The Software Behind Connectivity
A layered view of network adapters, protocols, and the boundary between a link and an application.
A link is only one layer
A network adapter moves frames through a physical or wireless medium. Drivers expose that adapter to host networking software, while protocol stacks add addressing, routing, transport, and application semantics above it.
Descriptors and capabilities shape the path
An adapter can advertise link modes, offload features, queues, and power states. Host networking software and the driver negotiate which capabilities belong to the active interface rather than assuming every feature is always present.
Packets cross ownership boundaries
A packet can move through an application, transport protocol, network layer, link layer, driver queue, and hardware ring. Each layer owns a different representation and completion signal.
Connectivity is not one status
A visible adapter, an active link, a configured interface, and an application session describe different states. Keeping those terms separate makes network references more precise and avoids treating one observation as a complete diagnosis.
Reference facts
- Adapter role
- Expose link hardware and its capabilities to the network stack.
- State vocabulary
- Adapter visibility, link state, interface configuration, and session state differ.
Questions and answers
Does a network driver implement the entire protocol stack?
No. It represents the adapter and link boundary; protocol layers above it provide addressing, transport, and application semantics.
Why distinguish a link from an interface?
A physical or radio link can exist while the host interface has different configuration, policy, or protocol state.