"About Time Capsule and AirPort Base Station (802.11n) Firmware 7.3.1
The Time Capsule, AirPort Extreme and AirPort Express Base Station with 802.11n* Firmware 7.3.1 updates include bug fixes. AirPort Extreme Base Station with 802.11n* Firmware 7.3.1 also includes security fixes.

This update requires AirPort Utility 5.3.1 or later. AirPort Utility 5.3.1 or later can be obtained via an automatic software update or as a manual download...

BTW: Ken Lo wrote with a note for those that still can't get TM to recognize their Airdisks to check the AirDisk setup/config - saying that Secure Shared Disks With a disk password are recognized, but not Secure Shared Disks With accounts.

Apple also has a doc About the security content of AirPort Extreme Base Station Firmware 7.3.1.
A "Time Machine and Airport 1.0 Update" was also released on 3/19/2008:

"About Time Machine and AirPort Updates v1.0
This update is recommended for all users and includes compatibility improvements for using Time Machine with Time Capsule, as well as AirPort driver fixes.
Requirements: OS X 10.5.2 Client Only"

Reader Feedback: (later reports first)
I welcome other reader feedback on this firmware update. (Include info on network, macs, etc.)

(added 3/26/2008)
"I too am experiencing a problem where Airport Extreme is no longer respecting the "enable default host" setting under the NAT tab. To allow outside connections to get through, I must now set up individual ports through the "Port Mapping" tab under "Advanced". Is anyone else having this issue besides Cedar?
cheers, Amin"

I'm running Bridge mode but if anyone else sees this also let me know. (Since this is the 2nd note on this I suspect it's common.)

Tip for Initial TM Backups to USB Connected Hard Drives: (updated w/tip and reply)

(added 3/26/2008 - see below for reply to tip)
"After the recent updates, my AEBS, 500GB USB drive and MacBook Pro (previous gen) all play well together.

However, it's basically useless to me. I have 176GB to back up during the initial backup. Since TimeMachine starts from scratch any time it's interrupted in the initial backup and it looks like it'll take 2 days to complete, it will likely never happen. I suppose I could try it over the weekend (I take my laptop into work). (Many TC owners use an Ethernet connection for the initial backup, although USB drives connected to the AE base have always been reported as very slow (relatively - appx 6MB/sec max often mentioned). Which is why I still prefer my FW800 drive for TM/backups-Mike)
I tried doing an initial backup via USB, then continuing via wireless, alas, this doesn't work either. Sigh. Back to USB only.
-Russ"

A reader replied to Russ' post with a Tip:

"(for Russ)
Try excluding almost everything from TimeMachine for the initial backup. It will then complete in a reasonable amount of time, even over wireless.
You can then disconnect the drive from the AEBS and connect it to your computer. The machine should recognize the disk for TimeMachine backups, and you can include all the items you excluded and let it run at full* speed via a local USB connection.
(*It won't be really full-speed because the AEBS will have created a sparse disk bundle for the backup, which is slower than directly writing to the disk. This is why you can't start it via USB: a regular time machine volume is a regular volume with the time machine data. The network versions need to have the time machine data in a sparse disk bundle.)
-David"

FYI - the next day Russ sent a favorable reply, but then a later mail noted problems:

" Hi Mike, A quick update... This worked perfectly! The backup easily finished overnight and I'm now able to continue incrementally via wireless. Thanks for the exchange of information!
(However he later wrote)
More info on getting a large volume to back-up over wireless. Maybe this technique won't work. Here's what happens when I try it:

1. An initial wireless backup is initiated with all but a small amount of data selected so that it happens quickly.
2. Dismount the AirPort disk and plug it in via USB. You can see the sparse bundle located at /Shared/Laptop_name_xxxx.sparsebundle.
3. Attempt to do another backup initially fails with not being able to mount the backup volume.
4. Go into Time Machine Prefs and select the backup disk volume.
5. Kick off another backup.
6. This time, the backup creates a backup folder at the root of the backup drive called Backups.backupdb.

So unfortunately, directly connecting the drive creates a different backup location on the drive. I wonder if I'm doing something different from what the poster who responded earlier tried.

