Crossed Wires

Vic’s Blog

Travel update: Arriving in Europe

Nov 7

Posted by Vic in Travel | View Comments

Time to fill in a little bit of detail from my travel so far.

I arrived in Amsterdam on Sunday morning, and decided that rather than get bounced by the hotel trying to check in too early that I’d fill in some time at Schiphol Airport.  While I was there I had a chance to reflect on the flight over from Hong Kong.

My stop in Hong Kong turned out to be just long enough to create a risk of me missing the flight.  I was sitting in a comfortable chair in the lounge and getting occasional snacks and drinks, and successfully dozing for ten or fifteen minutes at a time.  Our boarding time was delayed by about an hour, and whether I became just a bit more relaxed because of the delay or because the noodle dinner I had settled in my stomach I ended up falling into a proper sleep.  Like many airlines overseas, Cathay Pacific doesn’t make boarding announcements in their lounges…  I awoke to find the departure monitor flashing “Final Call” next to my flight.

The terminal building of Hong Kong’s Chek Lap Kok Airport is shaped a bit like a big letter-Y with an upside-down capital-T overlaid.  You guessed it, to get to my flight I had to go from the tip of one arm of the T (where the Cathay Lounge is located) to the fork of the Y (where my departure gate was).  Doesn’t sound like far, does it: perhaps I didn’t mention that this munged-up T-Y shape got stretched out in the middle and is about three-times longer than it is wide…  As I fast-walked along travelators, I kept looking at monitors and expecting the dreaded “Gate Closed” to appear.  I drew closer to the gate, and could see no queue of people waiting to board–now I knew I was pretty late.  I saw someone in a green uniform starting to walk away from the gate toward the main terminal building (toward me), and as I got closer I saw that she was carrying a card with my flight number on it in large letters.  At this point I relaxed: they’re still looking for the latecomers.  I waved at her when I realised this, and when I reached her she asked my seat number.  It looked like I would be okay.

When I finally got to the gate I saw that I did actually have a bit of time available: the queue was actually on the aerobridge waiting to actually get on the plane.  It took at least five minutes in the bridge before I was on the aircraft, so it wasn’t like I was keeping them from closing the doors.  Still, a bit of panic to teach me to be careful about being inattentive in an airline lounge.

The flight was bad.  Actually I take that back: in the context of other long-distance flights I’ve taken it compares badly, but really it was probably just your normal Cathay Pacific long distance economy-class flight.  Cathay’s seat in Economy though is weird: it’s actually a little enclosure, a bit like a discount version of the Qantas Business-class cocoon.  What’s weird is that the seat doesn’t recline, instead the seat cushion slides forward and back.  The bottom of the seat back is attached to the back edge of the seat cushion, and the top of the seat back slides in runners in the seat frame.  So the angle of the seat back does in fact change, but for someone tall like me instead of being able to actually recline with a straight back I got curled up by the crazy thing.  The only good thing about it is that it eliminates that feeling of intrusion you get when you want to sit fairly straight but the person in front wants to recline all the way back.

The arrival into Amsterdam’s Schiphol Airport was uneventful.  The reason we were delayed from departing Hong Kong was actually so that we didn’t arrive too early to be allowed into Schiphol; the flight time was about an hour shorter than scheduled.  So even though we left late, we arrived on-time (if not a bit early).  The arrival hall in the airport was a mess however: I’m sure that they put us into the smallest passport hall in the place, and our full 747 from Hong Kong arrived at the same time as a United flight from the US.  The place was packed–they had to switch off the escalator into the hall to stop people from getting jammed into this room like sardines.

After I made it out to pick up baggage I waited another 10 minutes or more.  I had thought that the length of time it took to get through passport control would have given plenty of time for the bags to get off the plane, but it wasn’t so.  It took almost an hour to get landside–perhaps the messiest arrival at Schiphol I’ve ever had.

