A component of the Microsoft Windows NT operating system that supports the Workstation service by enabling access to shared folders and printers using standard Win32 network application programming interfaces (APIs).
When an application tries to access a shared resource using a Universal Naming Convention (UNC) path, the request first goes to the I/O Manager, which forwards it to the Multiple UNC Provider (MUP). The MUP then queries the installed redirectors to determine which one can access the shared resource. These queries are passed to each redirector through a provider dynamic-link library (DLL) that is designed to communicate with that vendor’s redirector but presents a common programming interface to the multiple provider router (MPR). Once the appropriate redirector has been selected, the MPR forwards the request to the redirector.