What is the difference between a T1 and DSL?

Can someone tell me, in easy-to-understand language, what the difference is between a T1 and a DSL line and what the advantages of one over the other are?

My company now has a 0-128K burstable T1. We’ve been told that we can get a 384K DSL for 1/6 of the price that we pay for the T1. I do think our T1 is rather expensive but I’ve gotten a couple of quotes from other companies that were only a couple hundred dollars a month cheaper. Plus, we would have to sign a 2-year contract, which we don’t really want to do if we don’t have to. (We are month-to-month on our current T1 [after fulfilling our original contract]).

Would any person in their right mind change from a T1 to a DSL? If DSL is so much cheaper than a T1, why doesn’t everyone change to DSL (assuming it is available in their area)? I understand that a DSL is using copper wire while a T1 uses a fiber optic line and that there is more possibility of disruption on a DSL but does that really happen a lot?

For us, the line would most like be data only, not voice. Anyone have any thoughts? Let me know if you need more info; I’m not sure of what I should be telling people in order to get meaningful answers. Thanks.

I think you have most of the important information. Copper is only going to be more problematic if its running near a source of interference. The other difference may be that fiber is usually run underground and copper is often run through telephone poles, so you might have more outage due to weather.

DSL subscribers are mostly happy in most parts of the country, but it depends on the provider you pick. You will probably not have any more upload capacity than you have with the T1, so if you are hosting a web server or other service that sees significant traffic you might not really see any improvement (look closely at performance claims, they are usually different for upload and download). If you are just downloading files, you will see significant improvement, and for less cost.

Not every provider around here requires a 2 year contract - is that the phone company or the ISP that requires that? The two need not be the same, look into that more. In any case, I think I might go ahead and take the 2 year as long as it had an escape clause if service became unacceptable.

T1 technology is much older than DSL, and really doesn’t win a cost/benefit analysis for most users. The other thing to consider would be cable modem service. I know Cox communications offers business various packages with service level agreements and bandwidth guarantees, that provide far more bandwidth than you’d be getting with your frac T1 (up and down stream) for less cost than the T1. I don’t know if they’ll install the consumer contracts into a business, those are even cheaper than DSL. Cable is often more reliable than phone lines - certainly the shielded coaxial cable is more resistant to typical interference.

Part of what you are paying for with your T1 is the ability to pick up the phone and call a tech like me to discuss traffic patterns, usage history & do real time troubleshooting. I have direct access to the data switch port and can see your traffic in real time along with any errors that might be occurring. I can also see your traffic from point-to-point, that is along the entire length of your connection. So if the trouble is really at the other end of your circuit (you can sedn & receive, but the remote site you’re trying to reach is down), I can tell you that instantly.

DSL is nowhere near that friendly when it comes to repairs. If your DSL goes down, we’ll get around to fixing it in a few days, maybe next week if you’re lucky. If your T1 goes down, we have a committment to bring you back in service within 4 hours. If we miss that, you get $$ back on your bill and you get a service manager working for you. If the repair is dragging, he calls me up and screams in my ear until your service is restored. I doubt if you’d ever get any $ back on your DSL unless you were without service for a whole billing period, and few business can hardly afford to be without fast packet WAN service for a month.

Another service we provide for our wealthy fast packet customers is proactive monitoring of your circuit. If we lose handshake with your router, the switch generates a trap that sets of an a alarm in my center. Some unlucky sap gets to sit in front of a 48" monitor all day long and watch hundreds of alarms scroll by. If your alarm doesn clear within a few minutes, we generate a trouble ticket and call up whoever is listed as primary point of contact in your company for dealing with network troubles. We provide this service 7/24/365. You’ll be thankful for this if it’s 3 o’clock in the morning and you don’t have your own help desk that monitors all your routers. Chances are, we’ll have the T1 back up by the time your business opens that morning. If your DSL goes down, it’s up to you to figure it out & call us. Be sure to have something to read when you call the DSL center, cuz you’ll be in queue for an hour after which somebody will answer and place you on hold.

Have you asked about increasing your burst rate? I think it’ll only be a few dollars more and from what you’ve said you already have a full physical T1, which is restricted to a virtual 256k (that’s 128k with a burst of 128k).

