DSL vs. T1 2

[iolair]

I have been asked to expand our network. The plan is to add 50 users to their own network, which will be connected to the internet via a Cisco 2800 series router. Our local telephone company has given me the option of T1 or DSL, since we have copper and it would cost too much for fiber.

These 50 users will use the Internet for file transfers, audio and video downloads. (We're a technical school). Assuming that the DSL and T1 speeds are the same, which circuit would be better? In other words, would T1 allow more users to be faster than DSL, or does DSL have more capacity for 50 users? I can get either 1.544 T1 or 1.5 DSL, according to Ma Bell.

Iolair MacWalter
Network Engineer

 

[lerdalt]

First question I always have on a DSL line is what is the upload speeds? Then how will that impact what you are trying to do out there.

 

[ISPKing]

if it is the same speed go with a t1. Although upgrading to more bandwidth will be easier with dsl

CCNP

 

[burtsbees]

OK, guys, you have yet to really answer his question. You are now sentenced to the dungeon to eat nothing but mice and gruel.

A T1 has synchronous upload and download speeds (both 1.544Mbps), and a DSL line is asynchronous, with download at 1.5Mbps (as you say) and upload would be around 128-265K, but cannot be more than 384K (25% of download speed).

So, for file transfers, where you'd definitely benefit with a T1 (back and forth), that would be the reason to go T1. However, please keep in mind that you are only as fast as your slowest link...in other words, even if you did have 1.5Mbps download, you could only go as fast as the remote side's upload speed, and for your upload, only as fast as the remote side's download speed. However, with a T1, it should not matter---go with the T1.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[iolair]

Thanks for all the responses. Once again, burtsbees, you save the day. Thanks for the logical, clear explanation. T1 it is. Thanks!

Iolair MacWalter
Network Engineer

 

[ISPKing]

I tried, but my iphone was not cooperating. So i am excused from the dungeon.

CCNP

 

[burtsbees]

You just reiterated why the dungeon suits the crime---"iphone"...

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[ISPKing]

haha, i pre-ordered the iphone 4, plus i am rocking and incredible for my work phone.

CCNP

 

[HungryHouse]

Keep in mind, that not all DSL is made equal. Several flavors are not asynchronous.
What was said about the download being different than the upload is true in ADSL which is indeed the most popular form or commercially available DSL.


Real trouble call:
Customer: "I have a huge problem. A friend has put a screensaver on my computer, but every time I move the mouse, it disappears!"

 

[vipergg]

HungryHouse is correct there is a lot of different flavors of DSL. Depends on what the local lec supports.

http://www.buytelco.net/networkApplications.asp?ID=914

 

[PeterHurst]

As HungryHouse says not all DSL is the same.

If it's SDSL it can be 2.3Mb syncronous data over short distances, VDSL is faster again (10Mb I seem to remember)

BurtsBees is right about ADSL but if you can get a line with a 1Mb upstream (can be done in the UK) ( and say 8Mb downstream) then you'll probably be winning but you need to consider the traffic flow.

One extra thing with DSL - if it pops into a supplier's network check there's no contention (ie you share data paths with others so the throughput is actually less)

 

[iolair]

The main problem as far as the DSL goes here (I'm in the U.S.) is that we are far enough away from the CO that we can only get 1.5 as far as speed goes. So, until Ma Bell moves a DSLAM closer to us, I think we're pretty much stuck with the T1 line. I wish fiber were an option, but we're 2 miles from the nearest trunk line.

And I just don't trust wireless enough yet to try that. I know you can get some pretty good throughput that way as well, but line of sight and rights access isn't easy.

Iolair MacWalter
Network Engineer

 

[burtsbees]

Guys, you may as well be talking about a DS3---I was answering his post as it was written, paying particular attention to the last sentence...

"I can get either 1.544 T1 or 1.5 DSL, according to Ma Bell."

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[iolair]

Thanks, again burtsbees for cutting through the garbage and giving me a straight answer. As we used to say in our Novell CNE classes, "Life is good."

Iolair MacWalter
Network Engineer

 

[burtsbees]

Yous be welcome, mayn. Don't get me wrong---these guys are cool and know their shiznixit. Peter, Hungry and ISP are good with routers mostly, and viper is the switching god, especially with CatOS, though I know my fair share of CatOS. Most people shrug when they hear "CatOS", and I have no idea why---nice and simple, no hierarchical confusion, just "set", and away you go!

Glad you're straightened out, my friend. Be well.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[iolair]

Ah yes. CatOS. I miss the good ole days. I even miss DOS.

Iolair MacWalter
Network Engineer

 

[ISPKing]

^^too far.

CCNP

 

[burtsbees]

And that reminds me of yet another thing...where would we all be without ISP's precious opinion? I don't even want to think about it!

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[ISPKing]

very true, and thus A star for you my friend.....

CCNP