LAN to LAN using DSL modems and ADSL line possible?

Your best solution would e to configure VPN servers on both sides. Your LANs will be connected to each other through VPN over your DSl lines. Now this is not the best solution, but it's cost cutting effective solution. I would've asked you to get ATM circuits, if you had a good budget.

I would keep it simple.  Get two Internet connections via DSL or Cable, or whatever.  Get two Linksys RV042 VPN capable broadband routers http://www.linksys.com/products/product.asp?grid=34&scid=29&prid=639.  Create a "branch office connection" - which will create a VPN connection to your two LANS.  Not only will this give you what you want, but will also provide a degree of protection for your two LANs as rudimentary firewalls.  You don't have to configure servers, maintain the OS, etc.  Cost about $300 US.

PS - those two routers can handle two connections each - so you could have load balancing and/or failover with 2 Internet connections at each site.

ADSL is async (big pipe down ,little pipe up)typical number is 1.5 mb down 128K up.
SDSL is symmetric(same bandwidth up as down)varies,but usually 1.1 mb up and 1.1 mb down .

You're not going to get 2mb cheaply,the closest you are going to get to it would be a T1.
They're about $450 to $600 US a month.

So what is it exactly you need to do with your network?
Are you hosting a webserver,file and print,and email?
Do you need to move large files between the servers?

If you answered no, then you might be able to use ADSL,if not then  a T1 or business DSL is what you need.

isaman07:

Are you suggesting VPN over a direct connection between the two dsl modems? Would the security offered by a VPN be required if the modems only phoned/answered each other? Also, what king of bandwidth would that give me?

pseudocyber:

So you are suggesting using the Internet as a backbone. Surely this would add overhead and security issues when compared to direct connections.  Also, we are hoping to connect the LANs together so that they can share our larger schools internet feed.

pgm554:

Main bulk of traffic will be web based, however we do have a database on the larger site we would like to share with the smaller school. This may prove problematic over a slow link, but are considering a remote access solution over the link (eg VNC / Win TS etc) for this purpose. Also pgm554, I am very interested in your descriptions of the ADSL / SDSL technology and abndwidth. "H"dsl and "x"dsl have been mentioned here, but again my query is whether the lines would be up to it. Putting it diagramtically (as far as ascii art goes):

"School A" SDSL MODEM <-->Local exchange("Adsl") line<-->"School B" SDSL MODEM

Whilst SDSL modems would be capable of higher data rates, would there be a bottle neck at the local exchange. eg would the link be limited to only 128k or something?

Thanks in advance,

Richard.

Richard I would forget ADSL for your purposes, the product is designed to connect to the Internet not for secure point to point. The modems would not be able to simple connect to each other through the ADSL network, instead they would use the Internet (hence the VPN suggestions to provide security). You will also probably find that the route from one school to the other would at least go to the chosen ISPs servers and back, so that 2-mile hop could be more like a few hundred miles.

You may be better served looking at BT KiloStream product http://www.westlakecom.com/bt_kilostream.htm or MegaStream (See http://www.bt.com and search for MegaStream)

How far apart are the two schools?

If within range a couple of wireless Access points may work?

snerkel,

Why could the adsl modems not connect to each other? A modem is a modem right? Set one to receive incoming calls, and the other to dial out? 56k analogue modems work that way. Am I missing something?

Just to clarify, I do not want to use the Internet as a backbone for a vpn.

I have seen the bt products. Looks like their 2mb Megastream may be an option, but I do not really need an always on solution. Prefer an on demand solution which is hopefully cheaper.

Still unsure if a 2mb link will be quick enough for our database application. (It is a VB app with forntend at workstation and backend on server).

kbbcnet,

Sorry - no line of sight, a pretty big hill in the way. A colleague is looking at OS maps to see how high a pair of masts would be needed - but I fear it will be very high, and I am 99% sure town planners would not approve.

Thanks for all the suggestions so far everyone. Much appreciated. If anyone can give a definitive answer on:
A) Why ADSL lines and sdsl modems point to point would not work, and
B) If 2MB would be fast enough for database access (<- sorry if this should be a new question).

then I will start handing out points.

Thanks again,

Richard.

Your 2 mile DSL may be pusing the distance limits which may not give you 2 Mbit.

Highwaterhead, you can't use DSL modems the way you're thinking of.  They don't talk directly to one another like Analog Modems do.  They talk to TELCO equipment which change the data to packetized network which flows over data links, not voice circuits.  Then there's the distance limitation inherent in DSL anway.

Check this out for more info:  http://computer.howstuffworks.com/dsl.htm

You can either get a connection to a providers "cloud" - Frame Relay, ATM, or MPLS or you can get a Point to Point connection like a T1 or Fractional DS3.  Some providers are now providing metro Ethernet connections.  It depends on where you are and what your local telco providers can give you.

Thanks to all for time and effort.
I am relatively new to posting questions, normally I just lurk. I had hoped to split the points between pgm554 and snerkel, but somehow I think I have missed the opportunity. Thanks again, and sorry if I did not split points as promised.

I haven't figured out how points are split, but I think you can ask somewhere to get the points split... sorry don't know how though.

Sure someone will be along with the answer

When you're ready to split points, scroll to the bottom and click on "split points".