For the first time in my life, except for that brief flirtation with ISDN in the late 90s, I'm about to be without an analogue telephone in the house.

From next week, mine will be part of a growing number of Japanese homes whose telephone service comes across a broadband internet connection.

I hadn't planned to cut the cord so soon, but a broadband salesman turned up at my door on Sunday pushing the service. It turns out that NTT (Nippon Telegraph and Telephone) had just put a 1Gbps (gigabits per second) fibre-optic connection into the building and fibre-to-the-home broadband is now available. For ¥4,200 (about £20) per month I can get a 100Mbps internet line into my apartment and, if I don't care about losing my phone number, add telephone service for no charge.

As a result, my total monthly bill will be less than I pay now for 8Mbps ADSL (asymmetric digital subscriber line) service and the telephone. On top of that, my phone calls will be cheaper too.

I felt sorry for the salesman. Temperatures were up around 30º Celsius and the poor guy was wearing a suit, going door-to-door pushing a concept that I expect most of my neighbours didn't understand. So I was leaning toward switching to fibre. I'd been meaning to for a while, but when I found out I'd save money, I was sold on the idea.

I already have a couple of friends with IP telephone connections – it's easy to know because IP phones use the '050' area code. But I was surprised to find just how many people in this country of 127 million people also have that type of connection. The MIC (Ministry of Information and Communications) reported recently that there were 10 million IP phone connections in Japan at the end of March. An additional 1.4 million have a conventional telephone connection over a fibre-optic broadband connection.

That's pretty impressive, as is Japan's growing FTTH (fibre-to-the-home) market. Of the 23.3 million homes that had broadband connections at the end of March, 5.5 million had FTTH connections. That's just under a quarter of all domestic broadband links, and the number is growing fast.

All of this cheap bandwidth is not without its problems for the companies providing it. The country's internet backbone is starting to feel the strain of all these broadband connections. Peak traffic on the major domestic internet exchanges was hitting 158Gbps at the end of last year, according to the MIC. That's about a third higher than the end of 2004 and about double 2003. After all, what are people doing with all this speed but downloading movies, watching online TV and engaging in other data-intensive activities?

The problem is getting so bad that the government is looking into allowing ISPs to charge customers according to the amount of data they send and receive. The change isn't likely soon, but is being mulled over for a midterm IT network plan due to be published in the next few years.

The cheap and cheerful IP phone system isn't quite perfect either. Some network services including emergency calls aren't available from IP phones, but that hardly seems a big deal now that mobile phones are so pervasive.

Almost everything else in my life has already gone digital – the mobile phone, TV, video camera, still camera – so I suppose it shouldn't come as a surprise that wired phones are going the same way. I have high hopes for the service and I certainly can't complain about the internet connection speed or price I'll be paying.