I decided to save some time for the next day and went to pick up my ticket for the train to Paris.  The airport terminal is actually built behind the railway station–if you were to arrive at Schiphol by taxi for the first time, you’d be tempted to think that the taxi driver misunderstood and took you to the train station instead of the airport.  Entering through the front doors, you have to walk past all the railway kiosks and ticket machines and timetables before you get to anything that even remotely looks like something to do with air travel.  I’m a train-guy though, so I like it that way. :-)

I am so much a train-guy in fact that after I had some breakfast I decided to throw my bags in a locker and hop on a train to fill in some time.  I went to Utrecht, which I thought would be an hour or so away and would fill in a nice chunk of time, but actually only turned out to be 30 minutes away.  On this little trip I saw some Dutch countryside and was stunned at how green it looked.

When I got back to Schiphol I picked up my bags and got the airport shuttle to the hotel.  ”Yes, sir, your room is ready”–how wonderful those words can sound when you’re tired and filthy from a long plane ride!

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Back in the saddle again…

Oct 31

Posted by Vic in Life, Travel, Work | View Comments

This post comes to you from the Cathay Pacific lounge in Hong Kong airport.  Around 8 weeks have passed since my last post, and I’m pretty disgusted with myself at how little (read: not at all) I blogged when I was in the US and China.  In fact, by the looks of things the site has been down for most of the time anyway, which is also pretty disappointing.

I’d love to break my blogging drought now, as I have about five hours before I board my next flight, but I have a splitting headache which I’m sure you understand is not conducive to effective computer usage (which is a shame, as the Wi-Fi here is excellent).  Maybe later.

By the way, what brings me to Hong Kong?  I’m going to Europe for my remaining ITSO Workshop presentations.  Amsterdam on Monday, then Montpellier (France) on Tuesday.  I make some things up for a few days, then London next Monday followed by Milan on Thursday, then flying home via Rome and HK (again, three fortnights in a row).

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Doing the New York thing

Sep 7

Posted by Vic in Travel, Work | View Comments

(okay, so after fixing the blog now that I discover it’s been down for two days, I might as well update it…)

I’m in Poughkeepsie for a couple of ITSO projects. For the last week I’ve been working on the development of material for the ITSO’s Workshop World Tour. I’m helping out with the “System z Virtualization” stream, and I’m lucky enough to be presenting in a half-dozen cities around the world. Only problem with that is that the first one is only a few days away, and the material probably needs a bit longer in the oven (so to speak). Still, I’m looking forward to the event as a way to help build the Linux on System z community (and to do a bit of travel to some new places).

Starting this week I’ll be doing a residency with the ITSO. The book will be “Security on z/VM” — I don’t know if it was made so open-ended on purpose, but there’s a lot that could go into a book with that title so I’m looking forward to a busy time as the project develops.

More on my US travel as I get settled (I’ve been here a week and my sleep is still all wrong).

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Upgrading from Cisco

Aug 21

Posted by Vic in Hardware, Telephony | View Comments

In case you weren’t aware, I am a VoIP nutcase.  I have an Asterisk phone system at home, and all the phones in the house are VoIP of some description (either real VoIP devices or analogue handsets through an ATA).  While I haven’t converted to VoIP as a replacement for PSTN, I have some connectivity to VoIP providers both here and overseas (and soon to be more, to help the phone-home situation while I’m overseas).

I’ve been a user of Cisco IP phones, buying 7960s and a couple of 7970s through a well-known internet site (maybe it starts with an “e”, not sure).  The phones have been excellent, and I’ve even written a few XML apps to supplement their use here.  The 7960s are getting a bit dated now, however, and I found myself contemplating buying 7971s (or even something newer, like the 7965 or 7975).  Before I committed myself further into the relationship with Cisco, though, I thought about what I was really getting out of using Cisco phones.

