dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
10563
share rss forum feed


EMTPtoPA

join:2007-11-30
Fort Collins, CO

ADSL vs dedicated T1?

I am installing a new internet line to a building. From the vendor's modem, I will distribute signal wirelessly via about 4 wired wifi access points.

The vendor claims that their dedicated T1 line (1.544 mbps up and down) will outperform the existing 20 mbps ADSL line. After several meetings with the new vendor, I am not convinced. How can this be? Aren't mbps the same world-around?

I have used DSL reports and other speed tests to check the existing line. It seems to give close to 20 mbps throughout the day.

Can someone suggest wording for a service-level agreement that I could propose to the new vendor? I'd like the performance risk to be on them...

Thanks,
Dave

hardly
Premium
join:2004-02-10
USA
What is the SLA on the existing 20 mbps ADSL line?


EMTPtoPA

join:2007-11-30
Fort Collins, CO
If you mean service level agreement, I'm not sure there is one. It is a Qwest DSL/business phone line. It's nominally rated at 20. I hope that answers your question.

Dave

Bink
Villains... knock off all that evil

join:2006-05-14
Castle Rock, CO
kudos:4
Reviews:
·VOIPO
reply to EMTPtoPA
T1 is legacy technology—there is NO WAY it will outperform a 20Mbps DSL line. That said, it MIGHT perform better than DSL when it comes to latency and jitter. If you decide to go with the T1, you should have good reasons for doing so/giving up the added ~18.5Mbps of DSL. As for an SLA, I’d require guarantees with regard to availability, bandwidth, latency and jitter—and stiff penalties if any of these are missed—otherwise there is very little reason to have a T1.


EMTPtoPA

join:2007-11-30
Fort Collins, CO
Thanks, I was afraid of that. It was a good salesperson who went around me and got access to the owner. My guess is that we will have dissatisfied users and will hav to but multiple T1's at great expense...

Dave

XIII

join:2010-06-16
Scottsdale, AZ
reply to EMTPtoPA
1.5 does not equal 20. Latency wise a T1 should be better than and xDSL line

bikenski

join:2010-06-22
Denver, CO
reply to EMTPtoPA
Whether the T1 can "outperform" ADSL depends on the type of traffic it is being used for. While the DSL line provides 20 Mbps of download speed, it's likely limited to 896 Kbps for uploads (unless it's VDSL2.)

If the line is being used to send data from the company to the Internet (ie. if the company hosts a web server, mail server, FTP server, etc.) then the T1 could be the better option. Also, if the circuit is primarily used for low-bandwidth, latency-sensitive traffic (VoIP, video conferencing, etc.) the T1 might also be the better option.

If, however, the line is used for employees to surf the web, and upload needs are minimal, then DSL is likely the better option.


EMTPtoPA

join:2007-11-30
Fort Collins, CO
Sorry I forgot to describe our use for this system!

The building is an apartment building with 48 small units and a small office. We plan wifi distribution throughout. We have no company technology. No servers, no voip.

Basically, we want our residents to be able to surf the web and access their email. We've noticed the trend that many want to stream videos, too.

Thanks!
Dave

bikenski

join:2010-06-22
Denver, CO
1.544 Mbps divided by 48 units would definitely lead to some very unhappy tenants! Do the residents have the option to purchase their own dedicated lines if they choose, or is this shared connection the only access available in the community?


EMTPtoPA

join:2007-11-30
Fort Collins, CO
The tenants do have the option to go it on their own, but the owner is striving to provide adequate wifi-based internet to them. Do you have a guess about what sort of building bandwidth would be required?

Thanks,
Dave

cooldude9919

join:2000-05-29
kudos:5
reply to EMTPtoPA
For this type of residential user setup you really just need lots of bandwidth, and though a t1 may be a more stable connection and have a better SLA, that really dosnt matter. Your users are obviously going to get better performance sharing 20mb download than than 1.5mb download. With residential users the bulk of the traffic is going to be download not upload, so even if the upload on the t1 is twice the dsl, thats really not going to help you much.

Not sure what you can even do with the t1 now, trying to do some type of bonding will probably just be a pain and not even net you that much more performance.

Even the 20mb might not be enough, but it all depends on what the users are doing and what they are expecting for free. One person could get 20mb in their apartment, yet you are trying to share it with up to 48 possible users. Now overselling is expected here, but as you said with more and more streaming video even 20mbps may not go as far as you think.

Bink
Villains... knock off all that evil

join:2006-05-14
Castle Rock, CO
kudos:4
Reviews:
·VOIPO
reply to EMTPtoPA
I concur with bikenski See Profile. If the primary purpose of this line is for ~50 people to surf the web, with today’s Internet YOU DO NOT WANT A T1 LINE. Unless the service you are providing is very cheap, people will likely pay ~50 a month and get 7-20Mbps for themselves.


caffeinator
Coming soon to a cup near you..
Premium
join:2005-01-16
WA, USA
kudos:4
reply to EMTPtoPA
All you need is a couple of torrent/heavy streaming users in that building and even 20mbs will be saturated anyways.

