Windows Network Optimization

I am in charge of a Windows 2003 AD network with two main sites and 25 area
offices. The sites and area offices are connected using Cisco VPN hardware.
Our users in the area offices are complaining of slow access issues when
opening their files on the main file server that is located at one of the
main sites. Other than setting up local file servers in all the area
offices, or adding bandwidth beyond the T1s that are already installed, is
there anything that can be done to improve network responsiveness?

I understand that accessing files over a network is slow, and the users have
been told this, but I am wondering if there is anything that can be done.
What I am looking for are things like using some sort of caching, or other
techniques either software or hardware to improve the user's experience.

Any comments are welcome.

I would look at your server config and disk subsystem.

For example if using SATA drives I would switch to U320 Scsi drives 15K
rpms. If doing raid5 I would do raid 10 [faster raid level].

If going to one server I would replace with a cluster and a shared disk
array. Or distribute disk IO over various servers so you would have one
share/app on one system and a different share/app on another.

Idea here is to increase the responsiveness of the disk subsystem.

I would also have these vpns connect into a gigabit backbone switch. I
would do adapter teaming on each server with gigabit nics connected to the
gigabit backbone switch. This will increase the bandwidth to the disk
subsystem.

I should add that the area offices are on T1s and the main site with the file
server has 20Mbps plus bandwidth. The other main site has 4 T1s tied
together.

--Nick

"Nick" wrote:

> I am in charge of a Windows 2003 AD network with two main sites and 25 area
> offices. The sites and area offices are connected using Cisco VPN hardware.
> Our users in the area offices are complaining of slow access issues when
> opening their files on the main file server that is located at one of the
> main sites. Other than setting up local file servers in all the area
> offices, or adding bandwidth beyond the T1s that are already installed, is
> there anything that can be done to improve network responsiveness?
>
> I understand that accessing files over a network is slow, and the users have
> been told this, but I am wondering if there is anything that can be done.
> What I am looking for are things like using some sort of caching, or other
> techniques either software or hardware to improve the user's experience.
>
> Any comments are welcome.

Thank you, but I think the issue is more related to the remote network
connection rather than disk I/O or local network speed. The remote offices
are on T1s and the site with the file server has 20+Mbps in bandwidth. The
file server is a Dual Processor Dell 1855 Blade with hardware mirrored 300GB
SCSI drives.

--Nick

"Joshua Bolton" wrote:

> I would look at your server config and disk subsystem.
>
> For example if using SATA drives I would switch to U320 Scsi drives 15K
> rpms. If doing raid5 I would do raid 10 [faster raid level].
>
> If going to one server I would replace with a cluster and a shared disk
> array. Or distribute disk IO over various servers so you would have one
> share/app on one system and a different share/app on another.
>
> Idea here is to increase the responsiveness of the disk subsystem.
>
> I would also have these vpns connect into a gigabit backbone switch. I
> would do adapter teaming on each server with gigabit nics connected to the
> gigabit backbone switch. This will increase the bandwidth to the disk
> subsystem.

It'd be great if Microsoft paid attention here.
I feel your pain: I have 80ms latency between two sites (east-coast,
west-coast), and Windows networking is horrible: it's down to roughly a
megabyte/sec speed. both networks are gigabit connections in datacenters,
and the connection is over a VPN (but tested the speed outside the vpn as
well, that's not the limiting factor).

now here's the sad part: if you, like me, have this latency, then it's
"normal". look at this:
http://www.psc.edu/networking/projects/tcptune/ somewhere in the middle.
(tutorial section)

essentially, it means that you have to take your network connection speed
and multiply it by the latency between the two networks.
in my case, the number (1000Mbps times 0.08s) is roughly 8 Mbps. regardless
of the gigabit pipes, at full speed...

now, MS networking adds some really nice icing on the cake. read this:
http://www.commsdesign.com/design_co...cleID=55301653

Here's what it looks like, a little comparison, on the same lan, what speed
we're getting, playing with items like the TCP receive window buffer, and
such:

Speed (kbits)
Speed (kbits)

Buffer
FTP
SMB






Default
6046
1476


16384
1370
858


56700
5012
1471


131200
5521
1471





once again, it's on a gigabit lan, it's just that there's some latency. and
it's quite apparent that none of the tcp parameter tweaks help Windows
Networking.
But then, the question is, what would?


"Nick" <(E-Mail Removed)> wrote in message
news:7461E282-4D77-49AD-A4AE-(E-Mail Removed)...
> Thank you, but I think the issue is more related to the remote network
> connection rather than disk I/O or local network speed. The remote
> offices
> are on T1s and the site with the file server has 20+Mbps in bandwidth.
> The
> file server is a Dual Processor Dell 1855 Blade with hardware mirrored
> 300GB
> SCSI drives.
>
> --Nick
>

Thanks. Didn't really want to hear that, but that was what I suspected.