Like many users of second-hand Cisco gear, I only purchased the hardware.  I do occasionally succumb to a nagging feeling of being an “outlaw” (at least in the eyes of Cisco), but admittedly that feeling usually only comes when I find out that Cisco has released another new version of SIP software that I can’t get because I haven’t paid for SmartNet.  The last time I had this thought though, I had a realisation: even if I did pay for SmartNet, the only thing I’d get would be the firmware: Cisco will only support their phone software when connected to their CallManager server (yes, even the SIP firmware).  Anyone running Cisco phones against anything other than CUCM gets no support from Cisco in the event something doesn’t work–and based on the information floating around, the problems are many.

So basically I would be paying Cisco to allow me to run one of the worst SIP implementations in embedded existence, with no opportunity to report problems with it in my environment.  Hmm, let me think about that for a minute…

At around the same time, I happened across the NerdVittles site, and in particular the post where NerdUno nominated the Aastra 57i as the “World’s Best Asterisk Phone“.  I started to do some research into it, and was astounded at the level of support the manufacturer (a Canadian company which a few years ago acquired the telephony business of a little mob called Nortel) and the community provide for this phone and Asterisk.  Looking through the phone manual, I found functions that only work with Asterisk! I found a full set of integration scripts that provide XML applications, right through to automatic provisioning tools.  Possibly the best thing was that on the product page for their phones — right there on the page that descibes the product — are links to current versions of firmware, documentation, XML application development guides, even a Linux-based application to encrypt the phone configuration files.  Not hidden in some obscure hard-to-find portal, or behind a registration-only support site.

I started to think of the possibilities…  I’d be able to freely modify the phone configuration (even via a HTTP interface if I so chose), without having to make trial-and-error changes to a cryptic and totally undocumented configuration file.  I’d be able to write XML apps without having to do laborious debugging to cater for why the parser was choking on XML that was perfectly okay according to the documentation but apparently tripped over an undocumented field length restriction or character encoding limitation.  I could get access to things like Visual Voicemail, BLF, integration with Asterisk functions like day/night mode and call parking.  I could keep the phones up-to-date for new functions and bug fixes.  With a click of a mouse I could get proper Australian tones!

So, I decided to give one a try.  Finding nothing on that “e” site I went looking for a vendor locally, and found several places that would sell one to me (legitimate e-tailers, no less!  Zounds!  A VoIP phone with a warranty?  You jest!).  It took a while for my chosen vendor to source it for me, but I’ve had it now for a couple of weeks.  It’s probably going to take a while for it to live up to it’s full potential in my installation, but since that potential is so much greater than what I have been able to do with the Ciscos I think I’m already ahead.

More in the coming weeks as the Aastra settles in.

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Asterisk chan_mobile fail

Jul 23

Posted by Vic in Linux, Telephony | View Comments

I’ve been struggling with setting up chan_mobile on my Asterisk system.  For those fortunate enough to actually get it working, chan_mobile provides an interface for Asterisk to treat a mobile phone like a PSTN or VoIP trunk–when someone calls your mobile phone it can ring your desk phone or softphone, or you can use your normal handset to make an outgoing call on your mobile.  It works by making the Asterisk system look like a Bluetooth headset or handsfree to the phone.  You can even connect Bluetooth headsets to Asterisk using chan_mobile and have them appear like an extension in your dialplan (although that capability doesn’t seem to be covered very much).

I figured this would be an ideal way to make use of an old Nokia 6230 with a broken speaker.  Somewhat foolishly, on the assumption that it would Just Work (and that all the troubles experienced by others would not beset me) I went and bought a two-pack of prepaid mobile SIM cards and went through the adventure of activating them.  One of these SIMs I threw into the 6230, the other I kept on hand for after I got everything working.  The plan, you see, was to be able to take advantage of free calls between the two accounts by taking one of the phones with me when travelling and leaving the other strapped to Asterisk at home.

I think it’s probably fair to say that I’ve had more success with it than a lot of other folk have.  The process of configuring Asterisk to use the Bluetooth dongle is quite straightforward, and it’s even quite easy to configure the chan_mobile driver to have calls enter your Asterisk system in a routable way.  When I dialled the “tethered” mobile from another phone, I was rewarded with the ringing of my desk phone–and at this point, I think I gave myself the kiss-of-death.  “Wow, that was easy,” I thought…

When I picked up the desk phone, I was rewarded with silence.  Not just the silence of the phone not ringing any more, but also the silence of no audio being passed either way over the call path.  Nothing put the pure, desolate sound of FAIL.