T1 circuits also have loopable devices at various points, which is a huge benifit when it comes time to shoot troubles. You probably have a loopable T1 card called a smart jack at your site. From the switch, I can send out a loop code that will help me prove the T1 portion of the circuit good. The customer equipment (channel service unit & router) may even be loopable from the switch, so I might even be able to test your equipment for you if you’ve enabled those options.

In terms of quality of service, T1 is full duplex at (up to) 1.544 Mbps, while DSL speed and quality depends on the length of the loop and condition of the pairs. Got flaky pairs? Gee tha’s too bad. You’ll only get 240k download and 76k upload (or whatever), and that’s not considered a trouble condition, it’s just what you can get based on the prevailing conditions. On the other hand, if you’re paying for a full or even fractional T1 and your LAN tech sees errors in the data or slow throughput, that’s a legitimate complaint and it’ll be up to us to bring you back up to full speed pronto.

T1 also allows you to connect all of your various locations by adding virtual channels to your existing T1. This would be usful if you happen to have one major location and multiple remote sites, like a bank. Many business would be a little wary about sending sensitive data from site to site via the internet, and would prefer to have a private line that exists only within the fast packet cloud in the switching network.

I would add that you will pretty much want to use the Bell provider in your area for DSL. Unfortunately, my experience with Bell and ISDN (yes, I know that they are different) is that Bell is generally clueless and helpless for anything outside of regular analog service.

On the downside, that means that any problems you have, you are going to have to figure out how to fix on your own.

On the upside, at least with the ISDN, when I finally got it working, I never had troubles with it.

Yes, you could use one of the competitive providers, and from what I’ve heard, you will get great customer service. The only real downside with them is that they will cost slightly more than the Bells (although still a LOT cheaper than a T1) and most of them have been declaring chapter 11 recently.

Either way, don’t disconnect the T1 line until you have the DSL up and going for at least a month. I’ve heard enough horror stories about appointments getting moved around and also about problems after the initial hookup that a month would be the minimum amount of overlap time that I would want.

By the way, if you haven’t checked it out yet, you may want to visit http://www.dslreports.com

t1 can be over copper - usually 2 pairs. If dsl goes down you can get a refund on a daily basis (must be out for 24 hrs - and totally out if you are getting 0.1kb/s it’s not technically out for refund purposes)

Here is the really big difference between the two.

Burstable T-1 allow a full 1.5 mbps upstream and downstream. They just bill you on you average usage. Burstable T-1’s are not throttled at all.

A 384k DSL has a maximum throughput of 384kbps.

T-1 typically has much lower latency than DSL.

T-1 packages are typically much more generous about handing out larger number of real static IP’s.

And as Attrayant pointed out, T-1 generally have REAL support.

And just to reiterate, most DSL or cable companies don’t make much in the way of guarantees for throughput. You may find yourself throttled back unexpectedly during busy times. And my cable connection routinely goes offline for a minute or two here or there as they switch me to different routers, or swap out hardware, or whatever. I just keep trying until the connection comes back. For a home user, no big deal. But if your net connection is mission critical, even a short outage can be devastating.

Also, you’d better read the DSL contract carefully. Many of them have riders which allow them to charge you extra if you go over a certain number of megabytes per month of traffic. I’ve heard horror stories of people setting up web sites on their DSL line and then getting their URL published on a big site or on TV or something, and suddenly getting flooded with so much traffic that the cable company gives them a bill for a couple of thousand bucks at the end of the month.

And many DSL and Cable providers will not allow you to host servers on your DSL line. The reason DSL is so cheap is because the companies can generally assume that the average person will only use a tiny fraction of the bandwidth available to them in a given month, so they can multiplex a lot of people onto the same trunk. But if you set up some high-powered server and start pumping data full time 24/7, your provider may have something to say about it.

Many DSL companies won’t allow you to make VPN connections to your office, for the same reason.

most can’t stop you

cable - no, dsl - yes, Opal - Hi. You just have to get a more expensive dsl package.

Working with various computer and telecom issues has taught me at least on thing: go T1.

T1’s can be delivered via regular copper, although T-1 is now usually delivered on fiber optic transmission systems.

