Inter-operability of Draft-n equipment

Finalisation of 802.11n is still reportedly over a year away. There is of course no guarantee (actually, little likelihood) that any of the draft-n gear available now will be upgradable to the standard, when it comes.

The conventional wisdom for using draft-n equipment at the moment is to get all the pieces from the same manufacturer, to make sure they work together as intended. But that's not always possible.

Have any of the computer or networking magazines, or any of the consumer-protection testing labs, run any studies comparing how well (or how poorly) 'mixed' environment networks run? Things like 'The A pcmcia card works with B's router but not C's access point, while D's pci adapter works with routers from A and C but not B', etc., etc.

Given that there are only, what?, four or five or six major manufacturers of consumer- and SOHO-level equipment, it shouldn't be too hard to put the more popular models through their paces.

cheers,

Henry

Reply to
Henry
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On Sat, 9 Feb 2008 16:07:24 +0200, snipped-for-privacy@eircom.net (Henry) wrote in :

Why not?

My own conventional wisdom is to stick to 802.11g gear. Why pay a premium for uncertain value? When more signal is needed, better antenna(s) are often a better bet.

I've seen some small tests, but don't know anyone that's undertaken the gargantuan task of wide interoperability testing.

Actually very hard to get all the gear and test it properly, and hard to see how it would pay off.

Reply to
John Navas

I gather you have no faith in the "Wi-Fi Alliance".

Reply to
LR

On Sat, 09 Feb 2008 16:20:46 +0000, LR wrote in :

The point is that n can't be certified until it's approved.

Reply to
John Navas

While that is stating the obvious, apart from the OP's first sentence the post was about draft n. "Inter-operability of Draft-n equipment"

Reply to
LR

snipped-for-privacy@eircom.net (Henry) hath wroth:

Actually, the slipping schedule seems to be a continuously moving target that always seems to remain a year or two away. The current guess is Dec 2009 for the grand finale, and about July 2009 (my guess) for something that can be updated to whatever is approved.

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Well, Dec 2009 is a bit less than 2 years away. Anything you buy today will probably be obsolete by then. It's not just the MIMO part that will change in the next two years. Router and wireless features will also improve. For example, dual SSID's for "guest" WLAN's. Built in intrusion detection.

Nope. All the same chipsets from the same manufacturer. There's no guarantee that even a single manufacturers stuff will talk to other products made with another vendors chips.

Incidentally, the spec includes provisions for two radically different forms of MIMO. Spacial multiplexing and beam forming are totally incompatible.

Sorta. This one is several years old:

and doesn't really do any interoperability testing. Some of the reviews on this site test performance with compatible MIMO and ordinary wireless clients. I haven't seen any Interop style bake off testing yet.

Yep. However, new MIMO models come and go at an alarming rate. Product lifetimes seem to be about 6 months. By the time the tests are organized, run, reported, and published, all the products tested will be obsolete. However, that's not why nobody is doing such tests. It's because many of the claims presented by MIMO proponents are unsupportable and all too easily proven to be baloney. Nobody wants to sponsor a comparative test that demonstrates that MIMO is about speed, not range.

Reply to
Jeff Liebermann

The Wi-Fi Alliance, as usual, keep their interoperability test procedures for Draft N under wrap. As an aside I did find this web site which does have a pdf. of how they did it for 11a,11b and 11g.

Reply to
LR

LR hath wroth:

Well yes. The test procedures are their primary asset. If anyone can obtain the procedures and perform their tests, then someone might discount their rather high cost of certification (About $25K). Of course, that won't stop someone from trying:

There are other vendors, but as usual, I can't find them in my bookmark mess.

Meanwhile, I'm still dealing with WEP ASCII/BINARY conversion incompatibilities and regularly find wireless clients that can't seem to get a DHCP assigned IP from certified wireless routers. There are a few other big holes in Wi-Fi certification.

So, when all the products are certified and largely indistinguishable, vendors are competing on the basis of buzzwords and unsubstantiated claims. That attract class action suits:

Everybody lies, but that's ok because nobody listens.

Never mind interoperability. Just getting MIMO to work in the first place is somewhat of a challenge:

Most of the vendors are assuming that MIMO will go the way of DOCSIS certification, where there is no interoperability testing between the DSLAM and the DOCSIS modem. Instead, there are certification tests, performed with a standardized (CableLabs) test suite, on each device. In theory, if they communicate reliably with the test equipment, they should talk reliability to each other. In general, that has worked well.

