Month: September 2014

Asterisk back talking to the Strowger again

It seems that when I was fixing Shellshock the other day, I managed to get the server into a state where it didn’t know it had a card in it which can talk to the Strowger, so dialling in/out of the asterisk over the junctions to the UAX failed.

I’ve now fixed this!

Click “Continue Reading” to see lots of boring linux related technical details of the problem/fix.

Continue reading


“Shellshock” has been reported in the news a lot over the last day or so (eg and you might be forgiven for thinking the sky was falling in!

This is just a quick post to say that we weren’t particularly exposed to this security vulnerability in the first place (we were running a vulnerable version of the software concerned, but remotely exploiting that vulnerability in out setup is – at worst – extremely difficult!)

However, this evening I’ve made sure we’re all patched and up to date. Nice and tidy.

Dean Forest Railway – now on CNet!

CNet is a network of heritage telephone exchanges around the world, connected together over the internet.

We’ve recently joined, and if you’ve got a DFR VoIP phone at home, you can now make calls to CNet numbers around the world! For directory listings of numbers you can try calling, see

Incoming calls from others on CNet to DFR VoIP services are possible, although at the moment I’m planning on making this opt-in.

So if you’d like CNet members to be able to call you, drop me (Paul) an email and I’ll assign you an inbound CNet number. If you’d like it to only work at certain times of day (eg 10am-9pm) that is possible as well.

We’ll be making a small set of facilities available to external CNet callers, and we’ve started with the speaking clock – which is now available on CNet +44 (0)594 48081

It’s only been available for 12 hours or so, and has already been called 16 times by 10 people on 3 continents!

DDNS tracking reliability confirmed

I’ve just been looking at the monitoring for our dynamic dns and it looks like the new update script is tracking our IP changes reasonably well.


The top graph shows the state of our DNS entries. When the line is “high” it means everything is working fine, when the line is “low” it means that our DNS name doesn’t resolve to the right IP address because our IP has changed and the DNS hasn’t caught up yet.

The bottom graph shows how many IP addresses the monitoring has seen per-hour. On a healthy broadband connection, that line should be fairly flat. However, the broadband at Norchard is so flaky that the router drops sync several times a day – getting a new IP address in the process.

So you can see, on the left hand side of the red line – we were frequently losing sync with our DDNS provider with the old script in place. With the new script in place we were out of sync for a 1 minute period yesterday, despite experiencing 7 changes of IP address!

Why is the broadband so flaky? As it gets worse in damp or cold weather, I suspect an earth leakage on one leg of the line caused by a damp joint, or a nick in the cable somewhere between Norchard and the exchange.

However I’ve always been told the Norchard broadband isn’t our responsibility – so I’m not best placed to get that looked into.

The “powers that be” seem hell bent on moving away from BT Broadband to Chess (and if I try and get the BT broadband fixed, they’ll moot that as a “cure”) – although that’s not going to improve matters if it’s the line plant which is at fault.

Which I’m fairly certain it is.

Directory Updated

The (members only) directory page has been updated to include the number for the new cafe building.

Talking of the members only pages, due to a performance issue with the previous way of handling members-only pages, I’ve switched plugins (from “User Access Manager” to “Restrict Content” if you’re interested) and the new one performs much better, so pages shouldn’t be painfully slow to load any more.

However, if you’re not logged in the new plugin doesn’t display a friendly message asking you to log in – it just gives you a page title and no content.

When I get a moment I’ll see if I can prod at the code until it does something more friendly, and then submit a patch back to the plugin maintainer.

A more robust Dynamic DNS client

For a while now, we’ve been using a lightweight dynamic dns update client which I found on the web somewhere.

It was reasonable, but it doesn’t always play nicely with the BT Broadband router. If it attempted to make an update while the router is rebooting, the BT Broadband router returns an error page, which made the script think it had saved it’s IP correctly.

The practical upshot is that sometimes our IP address would be out of sync until the router had rebooted 2 or 3 times. Luckily for us (?) the Norchard Broadband is so flaky that it frequently reboots 3 or 4 times within an hour.

Anyway. I’ve ripped the script apart and rewritten it from the ground up to be more flexible. I’ve beefed up the logging, and now if it encounters a temporary error it does nothing until the next time it runs (a minute later) – when it should sort itself out.

If you’re interested, you can grab it from here