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Sipgate and the Zoom 5801 ATA

Following on from my initial foray into SIP a couple of weeks back, I ordered a Zoom 5801 ATA from Expansys, so I could hook my good old-fashioned cordless phone up to Sipgate.

I wasn’t impressed by the six working days it took to turn up, but it was free delivery.

In terms of hooking it up, the man-traps to avoid are:

  • Your Sipgate password for registering a device is NOT the same one you use to log in to their website
  • You don’t need STUN enabled or configured
  • I’ve got various SIP ports forwarded from my router to the ATA’s IP address, though I’m uncertain if they’re absolutely necessary (Google for the ranges to use).

My router is Virgin Media’s latest Superhub.

    Having configured it all, incoming calls work perfectly, and my twelve quid cordless phone from Argos manages to display the caller ID, which beats both Virgin Media and BT’s landlines hands down. Outgoing calls work too, and don’t forget that Sipgate don’t charge for 0800 numbers (unlike your mobile provider).

    Lastly, since you’ve got Nagios running on the PC behind your sofa anyway (right?), let’s set up a simple check to scrape the web interface and verify that the ATA is correctly registered with Sipgate:

    define command{
     command_name    check_zoom_ata
     command_line    $USER1$/check_http -a administrator:yourpassword -I $HOSTADDRESS$ -r "Ready to make calls"
     }

    Now define a service using this command, and associate the service with one or more hosts/hostgroups in the usual way.

    The joys of shared houses…

    Being an organised sort of person (and a sucker who can’t say no), I tend to do a lot of the admin and paperwork for the house I share with a few friends. One of the things I do is draw up the chores rota. I’ve typically done it like this*:

    Week      10/09 17/09 24/09 ...
    Bathroom  Tom   David Harry ...
    Kitchen   Dick  Tom   David ...
    Bins      Harry Dick  Tom   ...
    Hoovering David Harry Dick  ...

    Careful and studious readers will have no difficulty in spotting the pattern.

    Inevitably, though, instead of being grateful for the minutes I slaved over my desk putting this together, t’housemates complained. Specifically, Tom complained that ‘I always do something the week after Dick’s supposed to have done it, and he makes a mess of everything’.

    Given the choice between speaking to Dick to correct the problem, or writing some code, I wrote some code which starts with the above layout, then shuffles the columns until the following constraints are satisfied:

    • A given person never does the same thing two weeks running
    • For any given pair of people (p1, p2), this pair never appears twice in a given row

    Careful and studious readers (with Maths or CS degrees) will have no difficulty working out the number of weeks of chores rota I’ve limited myself to doing at a time, becuse the constraints become impossible for a greater number.

    * No, my housemates aren’t really called Tom, Dick and Harry. After five years at an all-boys school, there’s no way I’d live in an all-male household.

    A landline number without a landline: Sipgate Just Works™

    Paying BT or Virgin Media £10-£15 per month for a landline telephone seems like a waste of money when I have a mobile phone contract which gives me 300 free minutes per month. But it still costs more for other people to call me on t’mobile, and not everyone has a contract phone (do they, Mum?). So I’ve been looking around for VOIP providers who could give me a geographic UK phone number which I could take calls on via my home internet connection.

    There are quite a few providers who’ll do this for £3-£4 per month, but sipgate are doing their best to disprove the theory that there’s no such thing as a free lunch, offering UK numbers for free (at least for the moment).

    Within a couple of minutes of signing up, I was the proud owner of a ‘real’ 01865 Oxford phone number and some SIP credentials for registering a device to make/receive calls via it (obviously outbound calls cost real money, it’s just that there’s no line rental or monthly charge to have the number which people can call at their usual geographic rate).

    I managed to set up Linphone as follows:

    Under Linphone > Preferences > Manage SIP Accounts, hit ‘Add’ under ‘Proxy Accounts’, set “SIP Identity” to sip:1234@sipgate.co.uk, “SIP proxy address” to sip:sipgate.co.uk. OK out and you should get a prompt for your sipgate password; put it in and the status bar should read ‘Registration on sip:sipgate.co.uk successful’.

