Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: (2) [802.3ae] WIS Test Pattern Error Counts


The fact that the B1/B2/B3 error checking processes are used
to report bit errors does not imply that a test pattern checker
function is not required, or that the test pattern checker will
not report bit errors. The WIS clause specifies functionality
and not implementation. The test pattern checker functionality
is required to be present, even though an actual implementation
of the WIS would most probably just re-use all of the Receive
datapath mechanisms needed for normal operation, and add simple
CID pattern processing logic to this. In fact, the last paragraph
plus the last Note in subclause tries to bring this out.

Hope this answers your question.

Best regards,

- Tom Alexander
WIS Scribe

-----Original Message-----
From: Nepple, Bruce [mailto:bnepple@xxxxxxxxxxxxxxxxxxx]
Sent: Monday, September 17, 2001 4:53 PM
To: stds-802-3-hssg@xxxxxxxx
Subject: RE:(2) [802.3ae] WIS Test Pattern Error Counts


Just to be absolutely sure:

Does that mean that the sentence in 50.3.8 
(requiring a test pattern checker
to synchronize and report bit errors) 
will be removed from the spec?


> -----Original Message-----
> From: Tom Alexander [mailto:Tom_Alexander@xxxxxxxxxxxxxx]
> Sent: Monday, September 17, 2001 11:42 AM
> To: Nepple, Bruce; stds-802-3-hssg@xxxxxxxx
> Subject: RE: [802.3ae] WIS Test Pattern Error Counts
> Bruce,
> Your interpretation of D3.2 is correct. As per the resolution to
> Comment #53 against D3.1, the existing bit error mechanisms are to
> be used to detect and report pattern bit errors, as specifically
> stated in the comment resolution:
> 	"...The method of measuring bit errors shall be to use the
> 	current B1, B2 and B3 SONET parity checking mechanisms in
> 	the WIS Receive process. No additional logic shall be added
> 	to the error checker for counting errors."
> There is no Path Bit Error mechanism or counter in the normal WIS
> processing, and therefore there is no Path Bit Error counter for
> test pattern mode, either in Clause 50 or Clause 45.
> There was an extensive discussion on this subject during the
> comment resolution meeting. The general consensus was that the
> existing B1/B2/B3 parity checks provided sufficient capability
> for detecting test pattern bit errors, and also for providing
> a rough assessment of the bit error rate. The view was that there
> was no good reason to increase the WIS complexity by providing
> additional hardware to measure the bit error rate more precisely.
> I hope this answers your question.
> Best regards,
> - Tom Alexander
> WIS Scribe
> -----Original Message-----
> From: Nepple, Bruce [mailto:bnepple@xxxxxxxxxxxxxxxxxxx]
> Sent: Friday, September 14, 2001 7:26 PM
> To: stds-802-3-hssg@xxxxxxxx
> Subject: [802.3ae] WIS Test Pattern Error Counts
> In 50.3.8 of D3.2 it is indicated that the WIS test pattern checker 
> shall have the ability to synchronize to the mixed frequency 
> test pattern and report bit errors detected within the payload 
> to the Station Management entity.  It then goes on to describe 
> the Section BIP, Line BIP, and Path Block error counters, but 
> makes no mention of a Path Bit Error Counter.  Did I miss 
> something?  The three counters mentioned above will function 
> without a bit checker through the standard parity bytes.
> I didn't see such a counter in 45.2.2 either.
> Thanks
> Bruce