TCP Optimizer Help
Under Construction is an understatement.
Notes: This documentation is for version 2 of the
Please also see the
TCP Optimizer FAQ for answers to frequently asked questions.
Table of Contents
2. Using the program
3. General Settings
3.1 Connection Speed slider
3.2 Network Adapter selection
3.3 TCP Receive Window
3.4 MTU Discovery
3.5 Black Hole Detect
3.6 Selective ACKs
3.7 Max Duplicate ACKs
3.8 Time to Live
3.9 TCP 1323 Options
4. Advanced settings
4.1 Internet Explorer Optimization
4.2 Host Resolution Priority
4.3 Type/Quality of Service
4.4 DNS Error Caching
4.5 LAN Browsing speedup
4.6 LAN Request Buffer
5. Largest MTU
9.1 File Menu
9.2 Preferences Menu
Appendix A - Program Changes
The TCP Optimizer is a
program designed to provide an easy, intuitive interface for
tuning TCP and IP related parameters in the Windows Registry. It takes into
account all related RFCs, the Microsoft TCP/IP implementation oddities,
verifies all Registry locations for the same TCP/IP parameters (ICS
Sharing, AOL protocol MTU, etc), only ads the necessary Registry parameters, and
overall aids in making the whole "tweaking for speed" experience a breeze.
It is downloadable from here:
SG TCP Optimizer.
In the following chapters, you will find short descriptions of all the
settings and all aspects of the functionality of the TCP Optimizer. In addition
to this documentation, you can also check the
TCP Optimizer FAQ,
as well as the
Tweaking forum. We'd also appreciate any feedback about the program, please
contact the webmaster or post in our forums with any suggestions for additions
or changes to either the program or this documentation.
2. Using the program
If you do not feel like reading the entire documentation below, or you simply need
the tweaks NOW, without spending time in learning the meaning of all those settings, you can use the
Optimizer by following these short instructions:
- Choose your maximum Connection Speed from the slider bar (the maximum
available bandwidth, in kilobits per second)
- Choose your Network Interface, or check to Modify All Network Adapters
- Pick "Optimal
settings" from the radio-buttons near the bottom of the program
- Click on the "Apply changes" button and reboot
The Optimizer can do
all the rest for you (including a backup of the current registry settings, so
you can revert the changes if you wish). The new version of the program includes
a preview of all changes after hitting the "Apply changes" button and before
actually editing the Windows Registry.
You can also use the Optimizer to easily apply custom values, test with
different settings, and learn a bit more about tweaking and TCP/IP in general.
We strongly recommend getting familiar with the settings, and learning what
aspects of your connection they affect first. Also, note that some of the
program tabs (Largest MTU, BDP, Latency) can be used as a learning tool without
making any changes to the Windows Registry.
The 3 radio buttons at the bottom of the program show the relevant "Current
settings" as set in the Windows Registry, the Optimizer recommended "Optimal
settings", or allow for "Custom settings" for the more advanced user to test
with different values.
Please see the following chapters for definitions and detailed descriptions
of all options in the TCP Optimizer.
Note: You should be logged in with an account with administrative
privileges to be able to write to some of the Registry keys and use the program
to its full potential.
3. General Settings
This tab contains all the important tweakable TCP/IP parameters.
Connection Speed (in kilobits per second) - you have to choose your
maximum available bandwidth here. The Optimizer will base any "Optimal settings"
recommendations on the connection speed you choose in this slider bar. Please
note it is an approximation of your maximum available bandwidth, it does not
have to be exact.
Network Adapter selection - you should have a list of all present network
interfaces in the system. When you select an adapter, using this pull-down menu,
its IP address will be shown in the lower-right of this section. Note you can
also choose to modify all network adapters at the same time, or tweak without
modifying any of their settings.
You also have the option to type a
a custom MTU value (that will be used to recommend RWIN). Generally, MTU can
safely be set at 1500, however some types of connections, and some routers use
smaller values. It is only necessary to edit the MTU value in such special
cases. For example, the maximum MTU value for Windows XP PPPoE encapsulation is
1480 (even though other PPPoE implementations can use as high as 1492).
Note: In some rare cases, it is possible that your desired network device is
not correctly identified by the Optimizer. That does not affect the program
performance much, and you should simply choose "Modify All Network Adapters" in
such cases. We'd also appreciate you contacting us with the exact device, so we
can improve the program.