    I’m pleased to report that incoming calls come with the caller ID information – the incoming caller will be “01234 567 890″ <sip:01234567890@sipgate.co.uk>. As far as I can tell, it only supports one incoming call at once, but for £0/month, that’s not too shabby :)

    Next on my list is to buy an ATA and hook up my real cordless phone to sipgate. Watch this space!

     

    Java programmers

    I don’t much care for Simon Willison‘s (or in this case, the person he’s linking to’s) implication that Java programmers are misguided fools in need of help (as opposed to engineers trying to earn a living by using the best tool for the job on hand, rather than getting all evangelical about their language of choice).

    However, the quote he posted recently makes a good point – using immutability and other functional ideas does make for better-written and less error-prone Java. And many of us have moved in that direction already, mostly without any prompting (although since Haskell was the first language they taught me at Oxford, that doubtless influences my world view).

    The internet doesn’t weigh anything, but it took forever to get here

    On Monday 1 August, we moved into our new house.

    On Monday 22 August, we got an internet connection.

    Fortunately, I have a shiny Android phone with WiFi hotspot capability these days, and it turns out the 500MB of data O2 give you lasts almost exactly three weeks if used carefully. They even send you a text when you hit 80% of it, and don’t automatically bill you when you reach 100%.

    All very civilised, which is more than can be said for the process of getting an internet connection in central Oxford. First, we tried to get some ADSL via our BT line. There is a master socket in our lounge (carefully hidden behind a curtain, half way up the wall, natch), but the previous tennants had been on Virgin Media, and the BT socket was dead.

    It took several phone calls to BT and the Post Office to establish that re-activating the line would cost us £130 for an engineer’s visit – even though the wiring and socket looked perfectly intact to me. Oh, and it would take three weeks. The process of arguing with BT Openreach about reactivation is apparently so tedious that the vast majority of ISPs offering ADSL don’t bother, insisting on your line having a phone number and a dial tone before they’ll talk to you (even if you want to pay them for the line rental too).

    Having eschewed the BT monopoly’s attempt to gouge us for £130, we turned to Virgin. More promisingly, their bog-standard 10Mbps broadband (with no phone or TV) didn’t come with an up-front connection fee, but guess what – it would take three weeks to send their bloke to install it. Why they can’t offer self-installation in cases where the house is already wired is beyond me.

    Our connection is currently showing a pretty respectable 9.71Mbps downstream and 0.5Mbps upstream – pretty close to the 10Mbps we’re paying for. The two annoyances so far have been that the engineer was obviously getting a bonus for conserving coax, as they gave us a 60cm length just long enough to put the modem/router on the bottom shelf underneath all our DVDs and books, rather than on the top shelf where it would give a better signal to the top two floors. Luckily some past installation of Virgin had left a lot of coax and splitters in a drawer, so I deployed some of those.

    The other fly in the ointment is that our modem/router is Virgin’s superhub, much maligned by some as flaky and unreliable. I’ve not found the wifi range great on ours, but positioning it on the aforementioned top shelf has helped a lot. The main problem so far has been that, after a brief power blip on Monday, it came back on but disabled the WiFi, leaving me to plug into it with an ethernet cable in order to turn it back on.

    The noddy web interface on the superhub also worried me, but it turned out there’s a well-hidden ‘advanced settings’ link back to the good old Netgear web interface with all the knobs and buttons for the advanced user.

    I’ll report back if we experience any serious problems.

    Meanwhile, here’s hoping that by the next time I move house, some geek will have achieved a landmark victory at the European Court of Human Rights, mandating that internet is a basic human right and must be installed within 48 hours of a person moving in to a new house. Not holding my breath, though.

    http://www.theregister.co.uk/2011/08/25/virgin_media_superhub_update/

    Slow outbound e-mail?

    I’d noticed for years that sending outbound e-mail from Thunderbird to my server on port 587 took far longer than it should have – about six seconds of staring at the progress bar.

