Modified the start of the example (Section 3.10, new section number) to be clear
that it covers just a single segment of the path. Revised text:

   Consider the case of an RSVP-like signalling application which
   allocates resources for a single unicast flow.  In general,
   signalling can take place along the entire end-to-end path (between
   flow source and destination), but the role of GIST is only to
   transfer signalling messages over a single segment of the path,
   between neighbouring resource-capable nodes.  Basic GIST operation is
   the same, whether it involves the endpoints or only interior nodes:
   in either case, GIST is triggered by a request from a local
   signalling application.  The example here describes how GIST
   transfers messages between two adjacent peers along the path, GN1 and
   GN2 (see Figure 1 in Section 2).  We take up the story at the point
   where a message is being processed above the GIST layer by the
   signalling application in GN1.

From Lisa Dusseault:

Section 3.7: 
Where did the NSLP get the message from
-- I thought the NSLP would likely create the new message, not process it?