Remote desktop protocol (RDP) is a secure network communications protocol from Microsoft. RDP is designed for remote management, remote access to virtual desktops, applications, and an RDP terminal server.
Features and Functions:
RDP is secure, interoperable, and enables network terminals. RDP creates secure connections between clients and servers/virtual machines, and virtual desktops are encrypted. RDP works across different Windows operating systems and devices and enables strong physical security through remote data storage.
Noteworthy properties of RDP include:
How the Remote Desktop Protocol Works:
Security:
- Bandwidth reduction
- The ability to use multiple displays
- The ability to disconnect temporarily without logging off.
- RemoteFX – virtualized GPU support
- 128-bit encryption for mouse and keyboard data. Uses RC4 encryption
- Audio redirection – audio from a remote desktop is redirected to the user’s computer.
- File system redirection – local files can be redirected to and used on a remote desktop
- Printer redirection – local printers can be used in remote desktop sessions.
- Port redirection – applications in the remote desktop session can access local ports.
- Shared clipboard between local and remote computers
- Applications on a remote desktop can be run on a local computer with Window Server 2008, a front-end IIS server can accept connections for back-end Terminal Services servers
- Transport Layer Security (TLS) support.
RDP can support up to 64,000 independent channels for data transmission. Data can be encrypted using 128-bit keys. The bandwidth reduction feature optimizes the data transfer rate in low-speed connections.
Remote client users can connect to servers and virtual machines securely over a network for communication. Different types of data are communicated through multiple, separate channels.
The RDP protocol is designed to provide remote access through port 3389. An RDP-enabled application or service packages the data that is to be transmitted, and the Microsoft Communications Service directs the data to an RDP channel. From there, the operating system encrypts the RDP data and adds it to a frame so that it can be transmitted.
The Terminal Server Device Redirector Driver handles all RDP protocol activity. This driver is made up of subcomponents such as the RDP driver (Wdtshare.sys), which handles user interfaces, transfers, encryption, compression, and framing. The transport driver (Tdtcp.sys) is responsible for packaging the protocol in such a way that allows it to be sent across a TCP/IP network.
Security:
It is generally recommended that administrators and end-users only use RDP when it is absolutely necessary. Furthermore, it should be run at the lowest level of privilege possible. When running RDP, it’s important to follow RDP's best practices to prevent security issues.