Re: Fw: [RPRWG] CRC check in each node?
hello Pankaj
Since CRC can be used for identifying if there is a problem in the link
(i.e., signal degradation causing the CRC error), it is desirable to only
record this data in the first node that sees this CRC error (so that one
can see that there may be a fault in the link). If every node that sees the
same CRC error accumulate such data, how are you going to identify which
one is the link that generated the error? The bit set is used (as I heard
from the 802.5 folks) to say that the CRC error was already detected
upstream and there is no need to use that information on performance
monitoring of downstream nodes...
Does it make sense?
Angela
Pankaj K Jha <pkj@xxxxxxxxxxx> on 07/02/2001 11:42:04 AM
To: RDLove <rdlove@xxxxxxxxx>
cc: "Angela T. Faber" <afaber@xxxxxxxxxxxxx>, "ieee 802.17 list"
<stds-802-17@xxxxxxxx> (bcc: Angela T. Faber/Telcordia)
Subject: Re: Fw: [RPRWG] CRC check in each node?
I've one doubt I'd like to clarify. If it is only for the local station to
record statistics, why would it have to set a bit in the packet to do so?
It
already knows there is a CRC error and it can update its statistics
locally. As
far as other other downstream nodes are concerned, they too will find the
CRC
errors during reception because they'll be checking for CRC errors anyway.
What
exactly does the bit setting help in? It doesn't help in node
identification in
a series of nodes. Please advise.
Regards,.
Pankaj
RDLove wrote:
> Pankaj, the reason to set a bit when a station sees a CRC error, is so
that
> the station that first sees the error can record the "error created"
event.
> It is that station, and not the destination station with the information
> available for transmitting to a station that gathers statistics.
>
> Best regards,
>
> Robert D. Love
> Chair, Resilient Packet Ring Alliance
> President, LAN Connect Consultants
> 7105 Leveret Circle Raleigh, NC 27615
> Phone: 919 848-6773 Mobile: 919 810-7816
> email: rdlove@xxxxxxxx Fax: 208 978-1187