> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.nvidia.com/rms/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/rms/_mcp/server.

# External View

RMS is structured as thin, protocol-specific gateways over an orchestration
layer. A gRPC gateway translates requests into calls on the **orchestrator**,
which owns the rack map and the job tracker. **Rack** implementations create
**node** objects, and node implementations hide the protocol-specific I/O behind
a common trait. Nodes are pure async I/O - they have no knowledge of job tracking
or scheduling.

The service is built on **tokio** for async I/O, **tonic** for gRPC, and
trait-based polymorphism for extensibility across node and rack types.

For how these layers fit together internally, see [Internal View](/rms/documentation/architecture/internal-view).

## Northbound and southbound connections

RMS has one **northbound** (incoming client) interface - the `RackManager` gRPC
API - and several **southbound** (outgoing) interfaces it uses to reach hardware.

![RMS northbound and southbound connections](https://fdr-prod-docs-files-public.s3.us-east-1.amazonaws.com/nvidia-rms.docs.buildwithfern.com/5aad3989fd01fc204d24638fd3a037b8790b73d2c97150f3d476bdc8b7e4c01b/_dot_dot_/docs/diagrams/northbound-southbound.svg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6KXJSKKNFOCF7G4B%2F20260827%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20260827T183431Z&X-Amz-Expires=604800&X-Amz-Signature=d363c1007d15ca40ba78efd9eda81c39e8c693f78bdeb347ebdd1fe8cd0a88e0&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

| Direction | Peer | Protocol(s) | Notes |
| --- | --- | --- | --- |
| Northbound | gRPC clients | gRPC over mTLS (TLS 1.3, rustls) | Single `RackManager` service; plaintext only in insecure dev mode. |
| Northbound | Prometheus | HTTP(S) `/metrics` | Independent listener; optional TLS reusing the gRPC server cert. |
| Southbound | Compute tray & power-shelf BMC | Redfish over HTTPS | Power, reset, device info, firmware inventory, multipart firmware upload. |
| Southbound | NVSwitch tray (NVUE/NVOS) | NVUE REST over HTTPS, SSH, SFTP | Switch firmware, system images, passwords, certificates, config. SFTP uploads switch OS images. |
| Southbound | NVSwitch tray (NMX-C) | NMX-C gRPC, gNMI | Scale-up fabric manager state and telemetry-interface control. |