TCP Receive Window (a.k.a. RWIN) - this buffer is the single most
important factor in tweaking your TCP/IP parameters. A small RWIN value limits
your maximum throughput (the server waits for acknowledgements of received
packets), one much larger than needed by your connection can have a negative
effect on your connection as well. Here is some history on RWIN, and all the
considerations in choosing an "optimal" value:
Originally, when the TCP protocol was developed, there were only 16 bits in
the TCP header reserved for the size of this buffer, allowing for a maximum
value of 2^16 (65535, if you start counting from 0). With faster high-latency
networks this value proved insufficient, and RFC 1323 introduced additional "TCP
Options", allowing for larger RWIN values. It is accomplished by bit shifting,
or multiplying the original unscaled RWIN value (up to 65535 bytes) in the TCP
header by a scale factor, power of 2.
The TCP Optimizer recommends an optimal TCP Window value considering all the
- Bandwidth * Delay product based on the chosen maximum connection speed and
maximum anticipated latency.
- RWIN (both scaled and unscaled) multiple of MSS, for maximum optimization.
- Proper RFC 1323 scaling for RWIN values larger than 65535.
- largest optimal unscaled RWIN (MSS multiple) used for all RWIN values over
MTU Discovery (RFC 1191, EnablePMTUDiscovery) - We recommend enabling (choosing "Yes") this setting.
MTU Discovery determines whether TCP uses a
fixed, default maximum transmission unit (MTU) or attempts to find the actual
MTU. In some versions of Windows, if MTU Discovery is disabled the OS uses an
MTU of 576 bytes for all connections to computers outside of the local subnet.
If enabled, TCP attempts to discover the MTU (largest packet size) over the path
to a remote host.
Black Hole Detect (EnablePMTUBHDetect) - The recommended optimal
setting in the TCP Optimizer is "No".
Enabling this setting causes TCP to try to detect black hole routers while doing
Path MTU Discovery. A black hole router does not return ICMP Destination
Unreachable messages when it needs to fragment an IP datagram with the Don't
Fragment bit set. TCP depends on receiving these messages to perform Path MTU
Discovery. With this feature enabled, TCP tries to send segments without the
Don't Fragment bit set if several retransmissions of a segment go
unacknowledged. If the segment is acknowledged as a result, the MSS is decreased
and the Don't Fragment bit is set in future packets on the connection. Enabling
black hole detection increases the maximum number of retransmissions that are
performed for a given segment. Unless you are dealing with a relatively archaic
network, or running a server, this setting does not make much visible
difference, and can in fact waste bandwidth if enabled.
Selective ACKs (SackOpts) - the recommended setting is "Yes".
This parameter controls whether or not SACK (Selective Acknowledgement) support
is enabled, as specified in RFC 2018. SACK is especially important for
connections using large TCP Window sizes.
Max Duplicate ACKs (TcpMaxDupAcks) - range is 1-3, the recommended
value is 2.
This parameter determines the number of duplicate ACKs (acknowledgements) that
must be received for the same sequence number of sent data before "fast
retransmit" is triggered to resend the segment that has been dropped in transit.
Time to Live (TTL, DefaultTTL) - recommended value is 64.
This setting specifies the default time-to-live (TTL) value set in the header of
outgoing IP packets. The TTL determines the maximum amount of time in seconds
(and the number of hops) that an IP packet may live in the network without
reaching its destination. It is effectively a limit on the number of routers
that an IP packet is allowed to pass through before being discarded. It does not
directly affect speed, however a value
that's too small can cause packets to be unable to reach distant servers at all.
A very large value, on the other hand might take too long to recognize lost
TCP 1323 Options (TCP1323Opts) - we recommend having only "Window
This parameter controls RFC 1323 time stamps and window-scaling options. The
"Window Scaling" part allows for RWIN (TCP Window) values over 65535. Timestamps
add another 12 bytes to the header of each packet, and are only necessary in
connections with increased packet loss.
This tab contains additional tweaks, that have a smaller, but still
noticeable effect on TCP/IP performance. Generally, the tweaks on this page are
not directly related to throughput. Some of the tweaks in this section of the
Optimizer might be related only to specific aspects of networking, such as Web,
or LAN browsing, hostname resolution speed, etc.
Internet Explorer Optimization
By default, the HTTP 1.1 specs allow for only 2 concurrent connections to a
Web server. That means, while downloading a web page you can only get 2 files at
a time. Note that a single page usually includes tens (sometimes hundreds) of
images, each initiating a separate request to the server. Increasing the default
to ~10 can provide a considerable visible boost in web page loading time,
especially for broadband internet connections. There are two parameters in this
section, MaxConnectionsPerServer, and MaxConnectionsPer1_0Server,
corresponding to HTTP 1.1 and 1.0, respectively. We recommend setting both to
the same number, between 4 and 10.
