glc-sx-mmd VS glc-lh-smd
What are the difference of cisco glc-sx-mmd and glc-lh-smd?
GLC-SX-MMD 1000BASE-SX SFP is made for Multi-mode Fiber only.
GLC-LH-SMD 1000BASE-LX/LH SFP is made for Both Multi-mode and Single-Mode Fibers.
GLC-SX-MMD, compatible with the IEEE 802.3z 1000BASE-SX standard,operates on legacy 50 μm multimode fiber links up to 550 m and on 62.5 μm Fiber Distributed Data Interface (FDDI)-grade multimode fibers up to 220 m.
GLC-LH-SMD, compatible with the IEEE 802.3z 1000BASE-LX standard, operates on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers.
GLC-SX-MMD, 850-nm wavelength, extended operating temperature range and DOM support, dual LC/PC connector.
GLC-LH-SMD, 1300-nm wavelength, extended operating temperature range and DOM support, dual LC/PC connector.
The follow screenshot shows the technical specification comparison.
image source: http://www.router-switch.com/glc-sx-mmd-p-4958.html