In this article, we will learn how to adjust through RFC1323 protocol to Windows XP registry parameters, RFC 1323 protocol is TCP high performance extensions - in order to adjust, improve and optimize the network speed and throughput. This technique can save you download the software, programs or even purchase additional network equipment or hardware investment required.
Windows XP contains several dynamically affect the performance of the registry parameters - a setting which is used to deal with RFC 1323, that is, high-performance TCP extensions.
Cited in RFC 1323 TCP window is the receive window - TCP-chip cache memory to reach space, unless (a) the incoming data packet and then they set up Push tag is issued to the application immediately, or (b) to receive it applications to access its data cache.
In the TCP handshake process, both based on TCP connection would tell each other their receive buffer size. This is included in the TCP header inside the Window Size field. The typical value of this field is 65,535 (it was a 2-byte length field, it said 65,535 is the maximum). This indicates that, if necessary, send handshake packets equipment 65,535 bytes of space available for storing incoming data. Note If a TCP node from the initial communication sent in the TCP handshake packets using TCP Window Scale option, then the XP system by default will use Window Scaling. This means that if your XP device as a server (response to the initial TCP handshake packets) to use, you will use Window Scaling. If your XP device is a client (for example, you used to connect an HTTP server or mail server), you will not use Window Scaling.
If a host buffer space in the file transfer time runs out, it must return to send a field value contains the Window = 0 packets. TCP node to stop sending data until a window update (Window Update) packets sent over. A window update packet is a simple ACK packet, the size of its window with a non 0 value. When the window after the update process, the data stream may be re-continue. Figure 1 shows the data flow has stopped, because a host proclaimed the window 0 (Window Zero) situation.
Figure 1: The receiver sends the host with the TCP Window Size field to 0 to stop the packet data transmission, because the host has been the lack of available buffer space of the 65,535 of the window size value in the current faster links and more thick pipe and a larger file transfer is already not enough. Window 0 state to promote the creation of Window Scaling, which is defined in RFC 1323 in. In the TCP handshake process, if both sides are added to TCP Window Scale option header, it will be to support window scaling. Both sides must contain a Window Scale option value, so that both sides can use this function. Window Scale option defines the window size required for use in determining the multiplication factor, shown in Figure 2.
Figure 2: The Host in its TCP handshake packet declares Window Scale by a factor of 2. The size factor will actually receive window size increased to 262,140 bytes window size (Window Scale) value is the value of a power operation. Example, Window Scale Set to 0 to Window Scale field value will be multiplied by 1 (do not change size, it just allows the other party can use window scaling). If the Window Scale value of 1 means that you should be good window size field value to 2.
For example, if the size you are downloading more than 75MB (I usually used to test an HTTP file transfer based on the appropriate size of the value) of the Open Office Suite. If you do not activate the Window Scaling, but they do want you to have a decent throughput ratio, you may receive window size because only 65,535 receive buffer space, blocking the download process. Window Scaling and size adjustment factor set to 4, which will provide a 262,140-byte receive buffer space. To open the Window Scale setting (and do not open the timestamp option, and this I will be described in another article), the tcp1323opts the value to 1.
Tcp1323Opts
Key: TcpipParameters
Value Type: REG_DWORD - number (flags)
Valid Range: 0, 1, 2, 3
0 (disable RFC 1323 options) (disable RFC 1323 options)
1 (window scaling enabled only) (window scaling enabled only)
2 (timestamps enabled only) (timestamps enabled only)
3 (both options enabled) (opening of window scaling and timestamp)
Default: no value. The default behavior is this: When the TCP connection initialization not to use the time stamp (Timestamp) and the window size (Window Scale) option, but if the node is initialized to communicate TCP SYN film included in them, on the use of timestamp and window size (Window Scale) option.
Description: This parameter controls the RFC 1323 time stamps and window size of TCP options to use. Explicitly set the time stamps and window scaling is controlled by bit tag. Bit 0 controls window size, bit 1 controls timestamps.
Note: any changes must be selected prior to the baseline network traffic. This allows you to verify your changes made on the network communication can have a positive effect. More on Network baseline, TCP / IP communication analysis and troubleshooting information, please visit www.wiresharkU.com.
About the author:
Laura Chappell is the Wireshark University and the founder of Protocol Analysis Institute. She is a first-class speaker and involved in network communication, analysis, and security industries and many writers. She has thousands of network administrators, State and Federal law officers, judicial members, engineers, technicians and developers to provide training. Chappell is the High Technology Crime Investigation Association (HTCIA) one of the members, FBI Infragard key member of the organization, and the Institute for Electrical and Electronic Engineers (IEEE) since 1989, the Associate Members. She set a sense of humor, personal experience, passion, and lucid presentation of various characteristics make her a division of the General Assembly high-level industry speakers, including: Microsoft TechEd, HP TechForum, HTCIA International Conference, Congress Netherlands, Electronic Crime Task Force Quarterly Meetings and Novell BrainShare Conference.