The Cisco 10GBASE-LW Module supports a link length of 10 kilometers on standard single-mode fiber (SMF) (G.652). WAN-PHY is intended to allow the transport of 10 Gigabit Ethernet over a traditional SONET/SDH infrastructure. The purpose of WAN-PHY is to render 10 Gigabit Ethernet compatible with SONET STS-192c format and data rate, as defined by ANSI, as well as the SDH VC-4-64c container specified by ITU.