Services will be addressed implicitly (via logical names) as well as explicitly (endpoint references, or EPRs). Sending and receiving of messages require styles such as those typified in WSA, e.g., wsa:To, wsa:ReplyTo and wsa:From. Rather than re-inventing the wheel, we may as well use the WS-Addressing EPR format for service identification.

? Logical service names require mapping to address(-es) via name service/registry. A federated approach will be used, to allow registries to span multiple repositories and implementations.
? Address-based approach based on the wsa:EPR format.

The addressing scheme should not be tied to a specific delivery pattern or implementation.

Logical names will be resolved via the repository; this may also be used to provide the basis of the mediation/indirection mechanism of traditional ESBs: for example, client talks to service A via a logical name LogicalAName; the mapping of LogicalAName to physical EPR produces mediation service EPR with ReferenceParameter including service A EPR (or some means for the mediation service to determine the ultimate destination service EPR).

The current requirements for an EPR can be summarised in the interface below.

interface EPR
{
public void setTo (URI uri);
public URI getTo ();
public void setFrom (URI uri);
public URI getFrom ();
public void setReplyTo (URI uri);
public URI getReplyTo ();
public void setFaultTo (URI uri);
public URI getFaultTo ();
public void setAction (URI uri);
public URI getAction ();
public void setMessageID (URI uri);
public URI getMessageID ();
public void setMetaData (MetaData md);
public MetaData getMetaData ();
public void addReferenceParameter (...);
}