The number of lanes in a QSFP (Quad Small Form-Factor Pluggable) transceiver depends on the specific variant of QSFP. QSFP modules come in various types, each supporting a different number of lanes. The two common types are QSFP28 and QSFP56-DD.

1. QSFP28 (Quad Small Form-Factor Pluggable 28):

• QSFP28 supports four lanes for data transmission, with each lane capable of carrying data at rates up to 25 gigabits per second (Gbps). The total aggregate data rate for a QSFP28 module is 100 Gbps (4 channels).

2. QSFP56-DD (Quad Small Form-Factor Pluggable Double Density):

• QSFP56-DD supports double the number of lanes compared to QSFP28. It has a total of 8 lanes for data transmission, with each lane operating at data rates of up to 50 Gbps. The total aggregate data rate for a QSFP56-DD module is 200 Gbps (8 channels).

In summary, QSFP28 has 4 lanes, and QSFP56-DD has 8 lanes. The number of lanes is a crucial factor in determining the overall data capacity and speed capabilities of the QSFP module. The higher the number of lanes, the greater the potential aggregate data rate that can be achieved by the transceiver.