T1 Vs xdsl

1. T-1's are 1.536Mbps both ways(full-duplex), full time
2. 1.536 speed is guaranteed full time
3. T-1's typically can be accessed by remote test centers for faster trouble resolution
4. Uptime can be "guaranteed" by "Service Level Agreements"
5. T-1 is traditionally a business-grade service, not consumer-grade

That being said, when I was managing networks, I had T1s go down on an almost weekly basis. My consumer class DSL from Bellsouth has gone down a total of three times in over 4 years at two different houses.

Jim

John wrote: : Hi, : I am just wondering why would any go for T1 lines since it so expensive : compare to xdsl. Consider distance is not an issue.

We sell Internet connectivity over T1s and DSL. Both methods of transport are products leased from the local LEC. So, the telco sells a pipe (DSL or T1) and we well the connection to the Internet.

DSL in this case means 'DMT signaling with interleve on.'

T1 means 'T1 signalling delivered to the customer.' Often, it is delivered to the site via HDSL, and then converted to T1 signalling.

T1s have certain characteristics inherent in the way they are delivered and sold that *may* make the worth the extra money: - lower latency (4 - 8 ms vs. 30 - 50 ms) - faster repair time (4 hour response vs. next day) - dedicated bandwidth for the customer

We also afford out T1 customers quite a bit more direct service. Things like: - direct access to second level techs instead of first level - no charge for routing blocks of address to the end-user site (yes, we *will* do this for DSL customers, but they pay additional fees) - no charge for hosting DNS services - we interface with the Telco that provides the T1 rather than the customer having to deal with the issue - we will do some minimal consulting to ensure that a T1 customer will be able to integrate their network with ours with minimum hassle. DSL customers are on their own.

The big decision pieces in my mind come down to: - how much support am I going to need from my ISP? - how much does downtime effect me?

In general, DSL is for people that can answer 'little' to both questions -- this typically means the consumer crowd, but some businesses also fall in this category.

As always, YMMV.

Also my SDSL lines are 1.5 both ways (full duplex, guaranteed full time. And I also have some T1's for pt to pt service between buildings - they fail MUCH more often than the dsl lines.

That's total baloney. There is no per user limitation. As long as the total bandwidth used by the users does not exceed the bandwidth of the dsl line, you can have as many as you want. I have about 200 on 1 dsl line.

It depends on what they do and what quality of service they expect. One p2p user could hog the full line. If it's just email, you could probably handle many more. Web use is in-between.

-- Robert

Speakeasy sells routed 1.5 SDSL for somewhere just under $300 last I looked, and that includes 32 IPs, DNS hosting, etc.

They also sell (bridged) 6.0m/768k ADSL for $110 with 4 static IPs.

Makes T1 a tough sell, especially when you're done adding all the extra costs, taxes, costlier CPE, etc.

Then again, Speakeasy is now selling T1's starting at $300, add a few bucks if you want hosting services.

The prices are dwindling!

The differences: 80% vs 100% throughput guarantee, and SDSL isn't really 100% full-duplex so if you have a fairly constant data stream in both directions, you will notice a loss in performance, and (here's an interesting one) their response time is now 24 hours for SDSL and 4 hours for T1. Funny part is, I seem to recall that before Speakeasy was selling T1 they were offering 4 hour response on SDSL!!! Bastards...

Watch those taxes!!! The gubmint grabs a particularly large chunk on anything deemed a business grade connection. If cash flow were a huge issue, that hot ADSL seems awfully attractive.

Rev. Brad

My SDSL is < 5 (usualy about 3 ms) to my first hop. Dunno where he got that crazy 30-50 figure.

Are they really not full duplex or did they just perform worse is a test with TCP?

Andy.

Do all SDSL lines in the US have 30-50?.

I read SDSL is better than ADSL for latency and discounting bitrate my DSL is

My adsl's local loop rtt is about 6 ms. My sdsl's is about double that, but that's because interleaved data in on there. Back when it was Savvis (now Alternet) it too was about 6 ms with no interleave...

Some stuff is even slower, like Sprint's ION service which was about twice as high.

Billy Y..

I have the same thing from DSL Extreme for about half the price (total amount due per month: US$62.16) and with no term commitment, it can be canceled any time with no penality at all. Which is good cause prices seem to still be dropping, heh.....

Billy Y..

You just described me. :-)

I know have been paying WAY too much for my T1 compared to what hear about DSL/SDSL offerings. Probably, no, I'm sure half the cost is in tariffs and taxes which sucks!

But when that T1r goes down, I don't want to hear about a fix in 24-72 hours! I get a pager/email notification when it does down. But maybe we are lucky because in the 6 years usage, probably could count in my hand the number of emergency down times. One time, it was 2-3am in the morning on the phone with them working out what was eventually deemed a small hardware box issue the TELCO guys had to replace first thing in the morning.

Yet our bandwidth needs are probably less than what I need for a T1. So I am now researching VOIP to combine office lines and the T1. I have ABSOLUTELY no clue right now what are the options, but I do want/need the service. So I want to lower cost, but not sacrifice service requirements. I will pay extra for the piece of mind.

ATDT

I think it's the luck of the draw. I was a very early Bellsouth DSL user in my home. Way back when the actual Bellsouth truck would show up to make sure your NID was a "good" one. Over the next few months I coordinated 8 other installs of the service. Mostly for businesses. But the support was just plain lousy. When things went wrong at my house I learned to wait till 2 am when you could get through to a "real" tech. With the business setups it was very frustrating when things would go "offline" for a few hours and you couldn't get through to anyone before it magically came back up. The final straw for me was when a business customer paying for a block of 8 static IPs went down. Called BS tech support to see if anything special was up. "No, every thing's AOK." So before calling back for real, I took their modem and router to another nearby office with Bellsouth DSL. Plugged it in and everything came up fine. So I took it back to the problem location, called Bellsouth and told them what I'd found at both locations. They refused to work with me until I removed the router, installed PPPoE software on a standalone machine, and saw if that would get an IP address. I mean give me break, WHO would sign up for a block of 8 IP addresses and not plan to run a router AND have their computers on a network!

YMMV