Linking 3 remote offices to include Exchange functionality

[5tephen]

I'm taking on a new contract for an architects with 3 offices. 7 users in one and 10 at the other two. There is already VPN's linking them in place over standard ADSL lines but it's not really used. Too slow to copy CAD drawing files across so they just email each other. Obviously it sends at the same speed but email is more send-and-forget rather than waiting on a file copying across. Everyone just has a POP3 account.

The sites have basic file servers in place. I'd like to replace them because they are standard desktop pc's that could go any time.

What can I offer them given the limits of today's ADSL upload speeds? Exchange? Internal companyweb? DFS (most recent version seems well thought of)? My main issue is with Exchange with big attachments - I could connect everyone up to an Exchange server at one site but it's going to be seriously slow. Would like some sort of replication between them so that the users have the feeling of the attachment already being stored on their computer, rather than download the header then wait 10 minutes on the attachment to load.

Could I get away with SBS2003 at one site and Win2k3 servers at the other two, using companyweb etc from the SBS, or should it be Win2k3 throughout all three?

 

[5tephen]

Ok SBS2003 is out, you've mentioned a couple of things I wasn't aware of there so thanks
Joining a computer to a Win2k3-hosted domain - is it just a matter of adding the machine to the AD computers list at the server, then changing the settings on the actual computer? If so this would be handy as it would save running the bandwidth-hungry SBS wizard.

I would love to have the DFS in operation as to have their drawings duplicated across all offices would be a big benefit.
Any suggestions relating to Exchange?

 

[5tephen]

For whatever reason I didn't get email notification of replies to this thread Sorry for not checking this up.
The client has not proceeded with anything yet, I'm new to them so they're taking me on board for one office and see what I can do for them. It'll not be hard to improve on what the current outfit is providing.
mandelbug - DFS v2 only synchronises changes in segments of files as well afaik, not whole files. Also, I'd be setting the servers to only synchronise overnight so it'll keep things at least somewhat responsive during the day.
Remote desktop is out of the question since with CAD you need to see every last pixel response on the screen - it would be a big step back compared to what they're used to.

It's not so much the file sharing amongst the offices, they didn't place a big emphasis on this. But I'd like to get a centralised Exchange setup and am wondering whether it's best to have 3 Exchange servers duplicating to each other, or one server on SDSL (SDSL is only available on one of the offices) and have everyone on Exchange-over-HTTP.

I'll also admit to not having experience of setting up multi- global catalog exchange servers but I've no problem getting to grips with that. And I think this is the way to go to keep things responsive. Throw me your suggestions, for once I have a project with a decent amount of time to plan for

 

[5tephen]

Outlook Web Access is indeed excellent but obviously doesn't feel as 'complete' to use as Outlook - especially as that's what everybody has been using up until now. Especially the auto-complete when typing people's email addresses - 75% of people I have encountered using Outlook use this as their contacts list rather than clicking the To: button and finding it from contacts they should have saved.

The problem I'm having is with the size of the attachments. When someone gets a mail with a 2mb attachment, I don't want them to have to wait 10 minutes for it to open. I'd rather the email appeared 10 minutes late but the attachment opening instantly.

 

[5tephen]

Could you not use outlook over rpc?

I've set that up numerous times but never actually noted how it dealt with attachments - would this solve the problem? I thought it would download the message, then only download the attachment if the user clicked on it - I want the attachment to be fully downloaded before they see the email. Could you shed any light on this?

 

[5tephen]

Thanks for thatm quackers Must check that out.
I think the plan will be to have one Exchange server in the only office that can get SDSL, with everyone in the two remote offices using Outlook over RPC to connect to it; put a DC server in each of the other two offices for login purposes as mandelbug stated, with DFS also active on these servers, syncing nightly.
The only thing left to investigate is which would work better - a global catalog server at each site, or just one site with everyone using outlook-via-RPC. The latter would be easier to set up and maintain I suppose, but I'll have to read further into both. Thanks to you all for the advice

 

[5tephen]

They have 27 users according to your original post, you'd be crazy to put a server in each office for login purposes, there's absolutely no conceivable need for that. I designed AD for a global PR firm a couple of years ago, they had 2500 user and 6 servers handled all logins, centralized in major locations in pairs. You do not need servers on each site, unless the connection is so flaky they can't reliably get access to the main site.

Even then you'd be better getting 2x ADSL per remote office (from different providers for some resiliency), creating a IPSEC tunnel over each and load balancing between the tunnels using OSPF or something. Doubles your bandwidth and gives you resiliency.

Ok, fair enough if that is true for login purposes (that is impressive btw), but there will be a server at each site anyhow to host several gigabytes of files, so I may as well give that server the responsibility for logins for that site too, yes?
Regarding 2 ADSL connections - I've only set up paired connections before with Draytek 2900/2910 routers, and pretty much only for redundancy purposes. From what I could see, I couldn't get double the bandwidth as it only seemed to use one connection at a time. Is this true? This was for a single site btw, not for a VPN at the other end so maybe that works differently...?

 

[5tephen]

If there are file servers anyway, may as well use them for authentication.

I'd set up the ADSL as I described it with a pair of Cisco routers (yes, expensive I know). An 1841 with 2x ADSL WIC cards at each site means that you can have both ADSL connections at each end going into the same router. Once you've done that, set up a couple of tunnels between the sites (each tunnel going over different ADSL links to the other). Then you can set up a routing protocol of choice (OSPF or EIGRP) on the tunnel interfaces, if you assign them the same cost then you'll be able to round robin load balence between the links. Total cost is something like £700 per site for the router and ADSL cards and somebody who know how to configure that up on a cisco.

Thats my preferred way of increasing bandwidth for sites with only ADSL available and we've used it quite a few times with no problems.

The other option, if the client has the money, is to get a real business ISP involved to look at the connectivity and let you concentrate on the server side. They'll likely come up with something a lot like I've just suggested though, because they'll have somebody like me on their technical team to design solutions.

That will probably work out about the same or a bit less than the £250 per month I've seen quoted for SDSL connections. Plus the fact that it could be set up on the other two offices which don't have SDSL capability anyway. Will look into that. There is a local ISP who are quite reputable that I might approach but as you say, I can't see them straying much from what you've stated above.

*edit - I've just looked at a Draytek 2910 with two WAN ports connected. It's possible to create two tunnels with it - one using WAN1 only and the other using WAN2 only. If I set up two VPN's on it and two VPN's to a 2910 on another site, would that achieve something similar to the Cisco? I'm aware of the greater stability of the Cisco, but in what other ways does it improve on?