Subject: Re: [mobile-ip] Analysis of Latency Propagation with Buffering

From: James Kempf <[email-masked]>
Date: Wed, 1 Aug 2001 13:51:13 -0700 (PDT)

Hi Charlie,

For some reason, your note was delayed and I got it after two responses.
>Hello Jim,
>
>> The concern isn't with the maximum delay added to any packet, but
>> rather the time period in which *any* traffic is buffered. The longer
>> traffic is buffered, the longer it loses its "real time" characteristic,
>             ^^^^^^^^delayed before reception

Agreed.

>> and the more likely users will perceive the converstation as stilted
>> or hear some artifact.
>
>I wanted to clarify that it isn't buffering itself that adds delay.
>A packet could be buffered AND transmitted to the mobile node at the
>same time, which then would show that buffering does not have to
>introduce any delay.  If a packet is received by the mobile node,
>then presumably it would prefer not to receive the buffered copy of
>that packet at any time in the future.
>

Well, I guess I agree, but what is the point of buffering if you
are going to transmit it or of transmitting it if you are going
to buffer it? The two options seem mutually exclusive to me.
Am I missing something?

		jak

---

From: "Charles E. Perkins" <[email-masked]>
Date: Wed, 01 Aug 2001 14:02:21 -0700

Hello Jim,

> to buffer it? The two options seem mutually exclusive to me.

The point of buffering and simultaneously transmitting is that
sometimes the mobile node might not be there to receive the transmitted
packet -- say because it moved to a new access router.  Then it would
request the previous access router to send the buffered packets that
it had not already received.

Regards,
Charlie P.