Finisar AN-2030 - Manual (Page 8)

AN-2030: Digital Diagnostic Monitoring Interface for Optical Transceivers
F i n i s a r
9/26/02 Revision D Page 8
The SONET compliance code bits allow the host to determine with which specifications
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a SONET transceiver complies. For each bit rate defined in Table 3.5 (OC-3, OC-12, 2
OC-48), SONET specifies short reach (SR), intermediate reach (IR), and long reach 3
(LR) requirements. For each of the three bit rates, a single short reach (SR) 4
specification is defined. Two variations of intermediate reach (IR-1, IR-2) and three 5
variations of long reach (LR-1, LR-2, and LR-3) are also defined for each bit rate. Byte 6
4, bits 0-2, and byte 5, bits 0-7 allow the user to determine which of the three reaches 7
has been implemented – short, intermediate, or long. Two additional bits (byte 4, bits 3- 8
4) are necessary to discriminate between different intermediate or long reach variations. 9
These codes are defined in Table 3.4a. 10
Table 3.4a: SONET Reach Specifiers 11
Speed Reach Specifier bit 1 Specifier bit 2 Description
OC-3/OC-12/OC-48 Short 0 0 SONET SR compliant
OC-3/OC-12/OC-48 Intermediate 1 0 SONET IR-1 compliant
OC-3/OC-12/OC-48 Intermediate 0 1 SONET IR-2 compliant
OC-3/OC-12/OC-48 Long 1 0 SONET LR-1 compliant
OC-3/OC-12/OC-48 Long 0 1 SONET LR-2 compliant
OC-3/OC-12/OC-48 Long 1 1 SONET LR-3 compliant
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Encoding 13
The encoding value indicates the serial encoding mechanism that is the nominal design 14
target of the particular SFP. The value shall be contained in the serial data. The defined
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encoding values are shown in table 3.5. Finisar Gigabit Ethernet/Fibre Channel 16
transceivers have this byte set to 01h (8B/10B encoding), and SONET transceivers 17
(including all SONET multi-rate transceivers) are set to 05h (SONET Scrambled). 18
Table 3.5: Encoding codes 19
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Code Description of encoding mechanism
00h Unspecified
01h 8B10B
02h 4B5B
03h NRZ
04h Manchester
05h SONET Scrambled
06h -FFh Reserved
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