Telco’s vs. Cable Companies and Service Availability

For the past couple of years, I’ve given highspeed internet with my cable provider (Shaw) a chance. No more. I’m going back to Telus with DSL, even though it is (in theory) less bandwidth. Why? Well, it’s an interesting story comparing the levels of reliability the two types of organizations need to provide.

Shaw is a cable TV company provides reasonably reliable service for TV. In the nearly 20 years I’ve used them, I’ve only had maybe 3 times where there was no TV signal, and that only lasted about an hour in the worst case. But, cable TV isn’t especially hard to do: the cable is sort-of like an antenna. So, basically they have to broadcast a signal over a wire, boosting it from time to time. Your end-user box (TV, PVR, etc) is the one that sorts out the signal for each channel, and there is some amount of error correction built into the signal. The signal can also experience a small amount of loss, but still deliver an accept image and sound. Data networks, however, cannot accept loss of data. Lost data means retransmission for some types of data connections (e.g. for TCP, which is a reliable data stream). Too much lost data means that the communications link can be lost completely, as both sides eventually give up. With data, you can’t “sort of” deliver the data: either it arrives or not. You won’t notice small losses at 30 frames per second (e.g. a couple of pixels are corrupted for 1/30th of a second). Losses in data mean you have to take steps to recover that data.

To get data to your house, the cable TV infrastructure (not being a point-to-point network but a broadcast network) uses a form of Ethernet  known as broadband Ethernet. It was originally meant for use over closed-circuit TV systems in factories and such. That means that you are sharing bandwidth with your neighbours before you even get to a central router of some kind. The bandwidth can be managed, to an extent, via the modem (to give higher-priority customers more access), but in the end, you are using a shared service, and if you live in a technologically savvy neighbourhood, your throughput may not always match the “best” number and will vary.

Beyond that, though, is Shaw’s apparently inability to provide reliable service. In the 2+ years I’ve used them, I have had at least 8 outages. I have experienced 4 this year alone (and we’re not done yet). The shortest outage lasted about 90 minutes. The longest is still underway (it’s been 48 hours and counting). Should I call them? I could, but you know what, I’m not going to bother. When I do, it will be to cancel my high speed service, and just stick with TV.

Instead, I’m going back to Telus and DSL. Telus is a phone company. Phone companies have always had very aggressive uptime targets for their voice services, and that mindset is also apparent in their high speed internet service. Yes, the published bandwidth number is lower. But, in 15 years of using Telus DSL, I’ve only had 2 outages, and both lasted less than 15 minutes. Otherwise, the service has been there when I needed it. The bandwidth has been predictable. Why? Part of that is how DSL works: it is a point-to-point network. It is, in some ways, a “poor man’s leased line”. You get a dedicated line (DSL over your phone line) between Telus’s main network routers and your premises. You don’t start sharing bandwidth until you get into the heart of the Telus network. With cable, you start sharing bandwidth before you’ve left your own neighbourhood.

What I find laughable is that Shaw wants me to trust them to run my home phone. Sorry, but when one provider (Shaw) can only seem to provide 99.58% availability, and the other (Telus) provides 99.9996% availability, guess which one I’m going to trust with my preferred communication with emergency services? You can call me old-fashioned, but until cellular service and cable TV-based Internet approach the availability numbers of plain old telephone service (POTS), I will not use the Internet for my home phone. I want one line in the house that I know will work when the power is out, at that has always, always, always provided me a dial tone for as far back as I can remember.

I’m disappointed when an infrastructure company like Shaw can’t seem to approach a level of availability that is achievable by a telco. I’ve built software systems and its supporting infrastructure, using off-the-shelf computers, routers, and such that provided 99.999% availability, as part of my work building networks at Bell-Northern Research and late with trading systems for stock exchanges around the globe. Yes, there is work involved, but it also isn’t exactly rocket science. I may give Shaw another shot in a couple of years. But right now, I’d rather have a supposedly slower network connection, but one that is predictable and reliable, over one that isn’t. I don’t care how much bandwidth I’m supposed to get on paper. If the network connection is down, that’s a bandwidth of “zero”, and that isn’t useful to me.