This infographic explains ransomware, type of malware that blocks access to your files or your systems and holds them hostage until a ransom is paid. It also examines the different types of ransomware and explains what you can do to thwart this sinister online threat.
Solved
Tuning TCP parameters to maximise throughput - Windows 2003 and 2008
Posted on 2014-12-30
Got 3 servers, A (Win 2008), B (Win 2003), and C (Win 2003) with network timeout issues between them.
Been testing with iperf and using various tcp window sizes.
A to B - works fine -high speed.
A to C - worksfine - high speed.
B to C - very slow. Increase in TCP windows size in iperf makes difference (But still not as fast as previous 2).
B to A - very very slow. Increase in TCP window size in iperf makes big difference.
C to A - same.
C to B - same.
I can sort of understand why B to C is slow (both are Windows 2003). These have not had TCP parameters tuned at all which I understand is possible on Windows 2003. My plan was to try increasing the TCP window size on these servers.
But B to A is from 2003 to destination of Windows 2008. I thought TCP was all sorted in 2008 and there was nothing to tune?
Been testing with iperf and using various tcp window sizes.
A to B - works fine -high speed.
A to C - worksfine - high speed.
B to C - very slow. Increase in TCP windows size in iperf makes difference (But still not as fast as previous 2).
B to A - very very slow. Increase in TCP window size in iperf makes big difference.
C to A - same.
C to B - same.
I can sort of understand why B to C is slow (both are Windows 2003). These have not had TCP parameters tuned at all which I understand is possible on Windows 2003. My plan was to try increasing the TCP window size on these servers.
But B to A is from 2003 to destination of Windows 2008. I thought TCP was all sorted in 2008 and there was nothing to tune?
[X]
Welcome to Experts Exchange
Add your voice to the tech community where 5M+ people just like you are talking about what matters.
- Help others & share knowledge
- Earn cash & points
- Learn & ask questions
2
2-
2
- +1
7 Comments
Active today
Is it too much to ask to just ditch Windows 2003? It's been around a long time and the end of support is very near. Not exactly a solution, but it's getting time to say goodbye. Networking in the later versions of Windows is greatly improved. I can actually push 1 GBs with the newer versions of Windows.
Active today
hi paul,
we need some more details ...
first - same network segment or routed
second - the question from pgm554: WAN or LAN connections
what do you mean with "works fine -high speed" and "very very slow"
i would suggest to not use iperf at the first steps.
copy a big file from one server to the other and look to the taskmanagers network-load. copy the file from the other server back to your server and look to the taskmanagers throughput.
post the results please.
if the difference from one direction to the other is really big (>50%) you have other problems than windows size. If one direction is OK, i think WS is not your problem. Changing WS is an option to optimize the throughput at WAN links but not the local LAN. Good description and calculation at http://bradhedlund.com/2008/12/19/how-to-calculate-tcp-throughput-for-long-distance-links/
We can search and find these errors if you provide us with many details as possible.
we need some more details ...
first - same network segment or routed
second - the question from pgm554: WAN or LAN connections
what do you mean with "works fine -high speed" and "very very slow"
i would suggest to not use iperf at the first steps.
copy a big file from one server to the other and look to the taskmanagers network-load. copy the file from the other server back to your server and look to the taskmanagers throughput.
post the results please.
if the difference from one direction to the other is really big (>50%) you have other problems than windows size. If one direction is OK, i think WS is not your problem. Changing WS is an option to optimize the throughput at WAN links but not the local LAN. Good description and calculation at http://bradhedlund.com/2008/12/19/how-to-calculate-tcp-throughput-for-long-distance-links/
We can search and find these errors if you provide us with many details as possible.
Active today
Here's my goto on tuning older versions of Windows:
http://www.psc.edu/index.php/networking/641-tcp-tune#WindowsXP
http://www.psc.edu/index.php/networking/641-tcp-tune#WindowsXP
Active today
you have a 1GBit WAN connection, between 3 locations, right?
at every location you have one server?
Which type of WAN do you use (dark fibre, provider MPLS, ...)
what are the latencies (or ping times) from
A to B
A to C
B to C
and the opposite direction?
if the lowness occurs only if WAN connections affected (within the locations the copy from server to client and backwards are fast?) the MTU is a possible problem too.
try reduce the MTU radical (i use MTU of 800 or 1000 for testing)
another possible problem is duplex mismatch. it is typical if one direction is fast the other very slow.
you should select the automatic duplex settings at all ports (servers,switches,routers,
with wireshark you should see packet retransmissions...
at every location you have one server?
Which type of WAN do you use (dark fibre, provider MPLS, ...)
what are the latencies (or ping times) from
A to B
A to C
B to C
and the opposite direction?
if the lowness occurs only if WAN connections affected (within the locations the copy from server to client and backwards are fast?) the MTU is a possible problem too.
try reduce the MTU radical (i use MTU of 800 or 1000 for testing)
another possible problem is duplex mismatch. it is typical if one direction is fast the other very slow.
you should select the automatic duplex settings at all ports (servers,switches,routers,
with wireshark you should see packet retransmissions...
Featured Post
Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.
Question has a verified solution.
If you are experiencing a similar issue, please ask a related question
OfficeMate Freezes on login or does not load after login credentials are input.
The recent Microsoft changes on update philosophy for Windows pre-10 and their impact on existing WSUS implementations.
This tutorial will walk an individual through the steps necessary to configure their installation of BackupExec 2012 to use network shared disk space.
Verify that the path to the shared storage is valid and that data can be written to that location:…
This tutorial will give a short introduction and overview of Backup Exec 2012 and how to navigate and perform basic functions.
Click on the Backup Exec button in the upper left corner. From here, are global settings for the application such as conne…
Suggested Courses
Course of the Month7 days, 8 hours left to enroll
715 members asked questions and received personalized solutions in the past 7 days.
Join the community of 500,000 technology professionals and ask your questions.