Re: Draft on Callout Protocol Requirements (fwd)

Volker, 
        Here is my comments about section 3.2.4.
        " If only one approach SHOULD be supported by a callout protocol,
the penalty for not using the optimal approach MUST be considered. .... "

        I am thinking that the intermediary can maintain a small cache to
record the specfic preview size of each of those services. As such, the
penalty of both approaches will not be a big deal here. (I assume the
preview size required by each service is fixed.) 
        

-Weisong