What Is Tcp Auto Tuning Mean
Windows 10 Auto Tune
What Is Tcp Auto Tuning Software

Jul 08, 2018 You are correct that the TCP Window size is negotiated by the two ends of the connection. You are also correct in that limiting the TCP Window to 64KB (by turning off Auto-tuning / TCP1323 Options) also limits the bandwidth a lot, so it is counter-productive for fast internet connections. How To: Network / TCP / UDP Tuning This is a very basic step by step description of how to improve the performance networking (TCP & UDP) on Linux 2.4+ for high-bandwidth applications. These settings are especially important for GigE links. Jump to Quick Step or All The Steps.

Jan 08, 2018 Windows 10 – Auto-Tuning Disable it or not? Posted on January 8, 2018 February 22, 2018 Author MrNetTek. Window Auto-Tuning feature is said to improve the performance for programs that receive TCP data over a network. It is nothing new. It was introduced in Windows Vista and is present in Windows 10 too.

Enabling High Performance Data Transfers

System Specific Notes for System Administrators (and Privileged Users)

On this page:

These notes are intended to help users and system administrators maximize TCP/IP performance on their computer systems. They summarize all of the end-system (computer system) network tuning issues including a tutorial on TCP tuning, easy configuration checks for non-experts, and a repository of operating system specific instructions for getting the best possible network performance on these platforms

This material is currently under active revision. Please send any suggestions, additions or corrections to us at nettune@psc.edu so we can keep the information here as up-to-date as possible.

Tutorial
- Bandwidth*Delay Products (BDP)
- Buffers
- Computing the BDP
High Performance Networking Options
- Maximum Buffer Sizes on the host
- Socket Buffers sizes
- Negotiating TCP Large Windows options (RFC1323)
- TCP Selective Acknowledgments (SACK, RFC2018)
- Path MTU
Using Web Based Network Diagnostic Servers
- Quick Link: NPAD Pathdiag end system and last mile diagnostics at PSC
- Quick Link: NPAD Documentation and additional servers.
- Quick Link: SYN Test Server
- Quick Link: ORNL Bandwidth Tester
- Quick Link: ANL Network Diagnostic Tool
Detailed Procedures for System tuning and Raising network limits for:

Introduction

Today, the majority of university users have physical network connections that are at least 100 megabits per second all the way through the Internet to every important data center in the world (as well as to every other university user). For many users, that connection might be 1 gigabit per second or faster. In some countries (e.g. Korea and Japan) the same statement applies to every home connection as well: 100 Mb/s from home to all important web servers, data centers and to each other.

To put these data rates into perspective, consider this: 100 Mb/s is more than 10 megabytes in one second, or 600 megabytes (an entire CD-R image) in one minute. Clearly very few people see these data rates. However, some experts can get very high data rates (for example see the Land Speed Records). Why? The biggest strength of the Internet is the way in which the TCP/IP 'hourglass' hides the details of the network from the application and vice versa. An unfortunate but direct consequence of the hourglass is that it also hides all flaws everywhere. Network performance debugging (often euphemistically called 'TCP tuning') is extremely difficult because nearly all flaws have exactly same symptom: reduced performance. For example insufficient TCP buffer space is indistinguishable from excess packet loss (silently repaired by TCP retransmissions) because both flaws just slow the application, without any specific identifying symptoms.

Flaws fall into three broad areas: the applications themselves, the computer system (including the operating system and TCP tuning) and the network path. Each of these areas requires a very different approach to performance debugging. This page is focused on helping users and system administrators optimize the TCP/IP on their computer systems.

Applications sometimes perform poorly on long paths (even when the network is perfect) because they are not designed to fully overlap the speed of light delay to deliver the data with the processing at the end systems. It is quite difficult to write complicated applications that do this overlap properly, but it must be done for an application to perform well on a long network path. We are have developed some tools and documentation to help users and application developers to test and debug applications under these conditions.
For example secure shell and secure copy (ssh and scp) implement internal flow control using an application level mechanism that severely limits the amount of data in the network, greatly reducing the performance all but the shortest paths. PSC is now supporting a patch to ssh and scp that updates the application flow control window from the kernel buffer size. With this patch, the TCP tuning directions on this page can alleviate the dominant bottlenecks in scp. In most environments scp will run at full link rate or the CPU limit for the chosen encryption.
Network paths can be very hard to debug because TCP's ability to compensate for flaws is inversely proportional to the round trip time (RTT). So for example a flaw that will cause an application to take an extra second on a 1 millisecond path will generally cause the same application to take an extra 10 seconds on a 10 millisecond path. This 'symptom scaling' effect arises because TCP's ability to compensate for flaws is metered in round trips: if a given flaw is compensated in 50 round trips (typical for losses on a medium speed link), then a single loss affects a 1 ms path for only 50 ms, and a 10 ms path for 500 ms. Symptom scaling makes diagnosis particularly difficult, because flaws that are complete show stoppers on long paths are often be undetectable on short paths.
We have a new tool, pathdiag, which compensates for symptom scaling so that it can detect previously undetectable flaws in a local network. The basic approach is to measure the properties of a short section of the path, and extrapolate the results as though the path was extended to the full RTT with an ideal network. It then uses a TCP performance model to predict if the resulting path would perform well enough to meet the application requirements.
Pathdiag also does a complete check of the TCP options described on this page since it requires a well-tuned TCP implementation at the far end of the path. If it is available to you it is both the easiest to use and the most accurate test available. Since pathdiag requires a very short RTT the closest pathdiag server might not be close enough to you, in which case the SYN test server described below can also verify most TCP configuration options with one click.

The objectives of this page are to summarize all of the end system network tuning issues, provide easy configuration checks for non-experts, and maintain a repository of operating system specific advice and information about getting the best possible network performance on these platforms.

In the Tutorial we will briefly explain the issues and define some terms. Under High Performance Networking Options we describe each of the optional TCP features may have to configured without addressing the details of any specific operating system. The section, 'Detailed Procedures', provides step-by-step directions on making the necessary changes for several operating systems.

Note that today most TCP implementations are pretty good. The primary flaws are default configurations that are ideal for Local Area Networks (LANs) and Internet back roads: many millions of relatively low speed home users.

Tutorial

The dominant protocol used on the Internet today is TCP, a 'reliable' 'window-based' protocol. The best possible network performance is achieved when the network pipe between the sender and the receiver is kept full of data.

Bandwidth*Delay Products (BDP)

The amount of data that can be in transit in the network, termed 'Bandwidth-Delay-Product,' or BDP for short, is simply the product of the bottleneck link bandwidth and the Round Trip Time (RTT). BDP is a simple but important concept in a window based protocol such as TCP. Some of the issues discussed below arise because of the fact that the BDP of today's networks has increased way beyo

What Is Tcp Auto Tuning