I have been watching the developments of Windows 2003 R2. Specifically the
rewritten DFSR which looks like it takes advantage of the WAFS technology
that is discussed in the commsdesign.com article you linked to. I guess the
solution will be to set up small servers in each area office running R2 and
set up DFSR.

I sure wish Ciso would incorporate this in to their routers. That would be
a great product!

Anyone have any other ideas or comments?

--Nick

"Gabor" wrote:

> It'd be great if Microsoft paid attention here.
> I feel your pain: I have 80ms latency between two sites (east-coast,
> west-coast), and Windows networking is horrible: it's down to roughly a
> megabyte/sec speed. both networks are gigabit connections in datacenters,
> and the connection is over a VPN (but tested the speed outside the vpn as
> well, that's not the limiting factor).
>
> now here's the sad part: if you, like me, have this latency, then it's
> "normal". look at this:
> http://www.psc.edu/networking/projects/tcptune/ somewhere in the middle.
> (tutorial section)
>
> essentially, it means that you have to take your network connection speed
> and multiply it by the latency between the two networks.
> in my case, the number (1000Mbps times 0.08s) is roughly 8 Mbps. regardless
> of the gigabit pipes, at full speed...
>
> now, MS networking adds some really nice icing on the cake. read this:
> http://www.commsdesign.com/design_co...cleID=55301653
>
> Here's what it looks like, a little comparison, on the same lan, what speed
> we're getting, playing with items like the TCP receive window buffer, and
> such:
>
> Speed (kbits)
> Speed (kbits)
>
> Buffer
> FTP
> SMB
>
>
>
>
>
>
> Default
> 6046
> 1476
>
>
> 16384
> 1370
> 858
>
>
> 56700
> 5012
> 1471
>
>
> 131200
> 5521
> 1471
>
>
>
>
>
> once again, it's on a gigabit lan, it's just that there's some latency. and
> it's quite apparent that none of the tcp parameter tweaks help Windows
> Networking.
> But then, the question is, what would?
>
>
> "Nick" <(E-Mail Removed)> wrote in message
> news:7461E282-4D77-49AD-A4AE-(E-Mail Removed)...
> > Thank you, but I think the issue is more related to the remote network
> > connection rather than disk I/O or local network speed. The remote
> > offices
> > are on T1s and the site with the file server has 20+Mbps in bandwidth.
> > The
> > file server is a Dual Processor Dell 1855 Blade with hardware mirrored
> > 300GB
> > SCSI drives.
> >
> > --Nick
> >
>
>

more bad news.
I have talked with MS support, to get some improvement, and the engineers
told me not to expect any improvement from R2. (and had no improvement
suggestions)

- Gabor

"Nick" <(E-Mail Removed)> wrote in message
news:4B899AF1-39A4-49E6-9385-(E-Mail Removed)...
> Thanks. Didn't really want to hear that, but that was what I suspected.
>
> I have been watching the developments of Windows 2003 R2. Specifically
> the
> rewritten DFSR which looks like it takes advantage of the WAFS technology
> that is discussed in the commsdesign.com article you linked to. I guess
> the
> solution will be to set up small servers in each area office running R2
> and
> set up DFSR.
>
> I sure wish Ciso would incorporate this in to their routers. That would
> be
> a great product!
>
> Anyone have any other ideas or comments?
>
> --Nick
>
> "Gabor" wrote:

We use a software WAFS product called Availl. It will do distributed file
locking and handle replication conflicts.
http://www.availl.com/

--
Sr. Network Administrator
MILLER LEGG
1800 N. Douglas Road
Pembroke Pines, FL 33024
CE News 2002 & 2003 "Top 50 Best Places to Work in USA"


"Nick" wrote:

> I should add that the area offices are on T1s and the main site with the file
> server has 20Mbps plus bandwidth. The other main site has 4 T1s tied
> together.
>
> --Nick
>
> "Nick" wrote:
>
> > I am in charge of a Windows 2003 AD network with two main sites and 25 area
> > offices. The sites and area offices are connected using Cisco VPN hardware.
> > Our users in the area offices are complaining of slow access issues when
> > opening their files on the main file server that is located at one of the
> > main sites. Other than setting up local file servers in all the area
> > offices, or adding bandwidth beyond the T1s that are already installed, is
> > there anything that can be done to improve network responsiveness?
> >
> > I understand that accessing files over a network is slow, and the users have
> > been told this, but I am wondering if there is anything that can be done.
> > What I am looking for are things like using some sort of caching, or other
> > techniques either software or hardware to improve the user's experience.
> >
> > Any comments are welcome.