Juniper QFX3500 - Table 26: QSFP+ and QSFP28 Optical Module Receptacle Pinouts; Table 27: QSFP+ MPO Fiber-Optic Crossover Cable Pinouts

CAUTION: To maintain agency approvals, use only a properly constructed,
shielded cable.
TIP: Ensure that you order cables with the correct polarity. Vendors refer to
these crossover cables as key up to key up, latch up to latch up, Type B, or
Method B. If you are using patch panels between two QSFP+ or QSFP28
transceivers, ensure that the proper polarity is maintained through the cable
plant.
Table 26 on page 61 describes the signals on each fiber. Table 27 on page 61 shows the
pin-to-pin connections for proper polarity.
Table 26: QSFP+ and QSFP28 Optical Module Receptacle Pinouts
SignalFiber
Tx0 (Transmit)1
Tx1 (Transmit)2
Tx2 (Transmit)3
Tx3 (Transmit)4
Unused5
Unused6
Unused7
Unused8
Rx3 (Receive)9
Rx2 (Receive)10
Rx1 (Receive)11
Rx0 (Receive)12
Table 27: QSFP+ MPO Fiber-Optic Crossover Cable Pinouts
PinPin
121
112
61Copyright © 2017, Juniper Networks, Inc.
Chapter 7: Transceiver and Cable Specifications