I also tried manually mounting the sparsebundle, but get this error when trying: "The following disk images failed to mount Image:ÊLaptop_name_xxxx, Reason: Operation not supported on socket"
Sigh, back to the drawing board.
-Russ"

David replied to the above:

"Ah. I think he would need to move the Laptop_name_xxxx.sparsebundle to the root level of the disk and do the backup, then put it back for the AEBS. I'm running mine over the network to another 10.5 machine and the sparsebundle is at the root level of the share.
Another approach might be to just hook up the computer to the AEBS via ethernet which should be faster than wireless.
-David"

(added 3/26/2008)
"EVERYTIME Time Machine starts a backup to my 1TB Time Capsule, it fails. Error dialog comes up to disconnect all. And EVERYTIME this disconnects my internet connection wirelessly. My Airport menu icon says full strength, bit nothing. I can't even connect to the Time Capsule Airport with Airport Utility. It doesn't see it.

I have to unplug the TC and reboot it. And most times my MBP too.
Large threads on Apple Discussions of this TC/TM failure. (For those interested here's the Apple Time Capsule Discussion Forums)
All the computers connected to the TC via ethernet never lose the internet connection. Only the wireless side.
I personally feel the load of a backup wirelessly, overloads the Airport and it just chokes and shuts down.
As it is, TM/TC is off and is a waste of time.
All updates to computers and Airport. MBP using the N standard.
TC is defective.
-Danny"

Have you contacted Apple support about this? Some seem happy with it but most I think do the initial backup using Ethernet (much faster)... And of course the typical (big name website) 'reviews' are usually full of praise. (I use a MiniStack v3 for my TM backups, using direct connect FW800. The builtin powered USB/FW hubs are a nice plus too.) I already had a AE N base (w/Gigabit) so I preferred the MiniStack option (w/1TB HD, partitioned into several volumes). I had mentioned previously that in the past 2 months (before the latest Airport updates) I had occasionally (1 or 2 times a week) seen the "you are not connected to the internet" errors at times (airport signal strength full bars) with my AE N (gigabit) base but knock on wood since the recent updates have not seen that happen again.

(added 3/25/2008)
"AE 7.3.1 firmware report
I applied the latest round of OS and AirPort updates to Leopard (Mac Pro '08, Intel Mac Mini, MacBook) and my AEBSn (GigE). Encouraged by reports of Time Machine working with USB hard drives attached to the AEBSn, I thought I'd give it a go. I had been backing using Time Machine up to the same drives attached to a Mac mini running Leopard, and it's been working fine, but since I really only use the mini as a file server for backups, I was hoping that the AEBSn could replace that functionality, and then I could retire the mini.

I had 3 recent model OWC drives attached to the mini: a 500GB for media files (primarily video), a 750GB to back up the 500GB and the MacBook, and a 1.5TB (stripped RAID) to back up the Mac Pro. All disks were formatted with GUID partitions and HSF+ (Journaled). I attached a powered 4-port D-Link USB 2 hub to the AEBSn, and configured the AEBSn to share disks with "basestation password" and read-only guest access. I re-formatted the 750GB and 1.5TB disks (GUID and HFS+ journaled) and plugged them into the USB hub. I kept the data on the 500GB drive and simply plugged it in to the USB hub.

Initially, I played around with copying files to and from the 500GB drive. Performance was around 10MB/sec with the Mac Pro (attached via GigE). It was about 1/3 of the performance that I saw with the same drive attached to the mini via FW-400, but I didn't expect the AEBSn to be a performance screamer. Since there's only entertainment media on there (i.e. it isn't "mission critical" data), the performance was just fine. Playing video or audio via iTunes from the mounted drive works perfectly - no hiccups. And streaming video to an AppleTV (via iTunes on the Mac Pro) works just fine as well.

There were no problems using the 1.5TB drive as a Time Machine drive for the Mac Pro, nor were there any problems using the 750GB as the TM drive for the MacBook. The initial backup took quite a while, of course, and it averaged around 6MB/sec (both with the Mac Pro and MacBook initial backups).

