RE: Fw: [RPRWG] CRC check in each node?
Reuven,
I too is of the same opinion -- header hec for pass-though forwarding or
drop decision; application level CRC or whatever the application desires.
>> variable sized packets & CRC
yes. However this could be still be done at the application level for
the specifc application.
Some applications that can tolerate higher bit errors they can consume the
packet without crc.
-Kumar
-----Original Message-----
From: Devendra Tripathi [mailto:tripathi@xxxxxxxxxxxxx]
Sent: Tuesday, July 03, 2001 2:01 PM
To: Reuven Zeitak; ieee 802.17 list
Subject: RE: Fw: [RPRWG] CRC check in each node?
I think, in variable sized packet based network, CRC plays a very important
role. It may be noted that at TCP level, all we have is checksum.
Regards,
Devendra Tripathi
CoVisible Solutions Inc.
(formerly VidyaWeb, Inc)
Pune, India
Tel: +91-20-433-1362
> -----Original Message-----
> From: owner-stds-802-17@xxxxxxxxxxxxxxxxxx
> [mailto:owner-stds-802-17@xxxxxxxxxxxxxxxxxx]On Behalf Of Reuven Zeitak
> Sent: Monday, July 02, 2001 10:47 PM
> To: ieee 802.17 list
> Subject: RE: Fw: [RPRWG] CRC check in each node?
>
>
>
> Hi Everybody,
>
> I have been following this interesting thread. I want
> to rock the boat a bit here to make sure all points have
> been considered:
> Question: Is a CRC on data really what we want?
>
> Consider:
>
> ATM only has a HEC and does not protect data,
> it is left to the application.
>
> In some sense RPR is just an encapsulation of user data
> and has to be agnostic to the data content. As it was pointed
> out here, Users may want to keep on getting the data even if
> there are link errors. Maybe the application has a sophisticated error
> recovery method. Maybe it has none. Is it the RPR layer's job to
> provide the application an error indication?
>
> We clearly need some kind of BER measure (in the SONET jargon)
> to verify if the link is alive. Isnt the HEC good enough for that?
> HEC errors are to be discarded at the next node anyway, so that
> there is no issue of double counting an error.
>
> reuven
>
> ------------------------------------------------------------------
> ----------
> -----------------------------
> Reuven Zeitak PhD
>
> Modeling And Algorithms
> Native Networks
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>
> The Native Way = Ethernet Simplicity + SONET Reliability
>
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