Protocol ossification
= Protocol ossification
<Protocol ossification> occurs when deployed implementations or intermediaries make established behaviour difficult to change, for example by rejecting an unfamiliar transport format or assuming fields will never evolve. <Endpoint> support alone may then be insufficient for deployment over real paths.<Report from the IAB Workshop on Stack Evolution in a Middlebox Internet (RFC 7663)>[§§2–5: interface and middlebox constraints on evolution]{ref}