SFP MSA Compliance
The SFP Multi-Source Agreement (MSA) is an agreement that was drafted among competing manufacturers of
SFP optical modules. The SFF Committee was formed to oversee the creation and maintenance of these
agreements including the SFP MSA designated as INF-8074i. This agreement describes a mutually agreed upon
standard for the form and function of SFP modules. However, not all SFPs produced are MSA compliant. The
MSA provides for a transceiver (TX/RX) pinout. Other industries such as broadcast had the need for dual TX
and dual RX SFP for unidirectional applications such as video. Naturally, a non-MSA standard was introduced
allocating pinout assignments for dual output and dual input I/O configurations. In addition, the some of the
internal serial communication pins were reassigned.
The FOI/TD-6010 will accept any of these pinout schemes in any combination. For example, you can have an
MSA compliant SFP in the A position and a non-MSA SFP in the B position. Of course, functionality will be
dependent on using functionally compatible modules. Either of the
transceiver
pinout schemes in the
following table are acceptable in either SFP slot.
Pinout Comparison Chart
PIN
Transceiver (MSA)
Transceiver (Non-MSA)
Dual TX (Non-MSA)
Dual RX (Non-MSA)
1
VEE
VEE
VEE
VEE
2
TX_FAULT [VEE]
VEE
NC
Rx2-
3
TX_DIS
NC
NC
Rx2+
4
MOD_DEF(2) - SDA
VEE
VEE
VEE
5
MOD_DEF(1) - SCL
SCL
SCL
SCL
6
MOD_DEF(0) – PRESENCE [VEE]
SDA
SDA
SDA
7
Rate [NC]
VEE
VEE
VEE
8
LOS
RX1_LOS
Tx2+
NC
9
VEE
NC
Tx2-
NC
10
VEE
NC
Tx2_DIS
NC
11
VEE
VEE
VEE
VEE
12
RD-
Rx1-
NC
Rx1-
13
RD+
Rx1+
NC
Rx1+
14
VEE
VEE
VEE
VEE
15
VCC
VCC
VCC
VCC
16
VCC
VCC
VCC
VCC
17
VEE
VEE
VEE
VEE
18
TD+
Tx1+
Tx1+
NC
19
TD-
Tx1-
Tx1-
NC
20
VEE
Tx1_DIS
Tx1_DIS
NC