Host Resolution Priority
This section improves DNS and hostname resolution in general. It helps web
pages load faster, and has negligible effect on downloads. For more information
on what/how this tweak operates, check our
Priority Tweak article. We recommend using the Optimal values (5,6,7,8).
Type/Quality of Service
QoS (Quality of Service) and ToS (Type of Service) have to do with support
for priority traffic.
QoS is enabled by default in Windows XP, and can limit available bandwidth in
order to accommodate high-priority traffic, when present. The Optimizer only
changes the QoS value if it is already present in the registry. It is in the
Registry only if the QoS Packet Scheduler is installed (can be added from
the Network Adapter Properties). We recommend having the QoS Packet Scheduler
uninstalled, or/and setting the QoS: NonBestEffortLimit Optimizer setting
ToS (Type of Service, RFC 791, RFC 1812)
is a field of the IP header, designed to also carry quality of service features,
such as prioritized delivery for IP datagrams. It is not widely used, and it has
been redefined and superseded by a newer standard called Differentiated
Services (DiffServ) and defined in
RFC 2474 ,
RFC 2598. DiffServ increases the number of definable priority levels
by reallocating bits of an IP packet for priority marking. The TCP Optimizer
allows for ToS/DiffServ editing, although it is an advanced setting, probably
beyond the scope of regular residential broadband tweaking. If you feel
comfortable editing this value, you might also want to note possible
conflicts with using some ToS values in a DiffServ environment, as described in RFC 2873.
ToS other than 0 is only available if ToS: DisableUserTOSSetting is present, and set to "0" in the
Optimizer. If enabled, the ToS: DefaultTOSValue can be set to a specific number,
(which is probably beyond the scope of this help file, but is somewhat explained
below - feel free to
read the related RFCs referenced above for more info). If we must make a recommendation,
here are some good DefaultTOSValue numbers that are valid, and with high
precedence in both ToS and DiffServ environments:
- DefaultTOSValue = 80 - (010 100 00 binary). This setting should
be tried first. It is not very aggressive, but it takes precedence over
regular traffic and asks for low delay. For ToS, you get immediate
precedence, low delay. For DiffServ, you get AF22 - class 2
traffic, medium drop probability.
- DefaultTOSValue = 136 - (100 010 00 binary). This is a moderately
aggressive precedence setting. For ToS, you get flash override
precedence, high throughput. For DiffServ, you get AF41 - class 4
traffic, low drop probability.
- DefaultTOSValue = 184 - (101 110 00 binary). This is a very
aggressive setting, that might introduce some packet loss - it is usually
only recommended for audio/video applications. For ToS, you get critical precedence,
low delay, high throughput. For DiffServ, you get EF - Expedited
Forwarding, high priority traffic, but with higher drop probability.
The tables below explain the ToS and DiffServ values in more detail so you
can choose your own numbers
ToS Field in Detail:
000 (0) - routine
001 (1) - priority
010 (2) - immediate
011 (3) - flash
100 (4) - flash override
101 (5) - critical
110 (6) - Internetwork Control
111 (7) - Network Control
0 - normal
1 - low
0 - normal
1 - high
0 - normal
1 - high
0 - normal
1 - low
(Must Be Zero)
Note: The field is 8 bits in the IP header, first 3 define precedence, then
one each for delay, throughput, reliability, cost and a checking bit as
illustrated by the table above.
|DSCP (Differentiated Services Codepoint)
Class selection is in the first 3 bits, and maps directly to the IP
Precedence bits from the ToS table above.
Currently unused, best kept at 00 for backward compatibility with ToS.