Things actually went downhill from there, believe it or not.  I have tried a total of four different Bluetooth dongles, with results ranging from the aforementioned signalling-but-no-audio to why-the-@#%$-won’t-this-thing-pair.  The three different phones I’ve tried elicited a similar spectrum of results.  “Make sure your dongle has a Cambridge Silicon radio, they definitely work” say the forum experts…  Sorry guys, one of the biggest failures I had–failure of Asterisk to pick up the call–was on the last dongle I tried and, yes, it was a CSR.  I’ve even had two different versions of the bluez stack and (I think) two different asterisk-addons versions.

The one thing that I’ve distilled from all the experiences I read through is that there is a ridiculously high level of sensitivity to particular phone and dongle features.  For example, great success has been reported with the Nokia 6230i.  I figured that I was lucky and that a 6230 would be close enough…  Doesn’t look like it.  There is one model of D-Link Bluetooth device–no longer in production, by the way–generally reported to give the most success.  Tweaking the device class reported by the bluez stack in the Linux host is said to give success too, but led to me being unable to get a connection to Asterisk.  Unfortunately, I have neither the time nor the patience to spend too much time trying to go through the motions of getting it working.  I tell you, if it really is that difficult to get two Bluetooth devices to talk to each other it’s no wonder that the majority of folks still use wired headsets!

Luckily all this little experiment has cost me so far is time.  The two-pack of SIM cards cost me the grand total of $2, and they had enough start-up credit on them to allow me to receive calls without a top-up.  The handsets are from that ever-growing pile of GSM hardware that just about every modern household is accumulating now (well, at least the ones that house a gadget-freak who can’t even bear to part with a broken one).  The kernel version I’m running on the system could be an issue, since I get ugly error messages from the btusb module when I take a call, so a kernel update might help.  After that though it’s likely to cost real money–buying a new/different Bluetooth dongle, for example.

If anyone out there has suggestions on something else to try, I’m listening (reading? watching?).  I don’t mean to complain, after all I am one that usually subscribes to the “it’s Open Source, it’s the hard work and dedication of others, you got it for nothing, you’ve got no right to complain” philosophy.  It is really frustrating to come away from a couple of days’ effort with nothing to show for it, though.

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LDAP-backed DNS and DHCP…?

Jul 22

Posted by Vic in Linux, Networks | View Comments

I’m having a bit of an infrastructure redesign here at the Crossed Wires campus.  Each time I have an outage (the last one was caused by a power failure) I learn a little more about the holes in my current setup and what I can do better.

I’m implementing a router box on an old low(-ish)-power PC that will be backed up by a virtual machine on my main virt-box.  I’ve already done most of the preparation of using keepalived to implement VRRP, and a colleague has given me some pointers in using the Linux-HA tools like Heartbeat and DRBD to make services like e-mail and Samba redundant.

I’ve had a soft spot for LDAP for ages; I’ve always thought that putting as much backend data into LDAP as you can would be a really good way to get failover and redundancy.  Instead of having to deal with every single server’s different way of doing replication and failover, just bung everything into LDAP and get that replicating.  Sounds good in theory, but in a nutshell it’s not working out that way for the two least-celebrated but most important components of my (arguably any) network: DNS and DHCP.

There are a number of LDAP-backed DNS projects out there.  If I’m willing to go to the bleeding edge with BIND on my Gentoo build I can get access to the two most talked-about ones (bind9-sdb-ldap and the BIND DLZ LDAP driver), and other solutions like PowerDNS and ldapdns are available.  But none of them offer integration with DHCP, and I’m currently using dhcpd’s “interim DDNS update method” to make sure that hostnames are seen in my DNS when a lease is granted (okay, there’s a Perl daemon that goes with bind9-sdb-ldap, but it seems like a sort-of clunky afterthought).

