RE: Evaluation: draft-ietf-ieprep-ets-telephony - IP Telep hony Requirements for Emergency Telecommunication Service

["Peterson, Jon" <jon.peterson@neustar.biz>]

> 
> > For an output of IEPREP, this document is mercifully short, and seems
> > almost to make sense.
> > But I can't figure out what on Earth this is supposed to mean:
> 
> > >     4) Application layer IP telephony capabilities MUST NOT
> > >     preclude the ability to do application layer accounting.
> 
> > It seems to me like a total Martian in this document. Can someone
explain?
> 
> Reading the companion general requirements doc, I think the logic is:
> 
> (1) These schemes are clearly able to be abused.
> 
> (2) Authorization can a useful tool in making these schemes 
> harder to abuse.
> 
> (3) Accounting can be a useful tool in tracking down abuse 
> after it has occurred.
> 
> As such, systems implementing these schemes should take support
authorization
> and shouldn't be designed in ways that make accounting impossible. 

Yes, that's basically right. In the idiom of the IEPREP WG,
"application-layer accounting" is a code-word for call detail records or
some sort of per-call billing invoices generated by intermediaries. It has
often been observed in IEPREP that SIP intermediaries are under no
obligation to support any transaction logging, and that it may in fact be
impossible for intermediaries to account for SIP sessions (they aren't
necessarily privy to all signaling messages - they may see set-up messages
but not tear-down messages, since they are primarily routing entities). The
strange wording above is a passive-aggressive way of phrasing the
requirement that intermediaries be notified of all signaling associated with
the call; "MUST NOT preclude" was the best compromise the working group
could reach on a message logging requirement.

> But the
> current text doesn't make this reasoning clear. Either some additional
text is
> needed or there needs to be a pointer to the discussion of these issues in
> draft-ietf-ieprep-ets-general-04.txt.
> 

I think it would be reasonable to have some more text here explaining the
motivation for this requirement, sure.

- J

> 				Ned
> 
> P.S. This is also one of those documents produced with a tool that doesn't
> includes only titles and not the file names of referenced Internet Drafts.
I
> continue to find this to be quite annoying.

Is it Word?