Reply to
Jeff Liebermann

On Sat, 09 Feb 2008 17:10:37 +0000, LR wrote in :

Sorry, but I can't parse that.

Reply to
John Navas

Why not? Erm ... what about the situation where a single manufacturer just doesn't make all of the parts that you need?

Here's one scenario, but of course there will be others. Apple's latest Airport Extreme Base Station is draft-n, as are all of their current computers. But they don't have an internal upgrade card for older Macs that came with built-in 'b' or 'g', nor do they sell any usb, pci, pcmcia or expresscard add-ons. Older machines in the building have to connect on 'g', which can slow down the whole network. Unless, of course, _someone else's_ usb, pci, pcmcia or expresscard draft-n add-ons will inter-operate functionally with Apple's gear. Get my point?

cheers,

Henry

Reply to
Henry

| There are other vendors, but as usual, I can't find them in my | bookmark mess. | | Meanwhile, I'm still dealing with WEP ASCII/BINARY conversion | incompatibilities and regularly find wireless clients that can't seem | to get a DHCP assigned IP from certified wireless routers. There are | a few other big holes in Wi-Fi certification. | | So, when all the products are certified and largely indistinguishable, | vendors are competing on the basis of buzzwords and unsubstantiated | claims. That attract class action suits: | | | | Everybody lies, but that's ok because nobody listens. | | >As an aside I did find this web site which does have a pdf. of how they | >did it for 11a,11b and 11g. | >

| | Never mind interoperability. Just getting MIMO to work in the first | place is somewhat of a challenge: |

| | Most of the vendors are assuming that MIMO will go the way of DOCSIS | certification, where there is no interoperability testing between the | DSLAM and the DOCSIS modem. Instead, there are certification tests, | performed with a standardized (CableLabs) test suite, on each device. | In theory, if they communicate reliably with the test equipment, they | should talk reliability to each other. In general, that has worked | well.

I have a native distrust of industry sponcered certification and interoperability testing. My most recent experience was with the CTIA certification of cell phone handsets. The process was quickly watered down and the testing fees become a profit center for the parent organization.

Reply to
NotMe

On Sun, 10 Feb 2008 12:43:01 +0200, snipped-for-privacy@eircom.net (Henry) wrote in :

Why not pick a manufacturer that makes all the parts you need?

Reply to
John Navas

I guess the OP's point is that there isn't one. Read what he wrote again.

Reply to
Mark McIntyre

On Sun, 10 Feb 2008 23:16:57 +0000, Mark McIntyre wrote in :

  • Apple is just one manufacturer
  • Any device can be attached with a wireless Ethernet client bridge.
  • OP problem is easily addressed with Linksys WGA600N Wireless-N Game Adapter and a number of Linksys Wireless-N wireless routers
Reply to
John Navas

Correct but irrelevant to his actual statement which was

"what about the situation where a single manufacturer just doesn't make all of the parts that you need?"

Note that he did not make this statement specifically with reference to wireless, apple or pre-n.

Reply to
Mark McIntyre

On Mon, 11 Feb 2008 23:27:25 +0000, Mark McIntyre wrote in :

No such actual situation has been demonstrated.

Reply to
John Navas

He didn't say it had - it was an answer to the question "why not?" in relation to the remark that it isn't always possible to pick a single manufacturer.

Reply to
Mark McIntyre

On Tue, 12 Feb 2008 22:13:59 +0000, Mark McIntyre wrote in :

Again, no such actual situation has been demonstrated.

Reply to
John Navas

Again, HE DIDNT SAY IT HAD. What is it with you ? Do you enjoy being a total dipstick?

He was pointing out that if you can't get it all from one maker, you can't get it all from one maker. Whats to disagree with?

Reply to
Mark McIntyre

On Wed, 13 Feb 2008 23:38:50 +0000, Mark McIntyre wrote in :

Same question to you. He posed a meaningless question.

That you can't, because you can, as I demonstrated.

Regardless, that discourtesy was totally uncalled for, and I'm now done with wasting time on this silly issue. Feel free to have the last word.

Reply to
John Navas

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