One (nasty) thing I did notice was that the filesystem becomes "corrupted" (at least as far as Disk Utility "Verify Volume" is concerned) if a drive is mounted by the AEBSn, and then checked with Disk Utility on the mini afterwards. Here's a snippet of the Disk Utility log after I had formatted the 750GB drive, plugged it into the AEBSn, then plugged it back into the mini (of course, I did the proper unmounting of the drive before disconnecting from either the mini or the AEBSn):

2008-03-21 14:12:41 -0400: Checking Extended Attributes file.
2008-03-21 14:12:41 -0400: Incorrect number of Access Control Lists
2008-03-21 14:12:41 -0400: (It should be 0 instead of 1)

That message is troubling (and is highlighted in red in Disk Utility), but it doesn't really seem to cause any problems (at least in the last few days). Weird.

Additionally, there's something new going on with TM with regards to mounted shares... I don't know if this is related to the use of AirDisks on the AEBSn as compared to the mini, or if it's got something to do with the recent TM update. Let me explain...

In my old setup (drives mounted on the mini, and shared to the network), I had to mount the network drive on the Mac Pro or MacBook, and then TM would see it, and start it's normal incremental backup work. If the share wasn't mounted, TM would patiently wait until it was before starting a backup.

In the new setup (drives mounted on the AEBSn, and shared to the network with the basestation password), backups will occur regardless of whether the TM share is mounted or not! This surprised me - the sparse image for the backup will "magically" mount on the Mac Pro and MacBook, but there is no sign of the TM volume being mounted (I have "Connected Servers" set up as a "Show these items on the Desktop" preference for the Finder, so I can see when drives are mounted or not). Very odd... of course, the share must mount deep in the OS somewhere, but the Finder only shows the sparse image mount. Very cool - I believe TM will automount the AirDisk volume, mount the sparse image, do the backup, unmount the sparse image, and then unmount the AirDisk volume. I'm not sure if this behaviour is because I chose the "basestation password" as an option for sharing the disks, or if it will also work if a "disk password" is selected.

I don't have the time to check if it's because the disk is plugged into the AEBSn or if it's the new TM software update that allows this really cool behaviour of not requiring the share to be mounted before TM can access the sparse image. In the end, it wasn't a big deal to have to mount the share first, but now I don't need to have the share mounted all the time (and can ditch the Login Items entry to mount the TM disk). And, well, it behaves much more like a "good network citizen" now (i.e. only mount the share when it's required, rather than always keeping it mounted).

Just for interest's sake, I'm using Backup (the .Mac application) to back up my media from the 500GB drive to the 750GB drive. I have that set to run from the Mac Pro once a week in the middle of the night, and the first full backup ran just fine. However, I don't know if Backup will automatically mount the two drives - I hadn't discovered the "TM automount" behaviour, so I had all the drives mounted when Backup kicked off. I think I'll leave them unmounted next weekend and see if Backup will automount them too (I have a feeling it won't, but I can dream...)

The other new behaviour is occurring on my MacBook. I have File Vault turned on for my account (the only account on the MacBook). For the initial backup, it behaved as it did before: while logged in, it backed up everything outside of the home directory, and only backed up the home directory when I logged out. Now, however, it appears that the subsequent backups are being done while I'm logged in! This is a new (and quite desirable) behaviour for File Vault accounts - now, I get a true "one hour" snapshot, rather than a "logout snapshot" like with the old version. Since the File Vault is a bit of a weird beast when it comes to TM, and since I don't really create much data on my MacBook, I don't know if this is behaviour that only happens if a little bit of data is created (and a single sparse image stripe can just be copied) and won't if a lot of data has been created, or if this is just the way it'll be from now on. In any event, what I've seen so far is really nice. I was OK with the old behaviour, but since I don't log out of my account very often on the MacBook (I mostly just put it to sleep), TM wasn't as useful as it could have been. Now, it seems like it works just like a non-File Vault account (with the exception of the initial backup).

That, and the AEBSn sharing seems to be absolutely rock solid so far... It was pretty dodgy with the older firmware - disks would unmount for no reason, speeds would plummet to a dribble, AEBSn would lock up - which is why I gave up on it before. Now, with the latest firmware, it seems that all the problems have been fixed. I've transferred about a TB or so to and from it over the past couple of days, and it's been flawless. For what it's worth, I also use the AEBSn as my only router (connects via PPP through a DSL modem to my ISP, it's the DHCP server for the network, I have a couple of ports forwarded - no DMZ host - and I'm using 5GHz wide 11n-only wireless).

Overall, I'm exceptionally pleased with this update: not only does the AEBSn now support Time Machine, but it also seems (so far) to be reliable enough to ditch my file server. However, I'm going to give it another few weeks of use before I decide to retire the mini...
-Peter T."

