What do we call interaction between different OSI layers on the same device?

The interaction between different OSI layers on the same device is referred to as adjacent-layer interaction. This is because each layer in the OSI model can only directly interact with the layers immediately above and below it. For example, when a packet is transmitted from the transport layer down to the network layer, or when data is requested from the application layer down to the transport layer, this represents interaction between adjacent layers.

Understanding this concept is crucial in networking, as it defines how data is encapsulated and how the layers work together to enable communication. This alignment allows for a structured approach to troubleshooting and managing network communication, emphasizing that issues can often arise due to interruptions or misconfigurations at these layer boundaries.

Other terms mentioned, such as same-layer interaction or cross-layer interaction, refer to interactions that do not precisely align with the OSI model’s layering system. Same-layer interaction typically involves communication between devices at the same layer across a network, while cross-layer interaction implies that two non-adjacent layers are engaging, which goes beyond the direct relationship recognized in the OSI model's design.