5 hours of downtime per year. This is much more do-able, but I would still be leery of wireless for other reasons

That being said, wireless networks are much more prone to interruption than wired connection. The per-device throughput is far lower, as well. Are you familiar with profiling RF interference? If you're going to deploy wifi as the only means of connectivity in an office, then you should be.

If you're looking to support 50 clients over wireless, if suggest you look at getting at least two 1140 series Cisco APs. These list around $800 a piece. A $40 linksys isn't going to cut it here. At that kind of money, you can grab a 24 or maybe even a 48 port SMB switch to wire in these additional computers.

I've deployed a somewhat large (400+ AP) wireless network at a mid-size university and nowhere was it the only way to connect, except outdoor areas an public areas like lobbies. All classrooms and dorm rooms had wired connections as well.

The bottom line is that it can be done, but it won't be as reliable as a wired connection and if you want it to be reliable at all, it is going to cost $ and needs to be planned by someone that understands RF interference and other 802.11 specific challenges. It's not like plugging a router in under your desk at home and calling it a day.

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What he said about decent APs. –  Tom O'Connor Feb 13 '13 at 13:27

No, you can not. Point, game over.

Even if it works, WLAN is open to outside interruptions that may be hard to fix. Some broken Microwarve may take down the network. Anything that needs a quarantee - should not be wireless. No way to do it.

Plus the bandwidth will suck - but whethr this gets into the problem area depends on what you DO . but even then, 50 people will likely need more than 1 channel. And more than one AP for coverage.

I Would strongly say no.

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If your uptime guarantee contains no lines about minimum speeds, WLAN could work, but first and foremost, you'll have much less throughput than you would with a proper switch and physical cables. A good quality WLAN can be quite stable, but the bandwidth is shared (even in MIMO) and you will probably have issues with latency if more than a few servers decide to make use of the connectivity simultaneously. 802.11a is more stable, and resistant to interference, but I'd personally skip the headaches, and pay out for proper stuctured cabling, and a good switch or two.

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Short answer, No.

Wireless is very easy to overload and saturate to the point of being useless. In addition wireless is a shared resource where only one computer can transmit at a time. The more computers you add the lower the maximum theoretical bandwidth becomes. It is very similar to Non-Switched Ethernet where the theoretical limit was about 60% of the physical bandwidth when it was fully congested. Yes you can add more access points, but you are still left with another fundamental problem with wireless, interference. If someone decides to bring in their MIFI card and fire it up, it may cause interference with your wireless network and may cause one or more systems to have a marginal signal.

Overall a wired network will give you the reliability you are looking for, and you can still set up a wireless network, but with a more reasonable SLA.

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It is possible to implement a reliable wireless network. But it's a difficult and expensive task... not something in the price range a company with "a single router with 13 computers connected via the Ethernet" could afford.

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