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[EFM] Loop back and BERT test functionality for service providers




Matt,

The loop back BERT tests are very similar in function to the conformance 
tests that are done with Ethernet devices per the requirements of the 
standard.  The big difference is that they are done in the field, ad hoc by 
field test personnel and automated systems. I has occurred to me that the 
conformance test pattern for GbE could be used for this.

Coming out of the Raleigh meeting, there was supposed to be a group of 
people that were getting together at San Diego to discuss the functionality 
that was required by service providers for which they used a loop back 
test, and BERT testing.  That did not happen.  So that this discussion does 
not get bogged down again at the next meeting, here is the material that 
Bob Barrett and I put together on the topics.  I believe that I have 
already sent it to you once, but I could be mistaken.

Loop Back and BERT Test Functions

A Loop Back Test is a conformance test to verify the ability of a 
communications infrastructure and facility to meet certain performance and 
operational management capability requirements in order for a service 
provider to meet the contractual requirements of service level 
agreements.  During the loop back test, the customer revenue data stream is 
disabled and replaced with a loop back test pattern.  Often the default 
loop back test pattern is a worst case error free BERT pattern.  Loop back 
tests are run as part of a remote operations support function to prevent 
the need for sending people to perform the test and measurement functions 
at the customer site.  Minimal levels of loop back testing is also 
available to service provider customer to allow them to do their
own service conformance verification.

The loop back test performs the following functions:
1.      Verifies the full bandwidth capability of the service 
infrastructure and facility in both directions,
2.      Verifies that the operational management command and control 
functions operate properly under worst case load conditions of the revenue 
data stream in both directions,
3.      Verifies that the performance monitoring functions operate properly 
in both
directions,
4.      Verifies the data reliability performance of the infrastructure and 
service facility,
5.      Verifies that any fault reporting functions operate properly in 
both directions,
6.      Verifies that any other facility configuration and service 
management functions operate properly under worst case load conditions of 
the revenue data stream in both directions,
7.      Verifies that any service management and support functions operate 
properly in both directions regardless of revenue data stream load,
8.      Verifies the performance of the infrastructure and/or service 
facility as part of a customer problem resolution process,
9.      Verifies that an infrastructure and/or service facility are fully 
operational after having been properly repaired.

The Bit Error Rate Test (BERT) test, as used by service provider field 
operations, performs the following functions as part of a conformance loop 
back test:
1.      The data reliability performance measurements of the infrastructure 
and service facility under worst case revenue data stream load by measuring 
the bit error rate under worst case pattern and load conditions,
2.      Tests the performance monitoring capability of the infrastructure 
and service
facility by introducing errors into the revenue data stream using a test 
pattern with and without deliberate bit errors in the test pattern, without 
changing the error check function indicator,
3.      Verifies that some of the operational management command and 
control functions operate properly by forcing the near end and far end 
interfaces into and out of different BERT test functions while introducing 
errors into the revenue data stream test pattern.


Thank you,
Roy Bynum