Datasheet

15-32
Cisco ONS 15454 SDH Reference Manual, R7.0
October 2008
Chapter 15 Performance Monitoring
15.7.1 STM-1 Card Performance Monitoring Parameters
100 GHz card, the OC192 SR/STM64 IO 1310 card, the OC192 IR/STM64 SH 1550 card, OC192
LR/STM 64 LH 1550 card, the OC192 LR/STM64 LH ITU 15xx.xx, OC192 SR1/STM64IO Short Reach
card, and the OC192/STM64 Any Reach card.
On all STM-N optical cards, errors are calculated in bits instead of blocks for B1 and B3. This means
there could possibly be a slight difference between what is inserted and what is reported on CTC. In
STM4, for example, there are approximately 15,000 to 30,000 bits per block (per ITU-T-G.826). If there
were two bit errors within that block, the standard would require reporting one block error whereas the
STM-N cards would have reported two bit errors.
When a tester inputs only single errors during testing, this issue would not appear because a tester is not
fast enough to induce two errors within a single block. However, if the test is performed with an error
rate, certain error rates could cause two or more errors in a block. For example, since the STM4 is
roughly 622 Mbps and the block in the STM4 has 15,000 bits, there would be about 41,467 blocks in a
second. If the tester inputs a 10e
–4
error rate, that would create 62,200 errors per second. If the errors are
distributed uniformly, then CTC could potentially report two bit errors within a single block. On the
other hand, if the error ratio is 10e
–5
, then there will be 6,220 errors per second. If the errors are not
distributed uniformly, then CTC might report one bit error within a single block. In summary, if the
errors are distributed equally, then a discrepancy with the standard might be seen when a tester inputs
10e
–4
or 10e
–3
error rates.
15.7.1 STM-1 Card Performance Monitoring Parameters
Figure 15-8 shows where overhead bytes detected on the ASICs produce performance monitoring
parameters for the OC3 IR 4/STM1 SH 1310 card and the OC3 IR/STM1 SH 1310-8 card.
Figure 15-8 PM Read Points on the STM-1 Cards
The PM parameters for the STM-1 and STM1 SH 1310-8 cards are listed in Table 15-16. The parameters
are defined in Table 15-3 on page 15-5.
71104
ONS 15454 SDH
STM-1 Card
Pointer Processors
BTC
ASIC
Cross-Connect
Card E1
RS-EB
RS-BBE
RS-ES
RS-SES
MS-EB
MS-BBE
MS-ES
MS-SES
MS-UAS
MS-PPJC-Pdet
MS-NPJC-Pdet
MS-PPJC-Pgen
MS-NPJC-Pgen
High-
Order
Path
Level
HP-EB
HP-BBE
HP-ES
HP-SES
HP-UAS
HP-ESR
HP-SESR
HP-BBER
PMs read on BTC ASIC
PMs read on PMC