Re: DoCoMo Implementation Issues with CTP

> > > Why is it necessary to know PAR's IP when the contexts
> > > are already there ?
> > For two reasons,
> > 1. To avoid picking up of any Stale contexts due to frequent moving of
MN.
> >
>
> I cannot readily figure out how PAR's IP helps here..
>
For example,
Consider 3 ARs  A, B & C
MN moves from A to B, so A sends PCTD to B.
But MN never sends CTAR to B but instead moves to C
and sends CTAR to C with pAR as A.
Now C gets the contexts from A and MN stays here
for a short time and now moves back to A and immediately to B.
Again A sends PCTD to B.
When MN sends a CTAR to B, which PCTD should be used ?

Also incase of Mobile IP where MN IP doesnot change,
and MN moves from A to B (A sends PCTD to B,
MN doesnot send CTAR) instead moves to C then
to B(C sends PCTD to B, MN sends CTAR to B),
which PCTD should B use ?

>
> > 2. Security.
> >
>
> If the token matches, the MN must have had an SA
> with PAR.
>
Probably security is not a major concern as
CTP assumes prior SA (like IPSEC) between ARs to transfer CTP.

regards,
Raghu