Transfer frames, in both directions, plus reliable delivery and security on top of them.
| Protocol | Standard | Package | |
|---|---|---|---|
| TM Space Data Link Protocol | CCSDS 132.0-B-3 | pkg/tmdl | Conformance |
| TC Space Data Link Protocol | CCSDS 232.0-B-4 | pkg/tcdl | Conformance |
| AOS Space Data Link Protocol | CCSDS 732.0-B-4 | pkg/aos | Conformance |
| Unified Space Data Link Protocol | CCSDS 732.1-B-3 | pkg/usdl | Conformance |
| Proximity-1 Data Link Layer | CCSDS 211.0-B-6 | pkg/pxdl | Conformance |
| COP-1 | CCSDS 232.1-B-2 | pkg/cop | Conformance |
| Space Data Link Security | CCSDS 355.0-B-2 | pkg/sdls | Conformance |