This sounds a bit like loose per-hop behavior. If it is decided that this is a mechanism for the WG to consider, can anything be borrowed from RSVP (and what about scaling)?What we'd need for something like this is a field in the header (well, it could be in an option but that increases overhead) that routers could look at when making routing decisions, but can be changed without breaking higher layers. Being able to change the field en route would be useful but may not be absolutely necessary.