Speaking of DHCP, LDAP backends for it are virtually non-existent.  The only LDAP-enablement I’ve found for ISC DHCP involves putting the config file into LDAP, not the leases…  I actually used that for a few days a while ago and pulled it out because it was actually more work to do it that way (and for no benefit in failover).

It seems to me it would be a project ripe for the picking: take an integrated DNS/DHCP server like dnsmasq and make it write into LDAP instead of to a file.  If I had more free time I’d probably have a go at it, except for the fact that no-one really seems to be that interested in storing DNS and DHCP in LDAP: that it hasn’t been done says to me that there’s no demand for it, and it’d end up being a big waste of time and effort.

Over to you, lazyweb…  Is this a yawning chasm of unfulfilled networking dreams, or a case of me trying to make something more complex than it needs to be?  After all, the rest of the world gets by with DNS master-slave and DHCP failover, they should be good enough for me too, right?  ;-)

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Nokia SIP client: WTF?

Jul 17

Posted by Vic in Soapbox, Telephony | View Comments

I was having a browse around the excellent Nerd Vittles site tonight, and stumbled onto a disturbing conversation about the removal of the Nokia SIP client from S60 Third Edition Feature Pack 2 (as used on recent phones like the N78 and N96).

Nerd Vittles linked to this blog, which alludes to the possibility of mobile carriers putting pressure on Nokia to remove “free” calling capability (i.e. VoIP) from their phones.  Within the comments on that blog post comes a link to a post on Nokia Conversations (I’ve never seen that site before, but it seems to simply be a bit of a PR site…).

“Charlie” from Nokia Conversations tries to spin the changes to Nokia’s SIP support.  Firstly, in what seems to be almost believable at first he says “no, the SIP stack is still there, in fact it is actually better in FP2 than previous versions”.  Apparently, the improvements meant that the integrated VoIP client had to be dropped because it wasn’t ready.  This explanation loses credibility, however, when you see that Charlie’s blog post was made on 27 August 2008: nearly one year ago! And folks are still commenting on that thread, saying “where’s my VoIP client?”.  I cannot believe that it would take Nokia a full year to update the VoIP client and package a firmware update for these phones–especially given that two other S60 3rd-ed FP2 phones released after the N78 and N96, namely the N79 and N85, apparently do have the VoIP client!

On 8 December 2008, Charlie posts a follow-up on Nokia Conversations.  In it he says “well we made some folks unhappy, but we’ve made a fix”.  He points to something called the “SIP VoIP Settings” application that was supposed to bring back what people were asking for.  Problem is, it’s not a VoIP client at all: it’s simply a configuration tool allowing more detailed control over the configuration of a SIP profile.

In the final insult it appears that the new N97, Nokia’s current flagship also has no VoIP client.  The N97 is based on S60 5th edition and not 3rd edition, but 5th is supposedly just 3rd updated for touch-screen anyway (not a significant change in technology).

Looking more closely at the specifications pages for these N-series phones, the tiny-tiny text that says “VoIP” is missing.  It’s probably arguable therefore that Nokia never advertised the phones as having VoIP capability[1], so anyone who bought one without checking has created their own situation.  However, Nokia, why is the “upgrade” to the N95 missing one of that phone’s most popular features?

At one point Nokia’s story changes… it seems that VoIP is a function that doesn’t fit the product direction of N-series and belongs in the E-series phones (indeed both the E75 and the soon-to-be-released E72, reportedly S60 3rd-ed FP2 phones, list VoIP capability).  Why, then, do other S60 3rd-ed FP2 phones like the N79 and N85 have VoIP?

This whole “affair” seems to have been handled really poorly by Nokia.  Firstly, claim a technical limitation.  When that fails (because you discover that your users actually know something about tech), claim that your third-party providers have developed a solution.  When it turns out that the third-party products are steamers that don’t even use the infrastructure your OS provides (something you didn’t know before either), claim that the product has been “realigned” and doesn’t service that market any more–while simultaneously marketing a product in the same series with the same technology that still has the disputed feature.

