Product overview<br><br>The Cisco® 25GBASE SFP28 (Small Form-Factor Pluggable) portfolio offers customers a wide variety of high-density and low-power 25 Gigabit Ethernet connectivity options for data center and high-performance computing networks applications. The 25G Modules are based on SFP28 form factor.<br><br>Cisco SFP-25G copper cables<br><br>Cisco SFP28 to SFP28 copper direct-attach 25GBASE-CR1 cables are suitable for very short links and offer a highly cost-effective way to establish a 25-Gigabit link between SFP28 ports of Cisco switches within racks and across adjacent racks. Cisco offers passive copper cables in lengths of x= 1, 1.5, 2, 2.5, 3, 4 and 5 meters.<br><br>1m, 1.5m, and 2m cables do not require FEC on the host ports; 2.5m and 3m cables require BASE-R FEC (also know as FC-FEC) on the host ports; 4m and 5m cables require RS-FEC on the host ports.<br><br>Cisco SFP-25G active optical cables<br><br>Cisco SFP28 to SFP28 Active Optical Cables are direct-attach fiber assemblies with SFP connectors. They are suitable for very short distances and offer a cost-effective way to connect within racks and across adjacent racks. Cisco offers Active Optical Cables in lengths of 1, 2, 3, 4, 5, 7, and 10 meters.<br><br>AOC cable require BASE-R FEC on the host ports.<br><br>Cisco SFP-25G-SR-S<br>The Cisco 25GBASE-SR Module supports a link length of 70/100m on OM3/4 MMF.<br>This module requires RS-FEC on the host ports.<br><br>Cisco SFP-10/25G-CSR-S<br><br>The Cisco 10/25GBASE-CSR Module supports a link length of up to 300/400m over OM3/4 at 10G, and up to 300/400m over OM3/4 at 25G*.<br><br>This module requires RS-FEC on the host port for full reach operation at 25G. Using BASE-R FEC the module can support 70/100m over OM3/4 and with-out FEC it can support 30/50m over OM3/4 at 25G*. For 10G operation FEC is not required.<br><br>Cisco SFP-10/25G-LR-S<br><br>The Cisco 10/25GBASE-LR Module supports a link length of 10 kilometers on standard Single-Mode Fiber (SMF) G.652 at both 10G and 25G.<br><br>This module requires RS-FEC on the host ports for operation at 25G.