Using middleware technologies in modern distributed embedded environments, one is often faced with connecting incompatible transport media to the communication stack, especially in the military domain. In case of CORBA, natively unsupported media can be plugged in via ESIOP, integrating it into the middleware. This approach tightly couples media to middleware and tends to be unportable between middleware technologies. In contrast, this paper suggests transport abstraction by providing IPv6 adapters for each medium, exploiting the predominance of IP support in middleware and existing adapters. Apart from the flexibility gained compared to transport integration, the proof-of-concept implementations of both approaches, based on CORBA and CAN, show an up to a tenfold improvement in invocation time over integration. Transport abstraction not only reduces the problem to adapting media to IPv6, but also allows transport media independent substitution of middleware and vice versa.