RDP: reliable data protocol

RDP: reliable data protocol

Reliable data protocol RDP is a connection-oriented transfer protocol, the main design to host monitoring applications such as download/upload and remote debugging of large quantities of data transmission effectively. RDP attempt only provide the necessary service, to operate effectively and scale small effect. Its main functions are as follows:

For each RDP transport layer connections to provide a full-duplex communication channel;

RDP try sending all user information, reliable, will send to failure if users have reported that mistake. RDP expand IP data submitted to send reliable service;

RDP try to detect and remove all the damaged and repetitive data section, it in data section head use check code and serial number realize this process;

RDP optionally provide data segment sequence to establish connections, must send in when the specified data section sequence of messages;

Respond to confirm RDP data segment, outside the sequence would release the resources to send.

Compared with TCP, RDP which support function more simple. The RDP flow control, buffer and connection management mode is is quite simple. The goal is to simply RDP effective implementation and fit for a series of application.

RDP function sets may also is to further reduce special execution subset of size.

For example, a request to other hosts download target processor possible execution a only supports the default open function and single RDP modules connected. This module may also choose not to execute the order response confirmation.

Understand in remote desktop protocol (RDP)

Remote desktop protocol based on and is T - 120 series agreement standard expansion. Many track can agreement to allow separate virtual channel for the demonstration in carrying the manuscripts data, serial communication, authorized equipment information, high encrypted data (keyboard, mouse activities) and etc. Because the core is the RDP T.S hare agreement, multiple other function expansion will be retained in RDP such as architecture support multi-drop (multilateral conversation) part of the functionality needed. More data transfer is allowed from transfers "real-time" to multiple party and not make the same data sent to each session (for example, virtual whiteboard alone) the application's data.

In Windows terminal server this the first version of but, we focus on providing reliable and fast peer-to-peer (single conversation) communications. Only a data channels will use in the initial version of the terminal server 4.0 but RDP flexibility of the function of providing adequate space, in the future products.

Microsoft decided to realize RDP connection to Windows NT terminal server of one reason is that it provides very extensible generate a lot more from the basic function. This is because RDP provide 64,000 separate channels the data transmission. But, the transmission activities using a single channel (only for keyboard, mouse and presentation manuscripts data).

Moreover, RDP designed to support many different types of network topology (such as ISDN, plants and many LAN protocols (like the IPX, NetBIOS, TCP/IP, etc.). The current version of the RDP will only run through TCP/IP, but other agreements with customer feedback in the future support may add the version.

In sending and receiving through the RDP stack the activities involved data is essentially common LAN network today seven layers of the OSI model standards are the same. From an application or services to the data is transmitted via the sectioned protocol stack downward, directional to a channel (through the MCS), encryption, packaging, plus graphic box, packing to network protocols and finally addressing and through the network sent to the client. The data the same way back only applies to reverse, and packet was removed its address, then open the decryption, informative until the data presented to applications. In the first four and seventh layer, the data is encrypted, automatic newlines and add graphic frame, directional to a channel and determine priority level between a key part of the modified protocol stack.

An application developer point is RDP, Microsoft has used in the protocol stack abstracts processing complexity. This makes them just write a clean, design perfect good behaviour 32 - a applications, then the terminal server and $its client connection realize the rest of the RDP stack responsible.

Relevant application in terminal Server on the style and content of interaction to a Windows terminal Server attention of the base structure for developing applications of detailed information, see "optimal application Windows NT Server 4.0, terminal Server edition" white paper. In multi-point communications services (MCSMUX), general meeting control (GCC), Wdtshare sys and Tdtcp. J sys is worth discussing the four components RDP stack examples. MCSmux and $GCC is the international telecommunications union (ITU) t. part of 120 series. MCS consists of two standard: t. 122, defines the multi-point services and t. 125, specified data transmission agreement. MCSMux control channels (through the predefined within the agreement of virtual channel multiplexing data) work allocation, priority level and send data section. It is essentially to extract from the perspective of the GCC multiple a single entity RDP brand fold. GCC is responsible for the management of these multiple channels. In the GCC to delete the conversation allowing creating and connected and $through the control resources provided by MCS. Each terminal server protocol (currently, support only RDP and Citrix ICA) will have the example of a protocol stack loading (wait for connection to request a protected reliably against detective program stack). Terminal server device driver coordination and management RDP agreement by activity, is composed of smaller components of the UI transmission, compression, encryption, frame and wait Wdtshare. RDP driver (sys) and transmission driver (Tdtcp sys) will be packaged together to j based protocol network protocol, TCP/IP.

The development of RDP was totally independent of this case TCP/IP stack based transmission in its. RDP, are completely independent of the transmission stack, we can will other network protocol of other transmission drivers for customer need to add their method little or no about basic agreement with major change part of growth. These are RDP performance and the main elements extendibility on the network.