Windows over T1 Frame Relay

[Guest]

We have a T1 frame relay pvc from Oregon to Kentucky that feels very slow.
Our bandwidth reports indicate that we are only using about 30% of the T1.
Our carrier suggest that it’s a problem with Windows, they say that because
we are on a 2000 domain there is a lot of network overhead. Our average
response time is about 100ms. It looks like adding another T1 isn’t going to
help us. Our carrier is recommending that we increase the packet size and TCP
window size on all of our Windows computers.
I’m hoping to find a better suggestion.

 

[Kurt]

First, try to prove him wrong. Disconnect everything except one computer at
each end and see if the situation improves. If you are using a VPN, likely a
good portion of the slowness is in the encryption/decryption processes.
100ms between Kentucky and Oregon seems pretty normal to me. With TCP,
latency at that level isn't really a problem. Have you considered a nice,
fast hardware VPN over the Internet? It's WAYYYYY cheaper than a
cross-country T1. And high-bandwidth Internet here in Washington State is
like $79.95 per month for 8 Mb (5+ T1s). It really depends on how much less
reliable your local DSL is at each end (when the fiber breaks here,
everything goes down, although point-to-point circuits come back up much
faster than DSL).

....kurt

 

[.]

What services? File sharing? Email? More details are needed.

File sharing is going to be poor because CIFS does not work well across a
WAN.

Do you have DNS servers on each end? If not, that's a good place to start.

Ray

 

[Guest]

KY has a DC with DNS and an Exchange 2000 server. The two main areas where we
see slowness is a KY pc reading a file from a Portland file server and KY PC
using IE to a portland Web server

 

[Guest]

T1's are still slow man. 1.544Mbps really isn't a hell of a lot of bandwidth.
You could seperate out your domain with 2 sites and enable DFS on a server
at each site and use FRS to replicate changes to these shares. This would
enable your users to have two identical data sets, 1 at each site, and get
their local one for access. This would speed it up tremendously. The only
time it might be slow would be during replication. You could also upgrade to
Windows 2003 R2 and use DFS replication instead of FRS which uses Remote
Differential Compression to only replicate delta changes instead of complete
files should the files change. This would maximize bandwidth. To increase
speed of Exchange, consider configuring Exchange cached mode so the entire
mailbox isn't opening across the WAN. As a last resort, go with a Terminal
Server.

 

[.]

IE shouldn't be an issue unless there's a proxy getting in the way that
shouldn't. Otherwise Rich Holmes has it nailed. Pre-R2 file sharing just
plain stinks across slow networks (slow for CIFS = > 20 ms)

Ray

 

[Guest]

Key here is your understanding of FR. You don't mention your CIR [committed
information rate] which is your TRUE bandwidth. Forget that crap about
"bursting up to port speed" Its a lie. With Frame you never get port speed
of 1.54mbps. You are getting an increment something like
64,128,256,512,768[if you are lucky].

Depending on changes DFS could saturate your wan link.

Internet and VPN is the better solution for cross state long distance.

 

[Guest]

Not using R2 and remote differential compression with DFS replication. Only
changes (Delta) to files are now replicated...not the whole file. Thus far
I've been amazed at how efficient it is.