Is it possible to interconnect Optical 10G SFP+, XFP, X2 and XENPAK Transceivers?

With the development of new network technologies, new transceivers emerged on the market. These transceivers brought more advanced features and stability options compared to previous models. Such is the case with the 10G Ethernet transceivers. The first and original 10G Ethernet transceiver is XENPAK. Even though these transceivers are very old, they are still widely popular in network infrastructures. As time passed by, the leading manufacturers were looking for a simpler and more compact solution for the 10G Ethernet and they developed the X2 transceiver. This transceiver is smaller than the XENPAK and provides a more advanced features. It is considered as the successor of XENPAK with SC connector. The first small form factor transceiver emerged with the development of the XFP. The XFP is at least a half smaller than the X2 and it presents the LC connector. XFP modules are hot-swappable and protocol-independent and they typically operate at near-infrared wavelengths of 850 nm, 1310 nm or 1550 nm. At last the SFP+ was introduced as the final (for now) solution for 10GB Ethernet. It is a Small Form-Factor Pluggable transceiver which uses the same physical form-factor as a gigabit SFP transceiver. Because of their similarity they offer flexibility and many switches provide both 1GB and 10GB ports. In comparison to earlier XENPAK or XFP modules, SFP+ modules leave more circuitry to be implemented on the host board instead of inside the module.

When it comes to interconnecting all of these transceivers the most important thing is that their optics must match. Because some of these offer a cost-effective solution it is perfectly acceptable to connect an X2 to an SFP, or a SFP+ to a XENPAK, or any other combination.

Here are few examples of mixing these transceivers with each other:

• Interconnecting SFP-10G-SR to XENPAK-10GB-SR or X2-10GB-SR is possible with a correct optics on each end. If for example the optics are single-mode you will need single-mode patch cords. If the optics are multi-mode then you will need multi-mode patch cords. Because both XENPAK-10GB-SR and X2-10GB-SR are multi-mode, multi-mode cables would be needed.
• Interconnecting LC-SC patch cords for X2-10GB-SR and SFP-10G-SR is possible even though the SFP-10G-SR requires LC connector and X2 requires SC connector. When connecting these two transceivers the use of a LC-SC patch cable is a must.
• Even though SFP+ transceivers are smaller than XFP transceivers, interconnecting them is possible because both of them are 10GB transceivers. However choosing SFP+ over XFP will bring some advantages to the table. For example the SFP+ transceivers are more compact in size, they can connect with the same type of XFP, X2 and XENPAK directly and they are cheaper to purchase.

The differences between these transceivers can be found below:

If you want to interconnect these transceivers the most important rule to follow is to ensure their optics match. Their detailed properties can be found in their datasheets. However, even though connecting these transceivers with each other is possible, it is highly advisable to use the same type of transceiver on both ends of the connection.