OpenSFF Enclosure Specification

7. KVM Signal Routing

Enterprise Enclosures MUST implement internal signal routing to enable keyboard, video, and mouse (KVM) redirection from each compute node to the management module slot. This routing enables either direct physical access or remote IP-KVM functionality, depending on the type of Management Module installed.

The enclosure provides the physical switching infrastructure only. It does not perform console emulation or interface control — these functions are implemented by the Management Module.

7.1 Signal Multiplexing Hardware

Each compute node provides one USB 2.0 uplink and one DisplayPort output for console access. The enclosure MUST include a multiplexer subsystem to selectively route signals from one node at a time to the management module slot.

This subsystem MUST:

• Accept one USB 2.0 and one DisplayPort signal per node
• Route only the selected node’s signals to the management module
• Use electrically compliant, high-speed multiplexers for both USB and DisplayPort
• Prevent interference from non-selected nodes
• Maintain full signal integrity at USB 3.0 and DisplayPort 1.4 speeds
• Align the active signal path with the selected slot as defined in Section 5.4

Note: The enclosure does not interpret or generate control signals. It routes signals passively based on the selection logic implemented by the MM.

7.2 Slot Selection Control

Slot selection is always managed by the Management Module. Enclosures MUST NOT implement slot selection logic or override mechanisms.

Enclosures MUST expose dedicated multiplexer control lines on the management module connector, allowing the MM to select the active compute node for console redirection.

7.3 Visual Slot Identification

The management module MUST provide a visual indication of the currently selected compute node for KVM redirection. The enclosure SHALL NOT include any visual indicators or slot identification hardware.

Acceptable methods (e.g., numeric or alphanumeric displays) and required feedback behavior are detailed in Section 7.3 of the OpenSFF Management Module Specification.