Telephones

An Eccentric Anomaly: Ed Davies's Blog

I don't much like telephones. They're great for “operational” use for updating when you're already expecting visitors, deliveries or whatever. They're also great for chatting (particularly with video), again when you're expecting a call because you've just escalated from chatting on a text medium or whatever.

What I don't like are calls (incoming or outgoing) when you're not expecting things and are put on the spot to make decisions. And they're totally infuriating for transferring data (e.g., giving an address or directions). And the lack of a record is a serious impediment (though I suspect some people see that as a plus, but maybe they have better memory than me).

I don't hate telephones as much as James Fisher does but I can definitely recognise where he's coming from.

So, it's a bit surprising how many telephone numbers I have.

I have a cheap Android phone which has a mobile number, of course.

Separately, I have a little MiFi pebble for mobile data when I'm out and about. I don't use it a lot but it's sometimes handy to be able to look at the rain radar when I'm on my house site. It needs to be used every six months to keep it active. It has a number though it's not much use; I think you can send text messages to it but that's pretty pointless.

I keep the MiFi going rather than use the data on my phone, which does tethering just fine, mostly for redundancy and also because you can put the MiFi somewhere it can get a better mobile signal then talk to it via Wi-Fi from somewhere comfortable.

Then I have a landline in the house I'm renting. It's a copper pair to the exchange (actually, to the fibre cabinet just outside the exchange but that's a different, and slightly painful, story). Unlike most such lines it's not actually a telephone line as such - it's a “wires-only” service providing only an internet connection via my ISP. It has a telephone number for Openreach's reference (e.g, for when the next tenant here wants to take it over) but you can't call to or from it.

Actually, there is a voice on the line. It's a repeated recorded announcement designed primarily to ensure that Openreach engineers don't borrow the pair thinking it's unused because they can't hear a dial tone on it.

When I moved into this house I wasn't sure if just having a mobile phone would be sufficient. The signal is so spotty around here and the walls of the house are so thick that it turned out not to be really practical. Anyway, having to carry your mobile phone around at home is a bit of a pain: e.g., this post delivery cock up. It wasn't so much of a problem in the mobile home I was in before because reception there was a bit better and it wasn't really possible to get out of earshot of the phone even if I wanted to.

As a result I decided to get a Voice over IP connection. This works by a provider (Sipgate in my case) having a system which acts as a gateway between the public switched telephone network and internet connections to their user's computers and phones.

Skype is a similar sort of VoIP service except that it seems to act as a front for the US intelligence services and uses proprietary protocols which don't play well with other networks and whose security is not up for public review. Consequently, I don't use Skype any more. Its more recent neglect of the Linux client knocks on the head any possibility of my going back.

The Sipgate account is free and incoming calls are free to me and charged as normal national-rate calls to the caller. Sipgate get a termination fee from the caller's carrier, I assume. You need to put some credit on the Sipgate account for outgoing calls which are charged at a reasonable rate though without all the usual BT “friends & family” and weekend calls discounts.

You can have any area code you like. I chose to have the local one covering both where I'm renting at the moment and where I'm building just to avoid having to explain things when I give local people my number. Still, I can make and answer calls anywhere that has an internet connection with more bandwidth than a bit of wet string.

On my laptop I run Linphone to make and, potentially, receive calls. One advantage is that I can use a headset allowing use of both ears which helps quite a lot as I'm slightly deaf in my left ear but quite right handed. Actually, apart from testing with my mobile phone, I haven't received a call using it yet mainly because the headset's not normally plugged in and it's too much to scrabble around to plug it in while the phone's ringing.

I'm using the version of Linphone (3.6.1) that's in the Ubuntu (18.04.1 LTS) repositories which is, unfortunately, a bit out of date. There's a Linphone 4 which looks like it's had a major GUI facelift though I don't know how much the functionality has changed.

For incoming calls or if the computer's turned off I have an analog telephone adaptor (ATA). This is a little box which has an ethernet connection which plugs into my router and a telephone socket into which I plug a normal BT cordless-phone base station. Here's a little row of most of my “always on” kit:

ZyXEL ADSL router, Grandstream HT802 ATA, cordless phone, Raspberry Pi doing data logging. Not my wallpaper.

There's another cordless phone upstairs on the bedside table.

The phone base station has an answering machine facility but I usually leave it turned off as Sipgate send me an email for missed calls which I'm much more likely to notice.

Making and receiving calls on the phones is just the same as if the base station was plugged in to a normal BT line. You can also do funny tricks using asterisks to make free calls across the Internet to other SIP phones including ones on other providers (but not Skype).

Of course, to make such calls it would normally be better to use software like Linphone on the computer, not least because that would allow video calls as well. End points are addressed using sip: URLs (like http: URLs; I think there are also sips: URLs for secure connections but haven't looked into that yet). E.g., users on Sipgate have addresses like sip:1234567e0@sipgate.co.uk (the “e0” bit is optional and nope, not putting my real address here though some people do).

You don't need a provider giving connections to the public switched telephone network to make and receive free internet SIP calls. Typically, though, you do need some sort of service provider to help set up the connection because of problems with addressing and NAT.

Because Sipgate's main focus is on gatewaying to the PSTN and because the address they provide is so closely associated with my telephone number I have a separate account (on Ekiga.net, also free) which is a bit more “disposible” so can be given out with somewhat less worry. It seems to work fine with Linphone but, ironically, I couldn't get Ekiga's own software to work with it nor the ATA (mine actually has two lines). If anybody wants to play drop me an email.

Portability like this is an advantage to self-builders like me. I anticipate a transition period when I might be wanting to answer landline calls in the almost-complete house during the day but in the rented house in the evening. And when I finally move there'll be no need to deal with BT to get the number moved.

You can make emergency calls (112 or 999) from a VoIP phone if you pre-register the associated address with the SIP provider. I have mine set to the house I'm renting and any emergency calls from Perihelion would have to be on my mobile phone; there's pretty good reception there though incoming calls sometimes go adrift for some mysterious reason. When I move I'll need to update that address.

A disadvantage, though, is that the landline doesn't work in a power cut. A UPS might be nice but I haven't bothered yet though I know a few people (JSHarris, skyewright and DamonHD) who've set up some sort of battery system to run networking kit like this for at least a while without mains but I hope to have a big battery for that in the not too distant future. A couple of years ago there was a 36 hour power cut here but since then the longest has been about 2 hours. If desperate I could go to the house site and get my generator or inverter and stick a mains lead through the window though the most common cause of power cuts here is the combination of heavy snow and high wind which would make access to the house site tricky.