M2100, M2110, M2120 Analysis - HP 37717C Operating Manual

Communications performance analyzer, pdh / dsn

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PDH / DSn Testing With The HP 37717C

M2100, M2110, M2120 Analysis

Application

Previously ITU-T G.821 was the only international recommendation available to

measure the quality of a communications link. ITU-T G.821 was originally an "Out

of Service" measurement and analysis for commissioning a link and troubleshooting

during severe disruption. The commissioning test was a one month "Out of Service"

test based on errored and severely errored seconds. A one month test with the

subsequent loss of revenue is clearly unacceptable.

Due to demand ITU-T G.821 also evolved into proprietary methods for "In Service"

testing based on FAS and code errors. Demand for high quality leased lines meant

an "In Service" performance standard, closer to real conditions and allowing

comparisons between providers, was required.

The ITU-T M.2100 series was speciﬁcally deﬁned to provide a clear indication of

link quality, for service providers using long term performance analysis. "Bringing

into Service" and "repair criteria" analysis were also included.

M.2100 analysis is based on frame errors and provides Error Seconds (anomaly),

Severely Errored Seconds (defect) and Unavailability results for receive and

transmit directions. Transmit results are only available for 2 Mb/s signals with CRC

framing. "Out of Service" testing is only available for the receive direction. M.2110

is an "Out of Service" measurement for "bringing into service" testing of paths. A

15 minute BER test (G.821) is performed and if this is error free a 24 hour M.2110

test is performed. If the 24 hour M.2110 test displays PASS (S1 limit not reached)

the path can be returned to service. If FAIL is displayed (S2 limit reached or

exceeded) the 15 minute BER test should be repeated, If m-d-;- (UNCERTAIN)is

displayed (result between the S1 and S2 limits) run the 7 day BIS test.

The PASS FAIL and UNCERTAIN parameters are determined by the S1 and S2

limits which are user selectable.

UNACCEPTABLE

REGION OF UNCERTAINTY

BIS Objective (BISO)

BRING INTO SERVICE

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