Archive for December 31st, 2007

Another year over…

I’ve read a few “this was my year” blog posts in the last day or so; no doubt I’ll read a few more in coming days. I honestly can’t remember much of positive significance happening this year, compared to last year (which was huge). For a few reasons though, I am glad that this year is nearly over and that a new one is about to begin.

I can’t say I’m disappointed about 2007, although I do feel I would like to have “achieved” more. From a work perspective, I did no conferences, and I wrote no papers. I did keep some servers from failing, though, and helped a few folks with some problems they had.

I think it’d be great to understand why folks attach so much significance to the change of the calendar. The symbolism of “turning a new page” happens every day; why do we disregard that and think only of the new Year? It’s no wonder so many folks fail in their New Years Resolutions — the intimidation of having to keep to a promise you make yourself for a whole year is enormous! And we never choose anything simple, do we? Resolutions are always “lose thirty kilos in time for Gracie’s wedding” or “stop smoking” or “try and be a better person”. Achievability is sacrificed in the face of having to make a huge gesture in the face of tons of brightly-coloured explosives going off in the air above us (or on the television in front of us).

So, for me this year, I am making one New Year’s Resolution: to not make any New Year’s Resolutions. I’ll be making New Days Resolutions instead — every day, I will think of something I can do with that day. When I do it, I’ll be able to enjoy a little celebration of having achieved my Resolution. But what to resolve? Well, little things that add up to something big. Fixing my corrupted LDAP database, for example (for Susan to get her address book entries back). Taking myself out of the house and walking (to improve my health). Cooking dinner for the family (without being asked). Ringing family and friends for a chat, without having a reason.

The best part of this plan is that by the end of January, when I’m surrounded by miserable folks bemoaning the demise of their New Years Resolutions, I’ll have celebrated thirty-one Resolutions and be feeling great! :)

Some of you reading this are saying “hang on, those ‘Resolutions’ are all stuff that people do every day, how can you make Resolutions out of that?”. Well I’m sure many people do these things daily, but they’re not me. Everyone’s life is what they make of it, and many of us (me included) need to realise that a little effort trying to do big things doesn’t work — what’s needed is a big effort on the little things.

The best thing about 2007 for me was feeling signs that I’m getting better — getting my head out of whatever place it’s been in the past few years. Work still sucks, and is actually getting worse, but that’s not the crushingly depressing thing it would have been two years (or even twelve months) ago. If 2008 holds more of the same improvement then that’ll be fine with me.

Happy New Year, readers… Best wishes for prosperity and happiness, wherever you are and whatever you wish for!

PoE again: this time, success!

I had pretty much forgotten about improving on the Power over Ethernet progress I mentioned previously. A couple of weeks ago I bought another 7970 that I successfully converted to SIP to run in the study, and I was considering buying a few 7961s or Linksys PoE-capable phones to use in other places. However, I got an e-mail from a reader whose success at using a hacked cable with his 7960G prompted me to have another go.

While I did a heap of research about PoE and IEEE 802.3af, the hints I got about using a hacked cable with a standard 802.3af switch to power a Cisco phone came almost exclusively from the voip-info.org wiki. Everything I’d seen about this trick relied on the use of a crossover cable to fix the problem where the phone using the Cisco pre-standard expects the power in the opposite polarity to that delivered by 802.3af.

When I’d had a go previously, the info I had told me that I had to get power onto the spare pairs in the Ethernet cable, because the Cisco pre-standard used the spare pairs for power and not the data pairs. This was a problem as my switch provided Type A PoE, which is power-over-data-pairs. In the end I figured that I’d have to come up with some kind of electronics to get the power off the data pairs and onto the spare pairs.

My friendly reader informed me, however, that Cisco pre-standard phones take power from the data pairs as well as the spare pairs! Nothing I’d seen indicated that this was a possibility. So I pulled out the hacked-up cable I’d used previously and gave it another try… but it didn’t work.

I tried a bunch of alternatives that I probably tried before as well. I tried putting the sense resistor across the spare pairs instead of the data pairs, I tried switching the spare pairs around. But, since others had only ever reported success with a crossover cable, it had never occurred to me to try a straight cable instead. A bit of resoldering later, another try, and it worked!

Tried it with all my 7960s and it worked fine. So it looks like some 802.3af switches put power on the pairs in the opposite polarity to others (which is not a problem usually, as 802.3af devices have a bridge rectifier that allows them to handle either polarity).

Thanks to my friendly reader, I now have a way to power all my Cisco phones via PoE! Yay! The only caveat (one that I’ve only seen briefly mentioned anywhere) is the extra load placed on the cable by the 25kohm sense resistor — doubt it’s significant, but over a few phones it might add up.

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