Dropping N Network after 10.5.2

I too am having these issues
Wireless Card Type: AirPort Extreme (0x14E4, 0x87)
Wireless Card Locale: USA
Wireless Card Firmware Version: Broadcom BCM43xx 1.0 (4.170.46.3)
Current Wireless Network: Cottage By The Sea N
Wireless Channel: 149

As a side bar, Glyn: I am a big fan of your dual Network diagrams. Do you have one for a Dual Network with the router being a Cable modem, not in bridged mode and connecting via DHCP?

Can you post this diagram for me?

Many thanks
Jerry

the update today bumped the firmware for the AirPort Extreme (0x14E4, 0x87) to (4.170.46.5)...

did this fix your problem???

i have the broadcom 4321 802.11n card in my macbook pro core duo march 2006, works great, no drop outs whatsoever....

Yes!

The spontaneous dropping of connection issue seems to be completely resolved by the Airport/Time Machine update.

Update did no good. I am on 10.5.2, Mac Pro Quad Core, Broadcom chip, using N 5Ghz on Airport Extreme (Fast Ethernet version), with latest airport firmware update...

still dropping a few times (maybe 5) a day. Click on airport icon, comes back.

Same here, still drops. I have not had it happen as frequently. It appears that it only happens when I have serious throughput. Otherwise, normal internet browsing and it hangs on just fine.

The last update did not change matters for me either... still happily dropping since 10.5.2.
The irony of all this is that I installed the Broadcom card (from the Mac Pro Airport upgrade kit) into my MBP 17 Core Duo which had an older 802.11g Atheros, because A) I wanted 802.11n, B) I was experiencing dropping issues under 10.4.x. The Broadcom card behaved better in 10.4.x and 10.5 until 10.5., although not really good.
Overall I would say I have experienced the flakiest and most maddening Airport connectivity ever since upgrading from the rock-solid PowerBook G4 to the Intel-based MacBookPro. I even ditched my previously perfectly good D-Link router in favor of an all-Apple solution with the AP Extreme base station in the hope that staying in an "all Apple fold" I would be safer... nope. Shame on Apple AP product managers, who obviously cannot control very well neither their engineers, nor their business partners.

MBP 17 2.16GHz Core Duo, 2GB RAM
Wireless Card Type: AirPort Extreme (0x14E4, 0x87)
Wireless Card Firmware Version: Broadcom BCM43xx 1.0 (4.170.46.5)

No!
I spoke too soon. 802.11n is still dropping.

Just had a drop in the middle of a large file transfer.
In fact, come to think of it, it always seems to be related to heavy activity. Almost as if it dropped after every 3gigabytes. (or something)

I'm getting angry about this now.

Well, I installed the update yesterday at about 1630, and according to Console, the interface came up at startup and stayed up. As at this posting, the interface has been up for 17 and a half hours without dropping - which is way in excess of what I had before.

Cautious optimism here.

Wireless Card Type: AirPort Extreme (0x14E4, 0x87)
Wireless Card Locale: Worldwide
Wireless Card Firmware Version: Broadcom BCM43xx 1.0 (4.170.46.5)

Message was edited by: Peter Whysall - Inserted hardware details from System Profiler

Message was edited by: Peter Whysall

I have just tried a bunch of experiments to see if I can fix this.

I find that I can cause the Airport connection to fail by copying a large (8GB) file from a USB Airdisk - to my desktop. Mid-transfer the menu Airport icon goes from all-black to grey.

The connection typically drops within the first 1-2 gigabytes. The file transfer happens at a reasonable 5MB/s - so I get a disconnection after about 5-10mins. This is repeatable enough to try different things and see if the problem has resolved.

1) Tried booting in safe-mode. Which apparently corrects some Airport issues.
No Luck

2) VMWare Fusion was a suspect. So I uninstalled it and tried again.
No Luck

3) Lots of Wifi issues recommend deleting preferences and keychain prefs and starting from scratch.
No Luck - still seeing drop outs.

I'll try more stuff and report back.

Couple more tests.

Option-clicking channel in Airport Utility allows you to pick a fixed channel for 802.11n. Replacing Automatic.
No Luck

Pulled Power cable from Mac Pro for 10seconds to reset PMU.
No Luck

Extra thorough nuking of preferences. All keychain references. All prefered network and the Library/Preferences/System Settings/com.apple.airport.prefs.
No Luck

😟

Tests to date....
Safe Mode boot
VMWare Uninstall
Delete Prefs and Keychain
Manual Channel Selection
Power Cycle Mac Pro and Base Station
Removing 802.11X options
Creating new network Location
Using Manual DNS
Reset PRAM
Turning IPv6 off

The only thing that stops the network dropping is switching to 802.11g.
Does anyone have an 10.5.2 Running 802.11n @ 5GHz reliably?

Actually having luck so far with using N on 5Ghz but with Wide channels OFF (the only thing I've changed). Otherwise like you, the only thing I can do to fix is go back to G.

So with wide channels off, you are seeing a stable, non-dropping connection?

So far flawless with no wide channels. Will know more tomorrow when I hit the daily routine of having multiple java (financial apps) running while going through normal uploading/downloading (seeing quite a few drops each day in that usage).

Tried a hefty upload tonight to test, one which had gone gray three times on a try last week before shutting off wide channels and it finished without a hitch. Will try again tomorrow with said apps running.

Thing is... I still can't get past the fact that we all seem to have the same Broadcom chipset, or is that just the overwhelming usage of those cards making for the comparison I wonder...