DSL typically operates on one pair of wires, like a normal analog phone line.
And, haven’t DSL services been falling like flies? Service is evaporating to cut costs.

T1’s are “industrial strength”. T-1’s are not “lines”, in as much as they are configurations.

You may also want to investigate if you can get a cable modem connection.

If you can, you should consider getting both DSL and the cable modem. The likelihood of them both being down at the same time is rather small. Even after getting both, you will still be saving hundreds over the T1.

I think what it comes down to is how important is your internet connection. If you are hosting a website and you absolutely can’t go down, you might want to look at having 2 T1 lines (to different companies). If you just need a way for employees to occassionally access the internet, you might be able to get away with sharing an AOL account. And, there’s a whole lot of room in between those two extremes.

Since you have only a 0-128K burstable T1, I’m going to assume that you aren’t hosting a website and that this connection is mainly for outgoing use. Personally, I think a combo of DSL and cable modem would be perfect for you. If you can’t get the cable modem, I would go for DSL and have a good overlap period while you work out the kinks of DSL.

Also, about the 2-year minimum contract. Usually, a contract like that gets you free hardware. Check to see if you can buy the hardware and then go with a month-to-month contract. If not, look at the bright side, in about 4 months the T1 would have cost more than 2 years worth of DSL.

Thanks everyone. I just don’t know what to do - I really hate having to deal with this kind of stuff because I don’t know anything about it and can’t tell what is the truth and what is the salesperson’s bull. Part of me just wants to stick with the T1 because at least that is already set up and working and if we were to switch to DSL and it sucked, I would be the office idiot.

What got us looking at DSL in the first place was the price difference. We are paying about $1,600 a month for our T1 through UUNEt and that seems really expensive to me. I have gotten a quote from AT&T that was only a couple hundred bucks a month cheaper but would require a 2-year contract. I can get UUNet to lower our rates to about $1,200 a month with a 1-year contract but that still seems so expensive. Are those normal prices? I think we probably could get a T1 for cheaper with an “unproven” company but we are very wary of going with a provider that goes belly up in a few months. Does anyone know how I could generally compare prices without having to get a bunch of salespeople in here? They just take up so much time and then never stop calling me.

Well, thanks again. I am continually amazed at the level of knowledge here! :slight_smile:

Saw bpaulsens’ post on preview: we do have a Web site but it’s just a few basic pages; but we do use the Internet heavily. We also host our e-mail here on an Exchange server; I guess our mail (which is very heavy) must go over the T1 also (?).

The T1 rates that you are being quoted are a bit high, but not excessively. T1 just costs a ton of money, and as others have suggested, most of that money is for service. I.e., if the service goes down, you’ll have someone working with you to get it back up and running.

Now for the reality checks. We’ve had troubles at my office (a BIG financial firm) with some of our T1 providers. I’ve found that when we’ve had troubles, we had to point it out to the provider (UUnet was one of our providers, although I don’t recall if we had troubles with them) and more or less prove that the problem was on their end. The bottom line is, if the connection goes down, you will still need a good technical person at your company to help fix the problem. With that said, if you have a T1, once you can prove the problem is on the provider’s side, they will generally get it remedied very quickly.

I was running a small website at my home that forwarded email to people’s cellphones and pagers. As such, I tended to get lots of email (small ones, though) and I found that my cable modem could easily handle most email. Of course, I was lucky in that my provider can deliver 5Mbps download and 1Mbps upload.

If you haven’t checked it out yet, I would highly recommend perusing http://www.dslreports.com. You can put in your ZIP code and get a list of companies that can deliver DSL and cable services in your area. Furthermore, you can go to http://www.dslreports.com/prequal and get the list of DSL providers and find out how fast of a connection each can offer. Also, you can see comments about each company so you can get an idea about what level of support and reliability you should expect.

If you go with DSL, I would be VERY hesitant to go with a non-Bell company. Most of them are going bankrupt, and if your provider was to go under, you could find yourself without an internet connection for anywhere from a few weeks to a few months.