I hope you have a good router with QoS and restrictions.

billybob2

join:2003-07-23
Moline, IL

3 edits
reply to EMTPtoPA
As others have mentioned, the ADSL for 20mb download will be far superior for your needs than the T1 line. However, even the ADSL will cause you large problems because of the lack of upload capacity (you'll probably get approximately 1mbps upload at best). Get a couple people doing something simple like uploading their family photos and you'll find that the speed even on downloading becomes very slow while the upload capacity is saturated.

In a nutshell, it's likely neither the 20mbps ADSL nor the 1.5mbps T1 line will give you the service you need. I would guess you could probably get by with 20mbps download and 5mbps upload if that is an option, otherwise your best bet if fiber optics aren't available will be to look into something like SDSL which gives you the same speed in both directions (upload and download). Or check into Qwest's metro ethernet offering.

»www.centurylink.com/business/pro···net.html

Since you're running four wifi points, a couple things you can do to ease the problem would be the following. Set the WAN port speed on all four access points to 10mbps so that no single access point can saturate the full 20mbps download. Also, look for an access point that will allow you to only allocate "X" amount of bandwidth per client connected to it. If you can, limit each client connection to an access point to 2mbps download and 200kbps upload.

If you can do that, you'll probably maintain a functional network for the majority of your users, and anyone who desires faster speeds can go out and buy their own connection.


EMTPtoPA

join:2007-11-30
Fort Collins, CO
Thank you SOOOO much for the assessment and setup advice! I thought I was losing my mind listening to the T1 sales team stating that they could handle a bunch of streaming downloads with one or two T1's. Maybe we got sold a bill of goods.

I was thinking that I should have specified a verifiable SLA of, say, 10 simultaneous streams from Netflix. I doubt they would have agreed, though...

Any further thoughts for configuration, etc. VERY welcomed!

Dave

billybob2

join:2003-07-23
Moline, IL
So I take it from your last post that you're going the route of using a T1 or multiple T1's instead of the ADSL? If so, it's likely your tenants are going to be very unhappy if streaming video is in their realm of use. The capacity of a T1 line isn't even close to the required bandwidth you need unless you're going to have 1 person at a time watching Netflix. And any advantage of a T1 such as lower latency etc.. goes right out the window when the circuit is run to capacity.

T1 is still a great technology if you want to use it for phone service where you'll split it out into 24 voice channels (think 24 individual phone lines). T1 for internet though....not so much, not with today's uses anyway. For what a T1 cost, it wouldn't surprise me if you could install four 20mbps ADSL lines (one per wifi access point) for about the same cost per month. Four 20/1 ADSL lines would probably be adequate as long as people don't fill up the limited upstream capacity.


EMTPtoPA

join:2007-11-30
Fort Collins, CO
You nailed it.

2 bonded T1's were ordered for that building without my involvement. A very aggressive salesperson from a (national) comm. company called Cbeyond got to my part-time employer's owner and she signed the papers. Now, I have to put in wifi signal distribution within the building, and just take the signal that Cbeyond gives.

I have helped with wifi for some other buildings. Qwest or Comcast internet at 10-20mbps seems to work fine for those users. Again, the owner does not guarantee service or speed to her occupants. She just provides free wifi for them.

The Cbeyond salesperson convinced the building owner that 2xT1 was mo-better than 12-20mbps we can get from Qwest (for 1/4 the cost!), even for this non-business-critical service.

If all else fails, we'll try to get out of the contract with Cbeyond and order in ADSL.

Thanks for your help. Any guidance on configuration would be helpful!

In fact, my next task is to figure out how to distribute the wifi!

Dave

CappinHoff

join:2007-01-05
Des Moines, IA
reply to EMTPtoPA
The only way a T1 is better than ASDL is that it's symmetrical and more reliable. Other than that ASDL is better.

billybob2

join:2003-07-23
Moline, IL
reply to EMTPtoPA
said by EMTPtoPA:

You nailed it.

Thanks for your help. Any guidance on configuration would be helpful!

In fact, my next task is to figure out how to distribute the wifi!

Dave

If you want to avoid issues of double-NAT, what you'll want is a minimum of 4 static real IP addresses (ask for at least /29 sized network which would give you 6 usable IP addresses) to assign to your four access points. If you have no idea what a /29 is, look up the info on CIDR.

