What is Remote Desktop Protocol?
The Remote Desktop Protocol (RDP) is a technical standard for using a desktop computer remotely. Remote desktop software can use several different protocols including Independent Computing Architecture (ICA), Virtual Network Computing (VNC), and RDP. RDP, the most commonly used protocol, was initially released by Microsoft and is available for most Windows operating systems and with Mac OS, as well. When users use RDP, mouse movements and keyboards strokes are transmitted directly to a desktop in a different location. RDP users can access their desktop, open and edit files, and use applications as if they were sitting at their desktop computer.
RDP works by linking local and remote devices. The RDP port opens a secure network channel where data can be sent back and forth between the connected machines, allowing the data such as mouse movements, keystrokes, and the desktop display to be transferred over this channel trough TCP/IP. RDP encrypts the public internet connect in order to protect the transmitted data. Connection between the server and the client occurs in nine stages1:
- Connection initiation. Establishes the link and begins encryption for security.
- Basic handshake. Exchanges basic settings and core data.
- Channel connection. Opens the channels to begin communication.
- Security initiation. Creates the encryption key the endpoints will share.
- Secure settings exchange. Sends sensitive data like passwords now that encryption is in place.
- Licensing. Authenticates the client.
- Capabilities exchange. Transmits more general information.
- Connection finalization. Ensures synchronization and the final connection.
- Data exchange. Refers to the actual transmission of user inputs and remote outputs between the computers.
Common uses for RDP include:
Remote work. Employees working away from the office can use RDP to access their work desktops, which improves the productivity and flexibility of the organization.
Help desk. RDP allows IT personnel to troubleshoot and solve software problems by in-house IT staff or outsourced IT operations, without requiring an in-person visit. RDP may save time for everyone involved, as technicians at help desks, call centers, or service desks can troubleshoot directly through RDP without having to provide verbal instructions to the end user.
Sharing. RDP provides employees, contractors, vendors, or auditors access to a desktop offering a similar user experience as one would expect in an office. Through RDP they may have access to local resources, applications, or graphic user experiences.
Printing. Print jobs can be sent to a local printer from a remote desktop connection.
1 CrowdStrike, 2022, “Remote Desk Protocol”