The other thing you may want to check out is what is the maximum speed you can get with DSL. Depending how close you are to the CO (central office) you may be able to get speeds of up to 7.5 Mbps with DSL. The farther you are from the CO, the slower the speed. If your top speed is limited to 384Kbps, that may be a big strike against DSL. The probability of a new CO being built by you in the near future is very small.

Also, what’s the office size and is it expanding? An office of about 10 people may do fine with a 384 Kbps connection. Anything bigger and you will probably want something faster.

Finally, if you have a few static web pages, you might do better to have an outside company host it and let them worry about bandwidth problems.

My ISP has T1 & DSL, here is what they say about T1:
Red Shift now offers full T1 speeds at the excellent monthly price of $699.95:

* Includes internet access fee
* Includes all telco charges
* 1500k upload
* 1500k download
* $0 setup fee until August 31st!
* Up to 32 IP addresses
* No distance limitations

This product requires a router and CSU to terminate on the customers end. You may obtain your own or purchase one through Red Shift.

Frankly, I would rather have a satellite modem. As a matter of fact, my ISP has a few dishes on their roof.

As you may have realized from my above lengthy post, I work strictly in service, so I was not aware what we charge for data services. After poking around on my company’s web site I have come up with the following rates for Frame Relay service:

Frame Relay UNI port & access line, each

**56Kbps**           Non-recurring charge     Monthly Rate
Month to month   $195.00                  $110.00
One year         $195.00                  $105.00
Three years      $195.00                   $95.00
Five years       $195.00                   $85.00

Month to month   $395.00                  $380.00
One year         $395.00                  $370.00
Three years      $395.00                  $355.00
Five years       $395.00                  $340.00

Month to month   $395.00                  $530.00
One year         $395.00                  $510.00
Three years      $395.00                  $490.00
Five years       $395.00                  $470.00

If your PC can handle enormous PDF files, I believe you can look through the entire tarrif schedule here:


Click on “Tarrifs” at the left, and then select your state. Keep clicking on links that say “tarrifs” and eventually you will get to a list of links, one of which should be “description of data services & rates”. That’s where I got the above info.

There’s also a lot of general info there about data transfer via various protocols like Frame Relay, ATM and TLS.

So far some very good details on DSL vs. T1’s have been given but one HUGE question needs to be answered before anyone can suggest which is the right option for you.

What do you use your internet connection for?

Unfortunately the answer to that question can be quite involved. Is it just for e-mail? Do you tend to have large attachments in your e-mail? Do you have your own e-mail server or is it hosted elsewhere? Do you host your own webserver? Do you conduct business transactions via the internet? How long can you afford to be without a connection? How many people use the internet connection (for business…not checking the latest sports scores)? Do you need features such as streaming audio and/or video? Do you run a VPN in your office? How fast is your current T1 (fractional or full T1)? What QoS agreements do you have with your service provider? Who owns the router equipment in your office? Who is responsible for managing your equipment? etc., etc., etc…

There is no one ‘right’ answer in T1 vs. DSL. There is only a right answer for you and your business.

A T1 line is almost always FAR more expensive than a DSL connection. What you are paying for is a QoS level that you rarely get with a DSL line (DSL can sometimes be faster than a T1). That’s ok since it really depends on what type of service you need. It’s nice having guarantees out the wazoo but why pay for a semi if all you need is a pickup?

You T1 price seems a little high but that varies reagonally. I like to see it around $1k.

Also I know of no cable internet service for business - I could be wrong buyt never heard of it and if the cable co’s find out you are running a business they get really pissed. Cablevision Lightpath is a phone co that does offer internet service but that is a t1- dsl thign not cable tv.

Hey here’s a thought - get dsl try it out but keep your T1 for backup. run a few months off the dsl if no prob - consider getting rid of it. If any trouble drop dsl. the cost of dsl compared to the t1 should make this cost effective. and get your phone co’s dsl this way you are dealing w/ the co that can actually fix problems.

Our Libraries use T1’s.

And those are your tax dollars hard at work. I’m going to bet Missbunny’s company doesn’t get state government funding for her fast packet data services.

Missbunny - check your e-mail…I might be able to help you.

Yeah, but our libraries are all linked together.

How about a T3? Im not up to how many T’s there are but I bet there is more than one.