DiffServ Codepoints (first 6 bits) in order of precedence:
||000 000 (00)
||class 0, default (routine)
||001 000 (00)
||class 1 - similar to the ToS Precedence (priority)
001 010 (00)
AF (Assured Forwarding) class 1 - low drop precedence
001 100 (00)
AF class 1 - medium drop precedence
001 110 (00)
AF class 1 - high drop precedence
||010 000 (00)
||class 2 - similar to the ToS Precedence (immediate)
010 010 (00)
AF class 2 - low drop precedence
||010 100 (00)
AF class 2 - medium drop precedence
010 110 (00)
AF class 2 - high drop precedence
||011 000 (00)
||class 3 - similar to the ToS Precedence (flash)
011 010 (00)
AF class 3 - low drop precedence
011 100 (00)
AF class 3 - medium drop precedence
011 110 (00)
AF class 3 - high drop precedence
||100 000 (00)
||class 4 - similar to the ToS Precedence (flash override)
100 010 (00)
AF class 4 - low drop precedence
100 100 (00)
AF class 4 - medium drop precedence
100 110 (00)
AF class 4 - high drop precedence
||101 000 (00)
||class 5 - similar to the ToS Precedence (critical)
101 110 (00)
Expedited Forwarding (recommended for video/audio - high priority,
higher drop probability)
||110 000 (00)
||class 6 - similar to the ToS Precedence (Internetwork Control)
||111 000 (00)
||class 7 - similar to the ToS Precedence (Network Control)
- The DiffServ column shows the 8-bit decimal equivalent that should be used in
the TCP Optimizer for the "DefaultTOSValue". The value is obtained by appending
two 0s to the 6-bit DiffServ codepoints. Note to set any ToS other than 0 in the
Optimizer, you also need to set "DisableUserTOSSetting" to "0" (non-empty zero
- Higher class traffic takes precedence. Values not in the above table can get
reset to the default (0), or have the connection reset.
Some routers may change, or reset the ToS/DiffServ value to 0 regardless of the
DNS Error Caching
Windows has built-in DNS (Domain Name System) caching, which basically caches
resolved hostnames for faster access and fewer DNS lookups. This is generally a
great feature, with the only downside that failed DNS lookups get cached by
default as well... When a DNS lookup fails (due to temporary DNS problems),
Windows still caches the unsuccessful DNS query, and in turn fails to connect to
a host regardless of the fact that the DNS server might be able to handle your
lookup seconds later. One can manually flush failed DNS lookups by typing
ipconfig /flushdns in Command prompt... Or you can simply set the 3 values in
the Optimizer to "0", and it will set the relevant Registry settings.
Note: Seems Microsoft changed the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters\NegativeCacheTime Registry
entry in Windows 2000to
in Windows XP and 2003 server. We have updated this in the 2.02 version of the
LAN Browsing speedup (disabling the Network Task Scheduler)
This tweak disables searching networked computers for scheduled tasks (when set
to "Optimized" in the program). It reduces the long wait when opening network
folders, and speeds up LAN browsing.
LAN Request Buffer Size (reduces network delay)
In higher latency Networks, delays may be encountered with the default request
buffer size (4356 decimal). The range of this parameter is 1024 - 65535 bytes.
Testing has shown that, in most standard Ethernet environments, if memory is
available 16384 bytes is a better choice. This tweak only applies to LANs, and
helps with slow browsing of large directories.
5. Largest MTU
This section aids in finding the largest possible non-fragmented packet
between your PC, and a server. You can specify an URL, click Start, and have the
program ping the specified server with different packet sizes, until it finds
the largest possible packet before fragmentation occurs. The largest
non-fragmented MTU is important in that it represents the optimal MTU value on
that particular path.
A large MTU value helps in maximizing data vs. header size for a particular
data segment. Fragmentation and reassembling of packets can cause slowdowns, and
introduces more header overhead as well. That is why the largest non-fragmented
MTU value for your network connection is a significant factor in tweaking. Once
the program finds the largest non-fragmented packet, it can be plugged in the
MTU value in the General Settings tab.
Note that for this to work, it is best to set your MTU value to 1500
temporarily, since the largest non-fragmented MTU us also bound by the MTU value
on your end.
6. BDP (Bandwidth * Delay
This section contains a Bandwidth * Delay calculator. The BDP is a very
important concept in TCP/IP Networking. It is directly related to the TCP Window
(RWIN) value, in that it represents a limit to the possible throughput. BDP
plays an especially important role in high-speed / high-latency networks, such
as most broadband internet connections. It is one of the most important factors
of tweaking TCP in order to tune systems to the type of network used.
The Bandwidth*Delay Product, or BDP for short determines the amount of data
that can be in transit in the network. It is the product of the available
bandwidth and the latency, or RTT.
The BDP simply states that:
BDP (bits) = total_available_bandwidth (bits/sec) x round_trip_time (sec)
or, since RWIN/BDP is usually in bytes, and latency is measured in milliseconds:
BDP (bytes) = total_available_bandwidth (KBytes/sec) x round_trip_time (ms)
What does in all mean ? The TCP Window is a buffer that determines how much data
can be transferred before the server waits for acknowledgement. It is in essence
bound by the BDP. If the BDP (or RWIN) is lower than the product of the latency
and available bandwidth, we can't fill the line since the client can't send
acknowledgements back fast enough. A transmission can't exceed the (RWIN /
latency) value, so RWIN needs to be large enough to fit the
maximum_available_bandwidth x maximum_anticipaded_delay.
