Re: An opes usage question.

John G. Waclawsky wrote:

> Let's assume, for a specific example, a network allows access to premium 
> content that is billable by the number of bytes being delivered. The 
> content flows to the users from a premium content server through a pool 
> of billing gateway proxies and then proceeds to the next stage where the 
> content may be modified by other proxies for rendering on a user's 
> device (color to black/white, compressed for efficiency, adding 
> advertisements or banners etc.). If any particular flow adaptation 
> reduces the number of bytes then billing needs to be adjusted.
My first question about this specific example would be why the billing 
is done before the adaptation. If the user is billed for the adapted 
content, do the billing after the adaptation and there's no need for 
the kind of "callout server interaction" you're talking about, right?
Anyway, I believe the problem you're interested in boils down to 
tracing callout servers that did some earlier operations on the 
message. In your hypothetic example above, the adaptation server would 
have to be able to identify (the IP address?) of the billing server, 
so that it can contact the billing server, right? Could the OPES 
tracing functionality be of any help?
-Markus