The Cisco TwinGig Converter Module (model CVR-X2-SFP), also known as a converter module, is a hot-swappable input/output (I/O) device that slides into a 10-Gigabit Ethernet X2 slot on a switch. It converts the 10-Gigabit X2 interface into a dual SFP interface. It was developed for the Catalyst 3560-E switch but is supported on other platforms.
Figure 1 Cisco TwinGig Converter Module
The converter module supports up to two small-form factor pluggable (SFP) modules. These modules plug into the converter module slots to establish fiber-optic and copper connections to network devices. Table 1 lists the SFP modules that the converter module supports.
Note Use only Cisco SFP modules in the converter module. Each Cisco module has an internal serial EEPROM that is encoded with security information. This encoding provides a way for Cisco to identify and validate that the module meets the requirements for the switch.
SFP Module Number
1000BASE-BX, 1490 nm1
1000BASE-BX, 1310 nm
CAB-SFP-50CM (3560-E only)
SFP module patch cable2
1 nm = nanometer
2 The Catalyst 3560-E switch supports the SFP module patch cable, a 0-5-meter, copper, passive cable with SFP module connectors at each end. The patch cable can connect two Catalyst 3560-E switches in a cascaded configuration.
Table 2 lists the fiber-optic cabling specifications for the SFP modules that you install in the converter module. Each port must match the wavelength specifications on the other end of the cable, and the cable must not exceed the stipulated cable length. The SFP modules using fiber-optic connections need fiber-optic cables with LC/PC or LC/UPC connectors. The SFP modules using copper connections need Category 5E cables with RJ-45 connectors. Copper 1000 BASE-T SFP modules use standard four twisted pair category 5E cable at lengths up to 328 feet (100 meters).
Core Size (micron)
Modal Bandwidth (MHz/km)
6562 feet (2 km)
722 feet (220 m)
1804 feet (550 m)
43.4 to 62 miles (70 to 100 km)3
32,810 feet (10 km)
Coarse Wave Division Multiplexing (CWDM)
1470, 1490, 1510, 1530, 1550, 1570, 1590, 1610
62 miles (100 km)
Dense Wave Division Multiplexing (DWDM)
100GHz ITU channels 20 to 59
62 miles (100 km)
1 A mode-conditioning patch cord is required.
2 ITU-T G.652 SMF as specified by the IEEE 802.3z standard.
3 1000BASE-ZX modules can send data up to 62 miles (100 km) by using dispersion-shifted SMF or low-attenuation SMF; the distance depends on the fiber quality, the number of splices, and the connectors.