This section of the program is simply a tool for testing the latency of your
network/internet connection. You can choose a number of hosts, a number of pings
per host, and ICMP packet size. After clicking start, the tool will
consecutively ping all hosts, then provide maximum and average latency
measurements in milliseconds, as well as packet loss indication (if present).
This tool can be used to effectively estimate the maximum anticipated latency
for BDP/RWIN calculations. In order to do that, we recommend using a larger
number of hosts than the default 5, and a larger packet size (since larger
packets tend to have a bit higher latency). Then, as an estimate of your maximum
anticipated latency, rather than using the Maximum RTT, use the average RTT,
multiplied by two.
- Pinging hosts uses ICMP, rather than TCP. Some routers give very low
priority to ICMP traffic, and as a result you may experience a higher
percentage of packet loss.
- Larger packets have a bit higher latency
- RTT varies with time
of day, network congestion, etc.
- Some nodes might choose to drop repeated
ICMP requests when congested, or ignore them all together.
This section of the Optimizer has been improved to include an actual Registry
Editor. It is a direct interface to the Windows Registry, and only intended for
advanced use ! Please only use it carefully, and at your own risk.
Note that the Registry editor only includes TCP/IP, and some related hives of
the Windows Registry.
To use it, simply navigate to the appropriate key you wish to edit in the
left section of the editor, then work in the right section, by either choosing a
value/key and editing it, or adding a new one. All available actions for the
currently active window/key/value are reachable by right-clicking on them.
The File Pull-down menu contains a number of options for backing up,
as well as exporting and importing all the related TCP Optimizer settings. Those
options can be shared between users, they contain information about empty keys,
values to remove/add/edit and all relevant parameters to clone the exact state
of the related settings to another machine, or save them for your own reference
The Preferences menu, pictured on the right has two sections. The
first one, "Maximum Latency" is a number in milliseconds, that is used in
calculating the optimal RWIN value. It affects all the "Optimal settings"
recommendations of the program, so if you're not sure what it does, leave it at
the default 500ms. Basically, the larger this number, the larger RWIN values the
program is going to recommend under "Optimal settings" for the same connection
speed, and vice versa.
The second section in the Preferences menu, "Latency tab: hosts to ping"
contains a list of URLs, used in the Latency section of the program for
measuring current RTT (round trip time, delay, ping, latency) to multiple hosts.
The Help Menu of The Optimizer simply contains a link to this documentation, as well
as the Software License Agreement, and some general information about the program.
Appendix A - Program Changes
TCP Optimizer v. 3.0.8 (09.17.2011):
- Added NetworkThrottlingIndex gaming tweak to the Advanced tab
- Changed "MaxUserPort" optimal value from 65535 to 65534.
- minor internal improvements
TCP Optimizer v. 3.0.7 (03.22.2011):
- Improved international Windows support (MTU should be correctly recognized and modified for most countries/network adapters)
- Increased MTU limit to 9000 to accomodate some Gigabit connections
- Changed ECN Capability optimal recommendation in General tab based on user feedback and issues with some US ISPs
- Fixed a minor issue with TcpAckFrequency and TcpDelAckTicks not applied only in "custom" mode in some cases where the Network adapter is not recognized
TCP Optimizer v. 3.0.6 (10.06.2010):
- fixed a possible program crash condition under Windows 2008 Server R2
- added traceroute capability to the MTU/Latency tab
- improved netsh current settings reading under Swedish versions of Windows
TCP Optimizer v. 3.0.5 (09.16.2010):
- fixed a 3.x Windows XP bug - only when choosing to "modify all network adapters", two advanced settings (TcpAckFrequency and TCPDelAckTicks) were set incorrectly.
- Improved International Windows support (reading current netsh settings).
- minor internal improvements
TCP Optimizer v. 3.0.4 (09.06.2010):
- Improved International Windows support - netsh current settings in the General tab should now be read correctly for many languages
- minor internal improvements
TCP Optimizer v. 3.0.3 (07.29.2010):
- changed 64-bit OS handling to avoid 32-bit access issues causing some netsh settings not to remain persistent after reboot
- changed Direct Cache Access (DCA) and NetDMA (TCPA) handling in Windows 7
- minor internal improvements
TCP Optimizer v. 3.0.2 (07.12.2010):
- added "Dynamic port allocation" (MaxUserPort, TcpTimedWaitDelay) for Windows XP/2003
- added "Checksum Offloading" (DisableTaskOffload) setting for Windows 7/Vista/2008/XP/2k3
- added a "Copy current settings" option to the File menu for easy sharing of current settings (forum posting, etc.)
