What is better for trading from home cable modem or DSL? Can either one of these compete with T-1 lines?
They can sure compete on cost. In fact, they blow T-1 out of the water costwise. You might pay for that in other ways, though. Cable gets the job done for me most days. I can't say that cable has adversely affected my trading since I left the office and its T-1. I know that purists will disagree. If I thought it was essential I'd T-1 in a hurry. And, if I were paying for a T-1, I'd probably have made up my mind that cable was lacking. You probably can't really scallop without a T-1.
Another alternative is to use both. Cable or DSL both go for around $50/month here. I'm considering getting both for redundancy and routing purposes, and getting a router that load-balances between them (and as a consequence, handles failures transparently). The router I'm looking, nexland 800 (review here http://www.overclockersclub.com/nexland.shtml), should be fairly easy for anyone with experience with the most popular router/firewall device out there, the Linksys BEFSR41. Using this load-balancer, I should be able to get upwards of 3 Mbs by combining the two...pretty cool. *And* have multiple routes since my cable ISP and my dsl ISP use completely different backbones. Sometimes there's fewer hops to a server on one vs the other. But more specific to your question, cable and dsl are fairly identical to most users. What really matters in my book is the backbone that the provider is connected to and how great their customer service and technicians are in keeping the network up. I've been using AT&T here in Seattle for over a year now, and have had no failures and decent performance. Despite my personal tendency to expect poor quality from mass-market providers of anything, I have to say that everyone I know who's had them has been fairly happy, including myself. For now. This is in stark contrast to Qwest DSL, about whom I have heard numerous negative stories. When I finish my upcoming move, I'm likely going to get (er, add) dsl through a smaller, local company I like, with better backbone connections and more liberal bandwidth/server policies. I wish that router had a back-up dial-up port. Can't go wrong with three backups, right?
T-1 is around $500. DSL/Cable is about $30 or so. For your purposes, T-1 is probably not worth it. It is more for networks, like a company (small or large) that has numerous computers working at once.
I use both, and it comes in handy when one is having trouble. I have yet to have them both go down at once (knock on wood). As far as which is better, I think it totally depends on the local company. Changes in my provider have had more impact on the reliability of my service than whether it was DSL or cable. I think I would rather have cable and DSL together than a T1 alone for the type of trading I do (T1's can go down too I assume). However, I have never actually used T1. Good luck.
Plus applicable long distance fees, correct? *** Corvus, interesting idea for a backup. I'm getting ready to backup with DSL or an alternative cable carrier as well. I didn't know this little gizmo was out there. Also, two of them in series ought to solve your problem (if you absolutely had to have three backups. When things get that bad, I call the order desk with my cell).
another thing...T-1 is the most reliable single choice, supposedly. T-1's have been around since 1957, so it's old technology, and the connection between you and the ISP is basically all yours. There are no distance issues (quality of a DSL connection decreases by distance from the CO) and the connection is basically a big, reserved pipe (the equivalent of 24 active voice channels) between your house/office and the CO (and the ISP's routers, in the CO). Also, you get 1.5 mbps up *and* down (most DSL connections are 1.5 Mbps down and 128 Kbps up). That being said, every company I've worked for that had a single, primary T-1 has had it go down at least once a year, and every place I've worked for had DSL as a backup. So, nothing beats redundancy for protection from problems, which is why I'm going to go with cable and DSL paired. I'm not particularly keen on the "tried-and-true technology" argument for reliability, especially given the cost differential. Cost of a 1.5/1.5 Mbps T-1: $750/month + $800 install and hw. Cost of a 3/.5 Mpbs cable & dsl pair: $140/month + $40 install.
I don't actually have them connected. I use two machines with all software loaded on both. I use one for quotes and charts, the other for trading platform. If I loose one connection, I fire up the software on the other machine. I loose a few seconds, but at least I can keep trading. Your idea of using them simultaneously is really interesting. I would be interested in doing that myself. I hope you keep us posted on how it works.