| > a status attribute in the FDDI station phy port,
> estimated link error rate. Where is it documented ?
> what does it indicate, measure, etc.
The estimated link error rate is documented on page 109, section 5.8.4 of the
FDDI Data Link Functional Specification. It is described as:
Keyword Code Syntax Description
----------------------------------------------------------------------------------
Estimated Link Error | 6 | Integer | The Link Error Monitor current estimate
Rate | | | of the link error rate. For an attribute
| | | value of N, the actual rate is (on the order
| | | of) 10superscript(-N).
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The Link Error Monitor is a facility of SMT (Station Management) and is described
on page 20, section 2.4.4 of the FDDI Data Link Functional Specification.
The LEM is also discussed in Raj Jain's FDDI Handbook, ISBN 0-201-56376-2
published by Addison-Wesley Publishing Company on page 203, section 11.4.
The LEM is also discussed in Amit Shah's FDDI A High Speed Network, ISBN
0-13-308388-8, published by PTR Prentice-Hall, Inc. on page 127, section
7.4.2.4.
In summary, the LEM continously monitors the FDDI Ring for errors. If the
link error rate exceeds 10minus8, an alarm is signaled to SMT. If the link
further deterioates and exceeds 10minus7, the connection is flagged as
faulty, and taken off the ring. Since typical FDDI link error rates
are very low, the link error rate is only an estimate.
Mike Sheldon
|
| Hello Mike,
Thanks for your references and explanation of LEM. However, the
description does not explain how a real number (10minus7) translates
to, for example, a 15 in NCL? What does 15 represent and why does it
decrease or increase?
The customer is seeing the value decrease to 9 when there are problems
on the FDDI ring. At times when things are really bad, the value is
down to 4.
Thanks, Maria
|