- fixed incorrect error message under Chinese versions of Windows 7 x86.
TCP Optimizer v. 3.0.1 (07.09.2010):
- fixed reading current settings correctly under XP
- temporarily disabled incorrect error message under Windows 7 x64 after applying changes
- Enabled Gaming tweak (disable Nagle's algorithm) in Windows XP mode
- minor cosmetic/message updates
TCP Optimizer v. 3.0 (RC1, 07.07.2010):
- complete rewrite of the General tab to support Windows 7, Vista, and Server 2008 - different look and settings under Windows 7/Vista vs. XP/2k
- increased connection speed slider to 100+ Mbps
- added an easier method to revert to the Windows default settings per OS version
- added options to reset TCP/IP and Winsock
- Combined Latency and BDP tabs into one, updated Largest MTU algorithm and sites to ping
- various minor improvements
Known issues: when applying some custom settings, you may see an error: "Set global command failed on IPv4 The parameter is incorrect". The settings are being applied (can be verified by restarting the Optimizer and checking "current" settings), just the error is incorrectly displayed.
Changes in TCP Optimizer v. 2.0.3 :
- Under Optimal or Custom mode, when PPPoE is checked, and the MTU is not
modified manually, the displayed 1492 MTU is now correctly applied to the
- If MTU is set to a value outside the valid range, and the user changes
current/optimal/custom mode, the value is now properly reset to 1500.
- The Latency tab will account for, and discard incorrect negative RTT
values sometimes returned by servers. Such values will no longer count
towards the min/max/avg calculations.
Changes in TCP Optimizer v. 2.0.2 :
- Added all virtual Network Adapters to the list of NICs.
- Changed the NegativeCacheTime Windows 2000 entry to
MaxNegativeCacheTtl for Windows XP and 2003 Server (DNS Caching).
- Added Scaled RWIN and Tcp1323 Options for Windows 95 machines as
requested (a MS update to Windows 95 is also necessary for this to work)
- Removed the ToS/QoS control box frame, LAN Browsing speedup,
and LAN Request Buffer size from Windows 9x Advanced settings.
- Changed custom mode to display the current values by default, rather
than optimal ones.
- Fixed the Windows 9x Advanced settings optimal/custom modes to display
the correct Host Resolution Priorityy
- Fixed the RWIN calculation to take into account custom latency selection
after program restart.
- Updated the Windows 9x RWIN calculation to match the Windows XP/2k/2k3
Changes in TCP Optimizer v. 2.0.1 :
- Fixed a bug where DefaultTTL was set to "0" instead of "64" under
"Optimal settings" in Windows 9x.
- Fixed the "LAN Browsing speedup" to correctly show "Optimized" under current
settings when applicable.
- Changed "Connection speed" slider bar to accommodate faster broadband
connections as per users' requests.
- Changed "Connection speed" slider bar to retain last user-selected speed
setting after program restart.
Changes in TCP Optimizer v. 2.0.0 (from version 1.0):
- Added a new tab with a BDP (Bandwidth*Delay Product) calculator
- Registry tab is now an editor, users can edit/add/delete keys in related
- Changed the connection speed to a more flexible slider bar.
- Changed the RWIN calculation to reflect various speeds, optimal RWIN is
now recalculated on the fly.
- Added Afd check for the RWIN value, to avoid confusion with XP SP2.
- Enabled custom MTU values under "Optimal settings."
- Added check for AOL and PPPoE "Protocol MTU" for clients that have, or have had
- Added QoS /
ToS editing to the "Advanced settings" tab.
- Added DNS error
- Added Host
Resolution Priority tweak
- Added LAN
"Request Buffer Size" tweak
- Automatic backup of related registry keys before changing any values.
- Expanded the import/export/backup capabilities.
- Added "Preferences" to the program, users can now choose URLs for the
Latency tab, as well as "maximum anticipated delay" for RWIN calculations.
- Added a preview of changes, after clicking "Apply changes" and before
they're actually applied.
- Added this documentation.
Documentation version 2.0.4 Last updated 11.20.2013
Note: some of the screenshots/information may not pertain to all OSes supported by the program.