(added 3/25/2008 from 3/22 email)
"I've noticed some network slowdown while doing a Time Machine backup. First, I connected a LaCie disk and tried to delete my old time machine backups because they don't play well together. After I hit the delete button, a few seconds go by and the AE dies. My connection is disrupted, along with all ethernet connections. The Base Station doesn't even show up in my airport menu. I had to unplug the AE and plug it back in.

I've been backing up for (forever) a couple of hours. I'm about halfway done. I logged onto my video game on a pc that is connected by ethernet and I noticed I was lagging and my ping would fluctuate a lot. It seems there is some kind of issue with network slowdowns in relation to time machine.
(Wireless backups (and USB Airdisk's) are going to be slow - what's your network setupmode? (G? N only?) - often around 6MB/sec (sometimes less, some claim a bit more). A reader below said it took appx 24 hrs for Time Machine to backup 78.24 GB at 802.11g speed. Or are you using an Ethernet connection to the base (from machine to be backed up). (I use a directly connected FW800 drive for TM.)-Mike)
(he later replied)
Sorry, I didn't clarify it well enough. I realize the wireless was slow. What I was talking about was the speed of the OTHER computers attached to the AE. While Time Machine was backing up, my other computers connected via ethernet were lagging.
-John"

I have TM turned off (no auto-backups) and use the "back up now" option as needed. (But again I'm also using a direct connect FW drive so it's not taking up my Wireless bandwidth, but I just don't like the hourly, etc. auto-backups although there are some utils to modify that, I prefer to manually select when to backup. (Once daily typically.)

Can't reinstall OS X 10.5.2 Combo Updater: (Note - this is due to the TM/Airport Update 1.0 changing the OS X build number - which causes the 10.5.2 Combo Updater build check (pre-install script) to refuse to install.

(3/25/2008 from 3/22 mail)
"TM and Airport Update
Though I only have old AirPort Extreme (mushroom) connected using lan cables to intel iMac and G4 but wireless to a PC, I downloaded via software update and installed TimeMachine & Airport Updater 1.0. All seems nothing changed except that I cannot re-install 10.5.2 combo update (downloaded from Apple). I got the error message: "You cannot install Mac OS X Update Combined on this volume. This volume does not meet the requirements for this update."
I'm sure I can re-install 10.5.2 combo update whenever I want before the update.
-CK"

I posted this in the Mar. 26th news page and got replies with notes on the TM/Airport Update bumping up the OS X build version, which causes the 10.5.2 Combo update installer script to refuse to update the volume. (See replies in main site post on Can't reapply OS X 10.5.2 Combo Update after TM/Airport Update.)

(added 3/25/2008 from 3/21 mail)
"AE 7.3.1 firmware report
I'm experiencing an issue where the airport extreme is no longer respecting the "enable default host" setting under the NAT tab. To allow outside connections to get through, I must now set up individual ports through the "Port Mapping" tab under "Advanced".
-Cedar"

(Added 3/25, from 3/21 mail)
"I had swapped a Time Capsule for an old Netgear router and immediately had wireless access with my 3 Macs. However, after running the Airport Utility setup and enabling WPA/WPA2 Personal, neither my G4 Quicksilver running 10.3.9 or my G4 Cube running 10.4.11 could connect to the wireless network. They could see the network but would fail to connect after entering the password, saying there was an error. My Intel Mini running 10.4.11 was able to connect without any problems.
After installing Firmware 7.3.1, all 3 Macs can now access the wireless network.
-Larry"

(3/20/2008)
"Mike, Downloaded and installed the updates and firmware update.
Both my sons' iMac G5's and my wife's MacBook's Time Machine recognizes the attached 500 GB HD, but ONLY after the AirDisk volume was mounted on the Desktop.

My wife's MacBook backs up directly to a USB 2.0 HD. My sons will use the AirPort Extreme (Fast Ethernet) attached 500 GB AirDisk for its Time Machine backups. I just got home from work, so I'll email back after I wake up and let you know how it went.
(he later wrote)
It took approximately 24 hrs. for Time Machine to backup 78.24 GB at 802.11g speed.
-Fabian"

Speeds are typically around 6MB/sec max with AE base connected USB drives (based on past reports), so it's not very fast but it is nice that apple finally enabled that. (I use a FW800 drive for TM.)