    Today, I was finally bored enough to work out the cause: Exim is configured to perform ident checks, which take 5 seconds to time out. Since port 587 only accepts mail from authenticated users, we can disable the ident checks for it:

    rfc1413_hosts = ${if eq{$interface_port}{25}{*}{! $sender_host_address}}

    If you’re running Debian, change the above in /etc/exim4/conf.d/main/02_exim4-config_options.

    Dot everything

    I read with interest the news that ICANN has approved the ability for companies to register .anything domain names (so KFC could register .chicken and have http://chicken as their website). Some are saying that  chaos will follow.

    Personally, I’m not too worried. In the last week I’ve seen both an older relative and someone my own age refusing to believe that websites without www in front of them can possibly exist (visiting www.sub.example.com despite being told to go to sub.example.com), so I suspect anyone silly enough to shell out $185,000+ will watch the abysmal traffic to their website and wish they’d spent their money on a leaflet campaign instead…

    Conspiracy theory of the year

    Over lunch with some colleagues last month, the subject of why Microsoft is paying $8.5bn for Skype came up. “Simple”, I replied, “for years, governments have been looking for back doors into encrypted communication systems, including Skype. The US government must be secretly subsidizing Microsoft’s takeover in return for access to all the Skype traffic”.

    Consensus round the table was that my theory sounded just a bit too plausible for comfort. If I disappear suddenly, you’ll know why…

    IPv6 support in Android

    I’m pleased to report that (having fixed the IPv6 on my home WiFi), my HTC Desire S running Android 2.3 picks up an auto-configured IPv6 address on its WiFi interface. This is then used successfully by the built-in browser, K9 Mail and Irssi Connectbot.

    I was hoping to include a screenshot showing the IPv6 address the phone had obtained, but apparently you can only screenshot a non-rooted Android by using the developer tools … sounds like a job for another day.

    A smartphone named Desire

    After years of thinking about it, and even writing about it, I’ve finally bought myself a smartphone.

    As I write, I’m coming to the end of my third week with my new HTC Desire S. And it hasn’t disappointed.

    Carrying it around has proved less arduous than I imagined – although it weighs more than my clunky old Nokia 1100, it’s thinner and flatter, so it fits nicely in my shirt pocket. It gets quite warm when under heavy use (e.g. acting as a WiFi hotspot), but not unpleasantly so.

    They’ve packed quite a lot into such a small case – in no particular order, we have FM radio, a 5 megapixel camera with LED flash which works quite well for basic snaps, a second front-facing camera for video calling (makes me look awful, but friends insist it’s accurate), GPS, a half-decent speaker, a headphone jack, a nice big touchscreen, and I’m told it also has a phone.

    Typing on the on-screen keyboard has proven easier than I anticipated – even with my fat fingers, I can peck out a short e-mail with reasonable ease. The predictive/corrective text is actually surprisingly helpful here.

    The built-in e-mail client is OK, if a little basic. It wouldn’t send outgoing mail via my Exim 4 server over TLS (a TLS packet with unexpected length was received), but I suspect that’s Debian’s fault for insisting that GNUTLS actually, er, works. I ditched the default client in favour of K9-Mail, which boasts PGP integration and is much more customizable. Apart from a few niggles with the UI, it does the job very well.

    The browser works much as one would expect – even sites without a mobile option are surprisingly usable – the screen is a decent resolution for its size, and the usual gestures for zoom work well.

    The music player worked straight out of the box when I copied some MP3s over, and the supplied headphones aren’t too shabby.

    The ability to read bar codes and search online for the cheapest available version of the barcoded thing has proved endlessly amusing.

    Irssi Connectbot deserves special mention for making IRC on the go dead easy.

    One of the main reasons for opting for an Android phone were the tethering capabilities – with a couple of well-chosen taps, the phone can share its 3G internet connection by turning itself into a WiFi hotspot. This is one of the operations that makes it a bit warm, but it’s very handy if you’ve got a bigger computer with you, but no internet.

    Battery life isn’t too bad given the capabilities of the device – it lasts a heavy day’s usage, and charges over USB from almost anything. They also throw in a standard wall-socket adapter too.

    Android claims some IPv6 support, which I’ll report back on when my home IPv6 is raised from the dead. I’ve also got a few ideas for app development, so watch this space!

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