The tcp ip stack in the Windows system

Today we will talk about what the TCP / IP protocol stack is and what its parameters can be customized. It's hard to imagine a full-fledged modern computer that does not have access to the global Internet. Just run the connection shortcut - and virtually all existing resources are available. However, sometimes even a label is not needed. In any case, the interaction of the network interface with the Global Network provides a stack of TCP / IP protocols.

Now users of personal computers are no longer surprised by the new operating systems, because the gap between the outputs of new versions is constantly decreasing. This is observed in all popular systems: Windows from Microsoft, immortal Linux, Apple OC (Apple), etc. The reason is simple: developers are trying to keep up with the progress (take, for example, the same mobile devices to access the Internet), so forced Update the product line. But not all end users install new versions of operating systems. Indeed, if everything works ...

How does the TCP / IP protocol stack relate to all of the above? Imagine a situation: there are two identical computers, one of which has a Windows system installed in 1998, and on the other - the latest version of Linux. It is easy to see that the speed (and other parameters) of working with the Network will be different. The reason is the TCP / IP protocol stack, its implementation in each case. Often it is enough to install a new version of the system in order to get the performance increase of the network interface.

As already mentioned, the TCP / IP stack provides the ability to communicate connected to the network of computing devices. Protocols are divided into 4 conditional steps. The lowest is the base, it is represented by physical interfaces, for example, Ethernet. The next (third) stage is the transfer of the datagram through the local networks. The second is the main one, it is at this stage that the UDP and TCP protocols are functioning. Finally, the uppermost step is applied, FTP and SMTP are bright examples. The existing TCP / IP model was proposed more than 20 years ago for the ARPAnet network. Soon this protocol was implemented in Unix systems (the heart of modern Linux). Not surprisingly, the Internet functions on the TCP / IP stack.

In Windows family systems, the stack settings are located in one of the registry branches responsible for Tcpip. All parameters are of type DWORD. One of the most important is the duration of the "life" of the data packets, DefaultTTL (Time-to-Live). Each unit points to a routing device that processes the packet. If the path of these devices is greater than the value of TTL, the packet is destroyed.

When set to one, DisableTaskOffload disables the use of the network card co-processor. If there is a similar solution on the card, it makes sense to change the parameter to 0.

EnablePMTUDiscovery uses the mechanism to determine the optimal MTU packet size. If the parameter is disabled (0), the default value is 576 bytes.

A rather curious point SackOpts first appeared in Windows XP. Its inclusion (1) allows the system to re-send only lost packets, and not the entire message, if necessary.

KeepAliveInterval indicates the amount of delay between sending test packets that allow you to check the connection activity. If you receive a response from the server, the test packets are not sent until the time specified in KeepAliveInterval is reached. Usually this value is 1000.

The MTU indicates the size of the transmitted data block. Has a direct effect on the performance of the connection. To a large extent depends on the speed of the connection (cable channel, telephone line, etc.).

All these parameters can be manually configured, taking into account the characteristics of the existing connection. In addition, many specialized programs (tweakers) allow you to simplify the configuration process. Please note that in some cases, the degradation of the Network mode is possible.