MikroTik CRS310-1G-5S-4S+IN Switch – SMB Network Switch with SFP and SFP+ Ports

The MikroTik CRS310-1G-5S-4S+IN is an indoor fiber switch with 5 x 1G SFP ports, 4 x 10G SFP+ ports, and one Gigabit Ethernet port, designed for small ISPs, offices, and infrastructures where fiber optic connections over distances exceeding 100 meters are the primary requirement. It is widely used as a direct upgrade for existing CRS212 installations, as a fiber distribution switch in office buildings, and as an aggregation node in ISP networks where optical fiber eliminates the electromagnetic interference, tampering, and attenuation issues associated with copper cabling. Hardware offloaded VLAN filtering and Layer-3 routing support make it suitable for both simple switching scenarios and more complex network topologies.

The switch is built on the Marvell 98DX226S chip with a dual-core ARM processor at 800 MHz and 256 MB RAM, managed via RouterOS v7 or SwitchOS (License Level 5). The Gigabit Ethernet port has a direct connection to the switch chip for full Gigabit speed without bandwidth sharing, and supports 802.3af/at PoE-in as an additional powering option. The five SFP ports cover 1G connections over single-mode or multimode fiber, while the four SFP+ ports provide 10G uplinks or direct connections to servers and NAS devices with 10G interfaces. Dual boot between RouterOS v7 and SwitchOS provides management flexibility depending on deployment complexity.

The CRS310-1G-5S-4S+IN mounts in a standard 1U rack and integrates into existing fiber infrastructures as an access or distribution switch, with hardware offloading for 802.1Q VLAN filtering and Layer-3 routing that relieves the CPU from packet processing tasks at scale. Dual powering via DC jack at 18-57V and PoE-in provides flexibility in installations where power source access is limited. The RJ45 console and CPU and PCB temperature monitoring ensure operational visibility and direct access for configuration and troubleshooting.

It is recommended for small ISPs building 10G fiber distribution in buildings or over distances exceeding 100 meters, offices upgrading from copper switches to fiber to eliminate electromagnetic interference and improve physical link security, installations where CRS212 has reached its performance limits and a more capable platform with hardware offloading is required, and any environment where optical fiber is the preferred alternative to UTP for backbone connections. An operating temperature range of -40°C to +70°C and CE certifications confirm suitability for indoor technical environments.