Attached is a proposal how to describe serial compound links, thus how to describe the individual segments in a path. The example is given as a picture and in XML. Observe that only the "link" concept is used; "path" is removed from NML (the reason is that a path can be extended and form a link in an even larger path). The example uses two distinct methods to stitch paths together: - Using ports (if the sink of link A is port X, and the source of link B is also port X, you know that links A and B are connected in series) - Using explicit ordering (order="1", order="2"). This is done on purpose. If all port information is known, the ordering can be determined using the first method. However, not all information may be known. For example, a domain may want to say that a segment is part of a path, without knowing details about the other segments (eg. segment BC may be provided by a different domain): <nml:link type="link" nm:id="urn:ogf:network:example.net:pathAC"> <nml:relation type="serialcompound" cl:type="partial"> <nml:segment nm:idRef="urn:ogf:network:example.net:segmentAB"/> </nml:relation> </nml:link> For now, I picked a simple method to specify ordering, using a simply number ("order"), and a total count ("count") so I know the order, and that it is a complete list. <nml:link type="link" nm:id="..."> <nml:relation type="serialcompound" cl:count="3"> <nml:segment nm:idRef="..." cl:order="1"/> <nml:segment nm:idRef="..." cl:order="2"/> <nml:segment nm:idRef="..." cl:order="3"/> </nml:relation> </nml:link> I choose some arbitrary names for some attributes; I'm happy to discuss that in another thread. Regards, Freek