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Cisco ONS 15600 SDH Reference Manual, Release 9.0
78-18400-01
Chapter 12 Performance Monitoring
12.4 Performance-Monitoring Parameter Definitions
Slips cause different effects in service. Voice service has intermittent audible clicks. Compressed voice
technology has short transmission errors or dropped calls. Fax machines lose scanned lines or experience
dropped calls. Digital video transmission has distorted pictures or frozen frames. Encryption service
loses the encryption key, which causes data to be transmitted again.
Pointers align the phase variations in VC4 and TU payloads. The VC4 payload pointer is located in the H1
and H2 bytes of the line overhead. Clocking differences are measured by the offset in bytes from the
pointer to the first byte of the VC4 virtual container (VC) called the J1 byte. A small number of pointer
justification counts per day is not cause for concern. If the pointer justification count continues to rise
or becomes large, action must be taken to correct the problem.
You can enable positive pointer justification count (PPJC) and negative pointer justification count
(NPJC) performance monitoring parameters for LTE cards.
PPJC is a count of path-detected (PPJC-Pdet) or path-generated (PPJC-Pgen) positive pointer
justifications depending on the specific PM name. NPJC is a count of path-detected (NPJC-Pdet) or
path-generated (NPJC-Pgen) negative pointer justifications depending on the specific PM name.
A consistent pointer justification count indicates clock synchronization problems between nodes. A
difference between the counts means the node transmitting the original pointer justification has timing
variations with the node detecting and transmitting this count. Positive pointer adjustments occur when
the frame rate of the VC is too slow in relation to the rate of the VC4.
For pointer justification count definitions, see the
“12.4 Performance-Monitoring Parameter
Definitions” section on page 12-3
. In CTC, the PM count fields for PPJC and NPJC appear white and
blank unless IPPM is enabled.
12.4 Performance-Monitoring Parameter Definitions
gives definitions for each type of performance-monitoring parameter found in this chapter.
Table 12-1
Performance Monitoring Parameters
Parameter
Definition
MS-EB
Multiplex Section Errored Block (MS-EB) indicates that one or more bits are in error
within a block.
MS-ES
Multiplex Section Errored Second (MS-ES) is a one-second period with one or more
errored blocks or at least one defect.
MS-SES
Multiplex Section Severely Errored Second (MS-SES) is a one-second period which
contains 30 percent or more errored blocks or at least one defect. SES is a subset of
ES. For more information, see ITU-T G.829 Section 5.1.3.
MS-BBE
Multiplex Section Background Block Error (MS-BBE) is an errored block not
occurring as part of an SES.
MS-UAS
Multiplex Section Unavailable Seconds (MS-UAS) is a count of the seconds when the
section was unavailable. A section becomes unavailable when ten consecutive
seconds occur that qualify as MS-SESs, and it continues to be unavailable until ten
consecutive seconds occur that do not qualify as MS-SESs. When the condition is
entered, MS-SESs decrement and then count toward MS-UAS.
MS-FC
Count of the number of occurrences of near-end failure events, and is incremented by
one each time a near-end failure event begins. Failure counts are incremented during
unavailable time.
