Comment on VIA_RVS parameter - 5204 & 06 -bis

5206-bis specifies how to user RVS for the 'double-jump' mobility problem.

3.2.3 1) says:

1. The mobile host sending an UPDATE to the peer, and not receiving an 
ACK, MAY resend the UPDATE to a rendezvous server (RVS) of the peer, if 
such a server is known.

But it DOES know there is an RVS IF the I1 had FROM and RVS_HMAC 
parameters and it had created a VIA_RVS parameter to send in the R1.

This VIA_RVS provides the knowledge and locator of the peer's RVS.

In fact an aggressive mobility UPDATE would be sent simultaneously to 
the host and its RVS.  If the host had not moved itself, it gets both 
and drops the one from the RVS.

This comment recommends changes to 5204-bis 4.2.3 that the main goal of 
VIA_RVS is to facilitate support for the double-jump mobility problem 
and secondarily "to allow operators ...".

And to 5206-bis section 3.2.3 to use the VIA_RVS to 'know' that there is 
an RVS for the host and to optionally aggressively send HIP mobility 
UPDATES to the RVS.