Layers

Where it sits

Classic OSI plus OT and telecom specialty lanes used across the catalog.

Physical L1

Signals, media, bit timing, connectors.

45 protocols

Data Link L2

Frames, MACs, arbitration, link control.

52 protocols

Network L3

Addressing and routing across hops.

21 protocols

Transport L4

End-to-end streams, reliability, ports.

27 protocols

Session L5

Dialogs, call state, session control.

16 protocols

Presentation L6

Encoding, codecs, serialization.

9 protocols

Application L7

User-facing protocol semantics.

73 protocols

OT / Fieldbus

Industrial and operational technology stacks.

5 protocols

Telecom

SS7, ISDN, VoIP signaling families.

31 protocols