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Cable Specifications for QSFP+ and QSFP28 Transceivers on QFX5120 Switches

 

The 40GbE QSFP+ and 100GbE QSFP28 transceivers used in QFX5120 switches use 12-ribbon multimode fiber crossover cables with MPO/UP, MPO/UPC, or MPO/APC socket connectors. The fiber can be either OM3 or OM4. We do not sell these cables.

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+ ports, ensure that the proper polarity is maintained through the cable plant.

Table 1 describes the signals on each fiber. Table 2 shows the pin-to-pin connections for proper polarity.

Table 1: QSFP+ and QSFP28 MPO Cable Signals

Fiber

Signal

1

Tx0 (Transmit)

2

Tx1 (Transmit)

3

Tx2 (Transmit)

4

Tx3 (Transmit)

5

Unused

6

Unused

7

Unused

8

Unused

9

Rx3 (Receive)

10

Rx2 (Receive)

11

Rx1 (Receive)

12

Rx0 (Receive)

Table 2: QSFP+ and QSFP28 MPO Fiber-Optic Crossover Cable Pinouts

Pin

Pin

1

12

2

11

3

10

4

9

5

8

6

7

7

6

8

5

9

4

10

3

11

2

12

1