But this is yesterday’s news. We all have caller IDs. It just works. Well, yes. It does. But what if we get a call on our landline? We get the caller ID there too, but do we know who it is?? All our contacts are on our mobile phones. Standard phones don’t usually have the capacity to hold more than 10 names on average. And even if they did. Who’s got the energy to key in those numbers?

Enters Asterisk. Asterisk supports name as well as numbers for caller ID. But how do you get your asterisk to know the name of the caller? How can we inject the caller’s name into the caller ID string sent to our voip phones?

I’ve seen some online posts (like this one) about setting up look-up through online phone directories. I wanted something simpler. Why can’t I have my asterisk know who’s calling, based on my contacts on my iphone address book??

So here’s what I did. It can work on any address book format, as long as you can get it out as a csv (examples for iphone here and here). I created a simple CSV file, with two columns: Name and Number, which looks like this:

I then created a little python script to run on my asterisk box, and pull the name based on the number. It’s an AGI script, but it’s so basic it doesn’t actually need any AGI libraries:

It can be invoked in the same way as described here, i.e.:

Note that it’s currently only working with full matches. The caller ID number must match the record on the address book precisely. Let me know if you have any simple ideas for partial matches (e.g. to avoid non matches of numbers, e.g. +447771110006 != 07771110006). I’ll do some more research when I get a chance.

Update: code now deals with partial matches rather effectively.

Another benefit is with voicemails. I started forwarding my voicemail straight to my asterisk box. My mobile provider doesn’t support visual voicemail yet, and I find it frustrating to use the old fashioned voicemail system. Now when I get an email with the voicemail message, I not only see the number of the caller, and can call them back with a click. I also see their name.

ISPs enjoy a legal freedom of being considered a mere conduit. That means they’re not responsible for whatever their customers do with their connection. Nobody can sue the ISP for copyright infringement or any such or other illegal activity. And it makes sense. They’re just a pipe. If you, as a customer, choose to send poison down the pipe – it’s not the ISPs fault. That is, as long as they don’t control or take part in the communication.

Some ISPs want to have it both ways however. They’re not happy with some of the traffic, want to reduce their bandwidth and costs, and so they start using some traffic shaping measures. Their customers aren’t supposed to notice, and they are rarely being told about it either.

Whilst in Israel, I encountered a weird problem with 012 Smile, a local ISP. I must have spent hours on the phone to their support until the issues I was having were resolved. Some sites were painfully slow. Watching a youtube video or any video on the BBC, Guardian and many other websites, particularly out of Israel, was simply impossible. The other odd thing I came across was that one TCP port seemed to be blocked completely. One of my hosting providers use port 2095 for webmail. I simply couldn’t establish a connection. Testing it further, I noticed that the connection on port 2095 was established, but I was getting no response. As if there was some transparent proxy along the way. This whole thing reeked of traffic shaping, or worse, active blocking of services. Convincing the support staff it was an actual problem was no easy feat. I’m lucky I know enough to explain and insist when necessary, but for the average joe (or average Yossi in this case), 012 makes it next to impossible to get it sorted. Their support blamed it on the computer, on the router, on the cable provider. They blamed it on anything but themselves (oddly, they didn’t blame it on the boogie!).

So the problem got sorted out eventually. It was painful, but 012 made some magic changes and things got better. I insisted on getting a full explanation about the problem, but was given none. All they said was they fixed it. They claimed to made some routing changes, but no routing changes can affect access to a single port!! Pushing the support staff further, I was hinted about some traffic shaping that 012 are using.

How can you tell your ISP is using traffic shaping? Shouldn’t it be something they HAVE to tell you about? I think it should be. This is not something you see on their website, or even T&Cs. I personally think legislation is the way forward here. And of course consumer pressure. Most consumers are sadly unaware of it.

I’m not sure if or how much traffic shaping is done in the UK. However, UK ISPs are reported to show concern about the new Digital Economy Bill. Particularly the need to monitor their own users and track repeat offenders. Without going into debate into the bill itself (for which there is plenty of criticism), those ISPs who use traffic shaping and blocking might find it hard to argue their case. If you do control traffic in some way, you’re no longer mere conduit, and you CAN be expected by the government to enforce other degrees of control (and responsibility/liability) over your users.

Anyway, enough about me.

cron cron cron, the mighty scheduler. Making sure things are running on time, but does it? Well, sort of. My cron (or more precisely anacron) has failed me. It appears like a logrotate cron.daily job was stuck due to some random bug in the lighttpd postrotate script (see here). Causing anacron to lock, giving messages like:

I don’t get it why if one script in the /etc/cron.* directory fails, or hangs, anacron doesn’t somehow detect it and moves on. I tried searching a bit, but couldn’t find anything. Any ideas or suggestions are welcome.

I then decided to be a little more careful, and monitor those cron jobs myself. The most important jobs are those running rsnapshot to run regular backups. I was looking for a simple way to check a file/folder modified timestamp and alert me if it reaches certain threshold, i.e. it’s older than X days.

I am already using munin, for monitoring cpu, network, diskspace etc and it has a CRITICAL/WARNING email notification built-in, so I thought it might be a good tool to use for this purpose too. The graphs aren’t going to be particularly useful, but the alerting functionality is.

It’s my first munin plugin, and one of a few python scripts I’ve written, so hope you can be forgiving for lack of style or technique