The best adapter is the one you do not have to implement. The end. Ah, if only we could get rid of them so easily. Requirements for an adapter within a domain usually signify that something in your service inventory went wrong and you overlooked the discrepancies in your data models, formats, and/or messaging/transport protocols. Regarding protocols, you could actually anticipate that a single protocol would not be enough and the Dual Protocol SOA Pattern (http://soapatterns.org/design_patterns/dual_protocols) can be justified in the cases explained next.
Your service activities on both the north and south sides are the canonical SOAP over HTTP, but between servers, handling every individual layer of your SOA frameworks (
EBS<->EBS), you would like to have something faster, without XML processing overhead. In this case, the RMI-type protocols could be the optimal choice, such as