The maximum speed of an SFP (Small Form-factor Pluggable) port depends on the specific type of SFP module being used. SFP modules support various data rates, and the most common ones include: 

1. 1 Gbps (Gigabit per second):

• This is the standard data rate for many SFP modules, and it's widely used for Fast Ethernet and Gigabit Ethernet applications. SFP modules that operate at 1 Gbps are often referred to as "1G SFP" or "1G SFP transceivers."

2. 10 Gbps (Gigabit per second):

• Some SFP+ (enhanced Small Form-factor Pluggable) modules support 10 Gbps, which is commonly used for 10 Gigabit Ethernet applications. These modules are often referred to as "10G SFP+" or "10G SFP+ transceivers."

3. 25 Gbps (Gigabit per second):

• SFP28 (Small Form-factor Pluggable 28) modules support 25 Gbps and are commonly used for 25 Gigabit Ethernet applications. These modules are often referred to as "25G SFP28" or "25G SFP28 transceivers."

4. 40 Gbps (Gigabit per second):

• Some QSFP (Quad Small Form-factor Pluggable) modules support 40 Gbps, typically in the form of 40 Gigabit Ethernet applications. These modules are often referred to as "40G QSFP" or "40G QSFP transceivers."

5. 100 Gbps (Gigabit per second):

• QSFP28 (Quad Small Form-factor Pluggable 28) modules support 100 Gbps and are commonly used for 100 Gigabit Ethernet applications. These modules are often referred to as "100G QSFP28" or "100G QSFP28 transceivers."

It's important to note that the maximum speed of an SFP port is determined by the type of SFP module installed in the port and the capabilities of the networking equipment. When selecting SFP modules and networking devices, ensure that the data rates are compatible to achieve optimal performance in your network.