Friday 23 November 2007

Standards Matter

No I'm not getting all conservative in my old age but I've fallen victim to two examples of declining standards in the last 24 hours and I feel the need to vent.

The two standards that have failed for me are the 802.11 alphabet soup of wireless lan specs and the eSATA standard for connecting external drive peripherals. I bought equipment in reasonably good faith, checked in advance that they claimed to support standards that would mean I could use them but when I tried to use them yesterday I found once again that some standards just aren't. This is not a huge surprise as I've had years of pain working with 802.11 in an Enterprise environment but I was very disappointed to see that things remain just as bad in the consumer field.

The gruesome details:

I bought a D-Link DIR-655 Gigabit Ethernet\802.11b/g/n router and a D-Link DWA-556 802.11b/g/n adapter for my desktop PC. Setup is simple and straightforward and I got these two plugged into my network and talking to each other at 60+Mbps without much trouble. The problem came when I attempted to connect my new Dell M1330 laptop running Vista 32. It sees the network and I can configure the settings for it (WPA2 \ AES 802.11g) but it instantly fails during the handshaking process. I upgraded firmware on the D-Link router to its most recent 802.11n (draft 2) version, selectively disabled every single WiFi extension I could find (802.11d, WMM, QoS, WISH, played with Guard Interval, disabled 802.11n\g mode and set it to 802.11g, then 802.11b/g and then dropped all the way back down to 802.11b. All to no avail. The Dell uses the Centrino (2) 3945 a/b/g Mini PCI adapter and I dug into its settings again selectively disabling things like "Enhanced Throughput", WMM, 802.11a and then 802.11g. Again all to no avail.


The part about this that is really nuts is that the 802.11 specification provides a capability advertising and negotiation feature that should have meant that I would never have to know any of the above details. The access point \ router broadcasts its capabilities using things called beacon information elements and the client should choose the best features it can support when handshaking. Everything should work but unfortunately the vendors have repeatedly forced through crap in the standards (opt outs that allow them to build cheaper crap) that means that this auto negotiation doesn't work and is often the root cause of problems rather than the hugely useful feature it should be.


I've now installed Ubuntu on the Dell and will be trying to see if that gives me some additional options later today. I'm not hopeful though as I think this is a firmware level incompatibility and has nothing to do with the OS.

Edited to add: The WLAN compatibility issue gets a bit weirder - I have now set up a profile on the Dell to connect to the D-Link 802.11n router that I couldn't connect to under Vista. It looks as if it is having similar issues as the WLAN connection "throbber" is still spinning away but I am actually connected to it right now. Maybe it is an Intel driver problem more than a D-Link firmware problem.

The eSATA problem is much simpler but equally annoying. I bought a 750Gig Seagate FreeAgent Pro a few weeks ago as a secondary backup device. It supports USB 2, Firewire 400 and eSATA connectivity which is why I spent the additional 40 Euros on the Pro model. It came with both USB and Firewire cables and they work perfectly however the data rate over both interfaces is limited to around 30-35Megabytes/Sec even though the drive itself should support rates of up to 60/70M/sec on its outer sectors. I hoped that with an eSATA connection I would see the drive perform much closer to its actual spec so I ordered an AKASA e-SATA cable to test it out. It doesn't work. Hot plugging just does nothing and attempting to boot the PC with the drive connected over eSATA causes it to go into some never ending loop during the boot process. Some online research (which I no know I should have done first) indicates that eSATA is very fussy and you must get a good quality cable or you're doomed. Searching the Interwebs seems to indicate that Siig make eSATA cables that actually do work so I'm going to try and find one of them somewhere (PC-World\Dixons are the UK and Ireland agents amazingly enough).

1 comment:

noegruts said...

I wouldn't be in a rush to buy that replacement eSATA cable. It looks like the FreeAgent Pro line of drives have some more fundamental problems with their eSATA interface:

http://blog.noegruts.com/2007/12/seagate-freeagent-pro-esata-problems.html