" Same for me... (AirDisk working with Time Machine after firmware update.) Using USB Lacie 500GB Big Disk ... transfer speed 5+MB per second
-Kevin"

The reader that first reported AirDisks working (3/19 post) for Time Machine after the firmware update sent a later mail:

(3/20/2008)
"Time Machine appears to be working as advertised. I'm up to 12GB of a 67GB backup. Thru put is relatively slow with the airdisk... 2-4 MB/s. I think after the first backup is done the speed won't be too much of an issue and the wireless connecting a big plus.
-George"

BTW: Ken Lo wrote with a note for those that still can't get TM to recognize their Airdisks to check the AirDisk setup/config - saying that Secure Shared Disks With a disk password are recognized, but not Secure Shared Disks With accounts.

Also a reader that previously had reported NAT Port Mapping problems w/7.2.1 firmware said the 7.3.1 update seems to have helped:

(3/20/2008)
"A follow up to this: the new firmware for the AEBS released today (version 7.3.1) seems to have fixed the NAT-PMP issues I was having. I had hard-mapped ports set up in AirPort Utility for uTorrent on WIndows Vista with 7.2.1. Today, after updating the AEBS firmware, I removed the port mapping and changed the port uTorrent was using and the port was mapped automatically by uTorrent using the NAT-PMP protocol.
I also tested the mapping from MacOS using Cabos, and the mapping was also automatically mapped by the application using NAT-PMP.
-Fitz"

BTW - one reader said he's seen some TimeCapsule "slowdowns" and dropped Airport connections after yesterday's updates and asked if anyone else had seen that. (I wrote to ask for more details on his network/setup). I don't own a Time Capsule but have seen no negatives so far from the updates on this AL iMac (10.5.2 w/all updates) and a (gigabit) AE N base (running 5GHz mode currently for best performance w/AL iMac and Apple TV.)
In the past (last couple months) I had seen (a couple times a week perhaps) before this update I'd get a "you are not connected to the internet" error at times (safari during attempt to load a web page - airport signal strength never dropped) - rare but happened once or twice a week for the last month or two... too early to tell if these these updates affected that.

(from 3/20/2008 news page) The Time Machine and AirPort Updates v1.0 - as with some previous Airport Extreme updates, a reader said this update included a new firmware file for his 802.11n broadcom chip based adapter. (As mentioned on the original Mac 802.11N info/adapters page here the OEM Mac Pro (mini-PCIe) card (and some intel-based iMacs) used a broadcom chip, the notebooks typically used Atheros AR5008 based cards - at least in the past. Not looked at the pkg to see if there's updates to them also.
I didn't check the version of the Airport card firmware on this AL iMac before applying the update, but afterwards ASP shows the same thing he say "Broadcom BCM43xx 1.0 (4.170.46.5)". (If the update is a file (loaded during boot) as before, booting from a volume not updated would show the previous version number.)
Another reader said he's seen some performance improvements:

"TM and Airport Update 1.0
This update seems to have fixed the large file transfer slow-down issue a lot of people, including myself, were experiencing. The workaround up to this point was to use a delayed_ack hack. I updated both my laptop (MacBook Pro) and server (dual G4 tower), disabled the delayed_ack hack, and attempted a 2.71GB download to my laptop from my server. Ten minutes later (~4.5MB/sec), the transfer was complete. Previously, without the hack, I couldn't get more than 200MB or so into the download before the transfer rate would slow to a crawl (less than 100kB/sec).
-Alan S."

(3/19/2008)
I just installed the Time Machine and Airport Update v1.0. Installation was uneventful and after a few minutes my Gigabit Airport Extreme offered a firmware update. Upon applying the firmware update, time machine could see the attached usb drive and is currently backing-up over a wireless connection.
(he later wrote
Time Machine appears to be working as advertised. I'm up to 12GB of a 67GB backup. Thruoughput is relatively slow with the Airdisk... 2-4 MB/s. I think after the first backup is done the speed won't be too much of an issue (for incremental updates) and the wireless connecting is a big plus. -George"

Two other reader also said TM finally works with their Airdisks now. (Previously Time Machine would not support Airdisk's without the hack/mod listed here last month.) I welcome other reader feedback on this firmware update.