Re: DoCoMo Implementation Issues with CTP

> 
> Hello Raghu,
> 
> 
> Raghu wrote:
> 
> > >
> > > - When both IPv4 and IPv6 addresses are used in CTD,
> > >  "Processing the address of the opposite
> > > version in the stack is complicated. " Could you elaborate on
> > > this ? I can see that once IP (v4 or v6) stack demultiplexes the
> > > packet to belong to a CTP client, it would just forward the block
> > > to a CTP module (a daemon for instance), which could then
> > > process contexts associated with both the addresses.
> > >
> > IP Version flag in the draft indicates whether the IP Version
> > can be either IPv4 or IPv6 or both(IPv4 & IPv6).
> > When MN is assigned both IPv4 & IPv6 addresses,
> > it is assumed that AR also has both IPv4 & IPv6 addresses.
> > When MN moves, sending two CT messages for the same MN
> > is unnecessary. Hence to avoid this, either IP version flag
> >
> 
> hmm.. This is perhaps a misunderstanding.
> The `V' bits indicate whether contexts corresponding to
> both IPv4 and IPv6 addresses (as well as the addresses
> themselves) are present. The (P)CTD message itself
> can be either IPv4 or IPv6. You may observe that the
> Source and Destination IP addresses for all the messages
> are absent. I cannot say this is intentional, but the result is
> that the messages themselves can be carried in IPv4 or IPv6
> packets.
> 
> 
> > should not support both IPv4 & IPv6 at the same time or
> > the draft should mention, which IP version to take precedence.
> >
> 
> Hopefully, the above explanation clarifies..(i.e., IP version of
> the packets carrying CTP messages is independent of the
> `V' bits).
> 
I understand your point, but
I request you to explain how the implementation should be 
in the following scenario ?

When MN moves, MN sends CTAR to nAR,
nAR needs to extract IP information from CTAR and send a CTREQ to oAR.
When both(IPv4 & IPv6) are present in CTAR, What is the behaviour of nAR ?


regards,
Raghu