Proposal for WS-Policy assertions

Gilbert and I took an action to propose some assertions for declaring  
WS-Addr requirements/capabilities in WS-Policy. After a bit of  
discussion we came up with the following three assertions:

(i) <wsaw:AddressingRequired/> - the endpoint requires WS-Addressing,  
optionality can be conveyed using WS-Policy constructs.

(ii) <wsaw:AnonymousReplies/> - the endpoint can send replies using  
WS-A anonymous; the endpoint can't send to anon if not present.

(iii) <wsaw:NonAnonymousReplies/> - the endpoint can send replies  
using other addresses; the endpoint can't send to other addresses if  
not present (unless some other assertion adds a class of supported  
addresses).

Assertion (iii) is deliberately vague, its presence means that a non- 
anon address might work but doesn't constrain what such an address  
might look like - a receiver can still reject an address that it  
doesn't grok or that requires a binding it doesn't support. The WG  
decided against specifying things like available response bindings so  
I think this is in line with that decision.

Here are some examples:

<wsp:Policy>
   <wsaw:AddressingRequired/>
   <wsaw:AnonymousReplies/>
</wsp:Policy>

Means that addressing is required and only anonymous replies are
supported.

<wsp:Policy>
   <wsaw:AddressingRequired/>
   <wsaw:NonAnonymousReplies/>
</wsp:Policy>

Means that addressing is required and only non-anonymous replies are
supported.

<wsp:Policy>
   <wsaw:AddressingRequired/>
   <wsaw:AnonymousReplies/>
   <wsaw:NonAnonymousReplies/>
</wsp:Policy>

Means that addressing is required and both anonymous and non-anonymous
replies are supported.

<wsp:Policy>
   <wsaw:AddressingRequired>
</wsp:Policy>

Wouldn't be too useful for anything other than a one-way message  
since neither anonymous nor non-anonymouse replies are supported.

<wsp:Policy>
   <wsaw:AddressingRequired/>
   <wsaw:AnonymousReplies/>
   <wsfoo:AnonReplies/>
</wsp:Policy>

Means that addressing is required and that anon replies as defined by  
WS-Addr or WS-Foo are supported.

Marc.

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Marc Hadley <marc.hadley at sun.com>
CTO Office, Sun Microsystems.