Subject: RE: sending null register msgs in register State machine

From: Bill Fenner <[email-masked]>
Date: Wed, 8 Aug 2001 03:11:42 -0700

>If you follow the text in the new 
>draft - 'subtracting off register_probe_time is a bit unnecessary .......and
>is kept for compatability'is not correct. 

In what way is it not correct?  As long as you actually follow the DR's
Register state machine, it doesn't really matter what the initial value
of the RegStop timer is; the DR will still send a Null Register and
wait "probe time" seconds before starting to send new encapsulated data.

>Should I assume that the authors are going to remove this para in the draft

The compatability issue here is maybe a bit silly - it's just the question
of what the RP actually expects when it sends a Register-Stop (and whether or
not it matters).  In RFC 2362, the DR would wait 
Register_Suppression_Time - Register_Probe_Time before sending a
null-register; when we introduced the randomization to prevent
synchronization, the Register_Probe_Time is presumably dwarfed by
the randomization, so as the spec says, it's not clear that it's
necessary.  Does the list have any opinions on removing it?

(If we remove the subtraction, the average time that a DR will suppress
registers will be Register_Suppression_Time + Register_Probe_Time
instead of Register_Suppression_Time.  It will continue to wait
Register_Probe_Time after sending a null register to elicit a response
from the RP.).

  Bill

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From: Bill Fenner <[email-masked]>
Date: Wed, 8 Aug 2001 03:16:33 -0700

I wrote:
>when we introduced the randomization to prevent synchronization

I take it back -- RFC 2362 had the randomization (I read the wrong
part).  So, removing the subtraction of the probe time would simply
change the average percieved quiet time by the RP from
Register_Suppression_Time to Register_Suppression_Time + Register_Probe_Time.
Since the RP just expects the DR to shut up for "a while" when it
sends a Register-Stop, it doesn't matter at all one way or the other.

The subtraction of the probe time in the new spec is compatability with
something that I suspect isn't important to be compatible with.  Perhaps
the best thing is to simply remove it.

  Bill