I must admit to being a lot less angry about this after researching this post than when I started it.  I’m more angry about the survey I completed earlier today when I visited the Nokia website–I was very complimentary about .  My shopping-slash-wish list just lost an item–not that I was seriously contemplating buying the N97, but it’s nice to have a technical reason not to buy it rather than the boring can’t-really-justify-it line. :)

[1] Of course it’s easy to make this statement based on what the product pages look like now…

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Is it catching on…?

Jul 14

Posted by Vic in Uncategorized | View Comments

Mark isgetting an internal server error on http://tinyurl.com/n5fgd9.  I think I amgetting an internal server error too.

Unless, of course, I don’t get it.

(The first result got fixed, this version (courtesy Google’s cache) has the goodness.)

Lifeblog test post (photo fun with Nicholas)

Jul 13

Posted by Vic in Life | View Comments

A spooky pic of Nicholas playing with an LED toy.

Tue 23/06/2009 08:39 23062009081

FreePBX device-and-user mode, part two

Jul 12

Posted by Vic in Telephony | View Comments

In part one, I described how I reconsidered device-and-user mode in FreePBX, and did the initial changeover.  Read on to find out how I overcame a major issue with the configuration!

I have an ISDN phone line coming into my Asterisk system.  One of the indials is for our home number, the other is one I use for work.  Before I found FreePBX, I had manually worked the Asterisk dialplan to have calls made from my work phone(s) appear from the work phone number–useful not just for Caller-ID, but also required for the long-distance provider I use to bill calls for work.  With FreePBX I was able to use a custom context to pre-select a route that dialled the provider override prefix to send the calls through the other provider, but it was a bit of a hack using hand-written dialplan code and a bit of luck.

Before I changed to device-and-user, I naively assumed that FreePBX would allow a user to be associated with a context in the same way a device/extension can be.  This is not the case, and the context of the device is still used for routing.  This meant that I could not use a device for either work or personal calls without having to log onto FreePBX and change the device context (logging on as the work user was not enough).  I was back to square one…

I did a little research.  Firstly, I rediscovered how I was making the existing routing work.  The ISDN interface I use (driven by chan_capi in Asterisk) simply uses the outgoing caller-id of the call to select from available MSNs[1].  So I had one route that had the “normal” MSN set as the outbound caller-id, another route with the “work” MSN (plus the rewrites to add the long-distance override code at the front), and a custom context for the work devices that made only the route with the work MSN available.

Looking more closely at the user definition page, I saw that there is an “Outgoing Caller-ID” field.  By using this field, I was able to do away with the separate route and the custom context and set the work MSN there instead.  This gives me just what I need: a way to control my outbound MSN on a per-user basis!  This got me half-way there, as I still needed a way to set the long-distance override codes for work calls.  A bit more research turned up a predialling macro hook that the FreePBX folks made available.  With a bit of code to test the caller-id and the number dialled (the long distance company doesn’t handle free calls, for instance) I get just what I need.

Here’s the macro hook (this is added to extensions_custom.conf):

[macro-dialout-trunk-predial-hook]
exten => s,1,NoOp(Trunk is ${OUT_${DIAL_TRUNK}}, CallerID ${CALLERID(num)} calling ${OUTNUM} )
exten => s,n,GotoIf($["${CALLERID(num)}" != "xxxxxxxxx"]?endit)
exten => s,n,GotoIf($["${OUT_${DIAL_TRUNK}:4:11}" != "CAPI/contr1"]?endit)
exten => s,n,GotoIf($["${OUTNUM}:0:4}" = "1800"]?endit)
exten => s,n,Set(OUTNUM=1xxx${OUTNUM})
exten => s,n(endit),MacroExit()

So I’m now a happy device-and-user user!

[1] Actually I don’t know if that’s chan_capi doing it for me or whether it’s just the way the ISDN network works.

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