Subject: RE: [Mip4] MIP RRQ Doubt

From: "Arunkumar Sivaraman" <[email-masked]>
Date: Tue, 24 Apr 2007 22:40:38 +0530

Hi Chugtu,

  After doing some tests, I found that the MN wasn't doing the
exponential back-off(2xn), before sending the RRQ. 

  The authenticated RRP from the HA, thru the FA, was arriving in abt
3secs. So, it was a bug on the MN part.

regards,
 
Arunkumar Sivaraman,
Airvana India Pvt. Ltd.,
Ph: +91-80-66189835.
 
"Truth is a bully we all pretend to like."
-----Original Message-----
From: Chugtu Manish-a22653 [mailto:[email-masked]] 
Sent: Monday, April 23, 2007 5:38 PM
To: Arunkumar Sivaraman; Kent Leung (kleung); Bjorn Andersson
Cc: [email-masked]
Subject: RE: [Mip4] MIP RRQ Doubt

Hi Arun, 

Just happened to go through this thread. I guess you have got most of
answers apart from that fact that your MN is in state of DISCONNECT as
it always happens to send a new RRQ before it gets a response for the
old one.

But I am not sure why would this happen. There sure is a timing issue
somewhere. I can understand MN missing the 1st RRP as the 2nd RRQ could
be sent in 1 second time, but the rest would be sent in 2xn time. This
is a lot of time for MN to get the RRP for the new RRQ it has sent
(Assuming HA is responding to it and its reaching the MN). So just
making sure MN is sending re-transmissions of RRQ according to RFC
should work.

Regards
Manish Chugtu

-----Original Message-----
From: Arunkumar Sivaraman [mailto:[email-masked]] 
Sent: Monday, April 23, 2007 4:45 PM
To: Kent Leung (kleung); Bjorn Andersson
Cc: [email-masked]
Subject: RE: [Mip4] MIP RRQ Doubt

Reply inline - [Arun].

Thanks,

Arun

" If you're in a vehicle going at the speed of light, what happens when
you turn on the headlights?"

-----Original Message-----
From: Kent Leung (kleung) [mailto:[email-masked]]
Sent: Mon 4/23/2007 9:54 AM
To: Arunkumar Sivaraman; Bjorn Andersson
Cc: [email-masked]
Subject: RE: [Mip4] MIP RRQ Doubt
 
Hi Arun.

It shouldn't matter if the MN rebooted or discarding RRP for some
reason.  The message flow is still the same.  I just reread your
original post and it appears to me that you are describing the same
situation of HA receiving an RRQ with Home Address field set to zero
(i.e. requesting dynamic home address) when it already has a mobility
binding for the MN.  Is this right?

[Arun]: The scenario that i've put in is different. The difference being
that in this scenario the MN thinks it hasn't registered yet with the HA
- though the HA/FA are giving a 'sucess' response to all its RRQ. The MN
is discarding this RRP because they don't match the timestamp of its
latest RRQ.

So, there's a disconnect in the state of a call between MN & FA/HA. MN
thinks for some reason it keeps getting RRP of expired RRQ(s), whereas
the HA/FA already have the call as being in a registered state and
therefore treat further RRQ(s) from the MN as being re-registrations.

I hope I have been able to get my point across :).
 
This is what case #7 in the table in section 6.1 covers.  You had asked
if the HA should reply with same Home Address or a new IP address.  The
draft says HA assigns the same Home Address to the MN.  The scenario in
the draft is really just an example of when this event happens. 
 
Kent 

-----Original Message-----
From: Arunkumar Sivaraman [mailto:[email-masked]] 
Sent: Saturday, April 21, 2007 12:53 AM
To: Kent Leung (kleung); Bjorn Andersson
Cc: [email-masked]
Subject: RE: [Mip4] MIP RRQ Doubt

Kent,
  I went through the draft & also the particular section & case,
referred in your last mail. The situation i've put in my mail isn't same
as case #7. In the scenario i've given, the MN hasn't rebooted but is
discarding the RRP(s) from the FA since it has waited for a reasonable
time' - as per rfc 3344, for a RRP. So, if the MN is using the timestamp
method to send new registration requests, then it will keep discarding
the RRP(s) - even if the FA/HA keeps accepting each of its RRQ(s). 

  Can we have this as a case scenario in the draft?

  But it still begs the question, if a MN was doing this again & again,
shouldn't the FA/HA  remove its binding after say 'n' such similar
RRQ(s). 

All,

  On a related note, any reason why there isn't a specific time for a MN
to wait for a RRP, before sending new RRQ(s) using the timestamp method.

Thanks,

Arun

" If you're in a vehicle going at the speed of light, what happens when
you turn on the headlights?"
<snip>

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