Thursday, April 28, 2011

Re: [Geopriv] [geopriv] #49: Review of Deref Protocol document

> A location URI can be acquired using a location configuration protocol, such as HTTP-Enabled Location Delivery (HELD) [RFC5985] or the Dynamic Host Configuration Protocol (DHCP) location URI option [I-D.ietf-geopriv-dhcp-lbyr-uri-option]. 
>
> > [BA] So how does the dereferencer know that HELD is to be used to
> > dereference rather than generic HTTP??
>
> They might use the content type of the response entity. The draft now makes this observation in S4.2, along with the other GET semantics.
>
> A Location Recipient MAY infer from a response containing the HELD content type, "application/held+xml", that a URI references a resource that supports HELD.

[BA] Thanks.  

Some questions:

a. In the above are you referring to the response in the original HELD exchange, or to a response to a dereference request (e.g. a GET or POST)?  
b. If this would apply to a dereference using a GET, is the implication that a HELD-capable client might subsequently choose to upgrade its requests to HELD (for error resilience or other reasons?)
c.. Should a de-reference request using GET specify the content types it prefers/is prepared to handle in the GET via an Accept: header?  
d. If so, are there content types that could be provided in the de-reference request other than "application/held+xml"? (e.g. to indicate whether the de-reference requester does/doesn't support HELD).    
e. Should a LIS be prepared to support content types other than "application/held+xml" in a request Accept: header?