»en.wikipedia.org/wiki/Classless_···_Routing

Then I would run cat5 network cable from the location of each access point back to a central location where you will have the router that connects to Qwest and an ethernet switch to plug all of the access points into. The four access points will plug into a regular old ethernet switch, and the ethernet switch will plug into the router.

If none of this makes any sense to you, then I would plan on hiring someone familiar with setting up a computer network.


EMTPtoPA

join:2007-11-30
Fort Collins, CO
Wow, Thanks!

I followed all but the /29 part and am about to extend my meager knowledge by the link you provided.

I'll let you know how it goes.

Thanks!

Dave


DataRiker
Premium
join:2002-05-19
00000
reply to EMTPtoPA
The OP doesn't have ADSL which tops out at 8 mbit/s. Most likely VDSL or ADSL2+.

The upload on ADSL2 can be as high as 3 mbit/s depending on the vendor. VDSL about 10 mbit/s.

A T1 would be a horrendous downgrade.

Rockchuck
CenturyLink 1.5
Premium
join:2010-05-26
Boulder, CO
reply to EMTPtoPA
1. Cbeyond:
Press Cbeyond get out of the contract NOW. Once installation starts, that's that. Refer to Cbeyond's ratings on this site. This set of reviews »www.yelp.com/biz/cbeyond-atlanta-2 speaks for itself.

2. Diversity:
DS1 (T1), as has been stated, is an assured service...it's always 1.536/1.536Mbps, rain or shine. DSL and cable are "best effort" services, both in terms of throughput and reliability. It's advisable to install both DSL and cable (and the T1, if you're stuck with it), and run them into a link aggregator:

»www.peplink.com/solutions/intern···lancing/

If one service drops, the other(s) will carry on, providing slower but still usable internet. Anticipating your question: No, the speeds of the individual services will not add -- the aggregated services will only be as fast as the fastest individual service.

Note that simply buying two DSLs and a T1 will not accomplish diversity...it all arrives on the same telco cable. Seeing the local power company backhoe your 100-pr. buried cable is a heart-stopper, I can tell you.

3. Legal:
Be very sure to read the fine print (Acceptable Use Policy) covering each broadband service. Many ISPs, if not most, forbid resale; furnishing the service as an amenity may be permitted, but you don't know until you peer at the 8-point type, single-spaced pages of verbiage.


DataRiker
Premium
join:2002-05-19
00000
T1's can and do go down. In my experience just as much as DSL.

It might have a nice SLA attached but again, in my experience in means bill credits not stellar service.

Rockchuck
CenturyLink 1.5
Premium
join:2010-05-26
Boulder, CO

1 edit
I realize that the bulleted descriptions I wrote could be inferred as an firm endorsement of T1 over DSL. This isn't the case, however, there are salient differences:

> T1 delivers lower speed than today's range of xDSL offerings, but it's constant, bidirectional speed that isn't subject to external influences. Consumer DSL speed varies from day to day - old cable, rodent damaged cable, oversubscription, wet weather, hot weather... T1 forfeits less throughput to overhead than ADSL does: my Qwest/C-Link ADSL's Up to 1.5 label should really be Up to 1.3 On a Good Day.

> If a T1 goes down, the serving telco attends to it immediately, as specified by contract. Read anywhere else in these forums about how diligently most telcos do or do not respond to subscribers' DSL outages and slowdowns. Again, the descriptive phrase for consumer DSL service is "best effort".

Ironically, these days, most T1 spans are carried ("provisioned") between central offices and subscribers on 2- or 4-wire HDSL. However, these HDSL links are proprietary to the phone company - if there's a failure the telco gets right on it, in my experience, unlike consumer-class xDSL. In contrast, when responding to a complaint made about a flaky consumer ADSL, I've heard a telco field tech say to the subscriber, "We don't make enough money on it to justify spending any time on it [to get it to work properly]." They never say this to a T1 subscriber.

Going back to the OP, the situation is that a signed Cbeyond contract may compel using the dedicated T1, like it or not. If so, I would make the best of a costly misstep by aggregating it with whatever services the company could comfortably afford in addition to the cost of the T1: one or two DSLs and the highest-speed business-class cable offering, to enhance reliability through diversity. When a problem occurs, it's easier to tell the tenants that the connection will be "a little slow" until it's fixed, as opposed to having to confess that their internet will be out entirely for an unknown length of time. Once people get used to a service, free or not, they expect it to be there all the time.



DataRiker
Premium
join:2002-05-19
00000
reply to EMTPtoPA
Most of the above post is off base.

We are comparing a 20 mbit/s adsl2 ( or VDSL ) to a T1. The marginal speed fluctuations of a 20 mbit/s line is nowhere even close to T1 speed.

And as you correctly pointed out the vast majority of T1's are carried over xDSL making the comparison even more ridiculous.

T1 SLA's are extremely over rated and even more extremely over priced, especially for the OP purpose.