The MikroTik CRS328-4C-20S-4S+RM is a standalone high-density optical switch designed to act as a centralized distribution hub for fiber-to-the-home (FTTH) networks, campus backbones, and enterprise server infrastructures. Providing high port density and media flexibility, it enables network operators to manage complex optical fiber layouts without external media converters.
At its core, the switch is powered by a Marvell 98DX3236 single-core processor running at 800 MHz, backed by 512 MB RAM and 16 MB flash storage. The device provides non-blocking switching throughput across a total of 28 independent ports: 20x 1.25 Gbps SFP cages, 4x 10 Gbps SFP+ cages for multi-gigabit core trunks, and 4x Combo ports that allow administrators to select between Gigabit RJ45 copper or 1G SFP fiber interfaces based on physical deployment needs.
Built for mission-critical reliability, the CRS328-4C-20S-4S+RM features dual redundant internal AC power supplies (100–240 V AC) to ensure zero downtime during power supply failure or AC feed maintenance. Housed in a heavy-duty 1U steel rackmount chassis with included rack ears, it incorporates MikroTik's Dual Boot operating system selector, allowing users to boot into lightweight SwOS for fast Layer 2 wire-speed switching or full RouterOS Level 5 for enterprise VLAN routing, firewall policies, queues, and IPsec VPN capabilities.
Comprehensive Key Features
High-Density Optical Interface Array: Features 20x 1G SFP cages alongside 4x 10G SFP+ cages for high-capacity optical backhaul links.
4x Combo Gigabit Ports: Flexible combo interface blocks supporting software selection between 10/100/1000 Mbps RJ45 copper or 1G SFP optical connections.
Dual Redundant AC Power Supplies: Built-in dual hot-swappable internal power supplies ensure uninterrupted network uptime during power rail failovers.
Dual Boot Operating System Selector: Boot into Web-configurable SwOS for fast Layer 2 switching or complete RouterOS Level 5 for Layer 3 enterprise routing.
Wire-Speed Switching Capacity: Delivering 64 Gbps non-blocking throughput, 128 Gbps switching capacity, and 95.2 Mpps forwarding rate.
1U Rackmount Steel Chassis: Durable metal housing with included rack ears and active temperature-regulated cooling fans for continuous 24/7 server closet operation.
Extended Technical Specifications
1. Hardware & Physical Parameters
Model / SKU: CRS328-4C-20S-4S+RM
Dimensions: 0.443 m × 0.200 m × 0.044 m (443 × 200 × 44 mm)
Weight: 2.500 kg
CPU: Marvell 98DX3236 Single-Core @ 800 MHz
RAM: 512 MB
Storage: 16 MB Flash
1G SFP Cages: 20× 1.25 Gbps SFP Ports
10G SFP+ Cages: 4× 10 Gbps SFP+ Ports (supports 1.25G SFP and 10G SFP+ modules)
Combo Ports: 4× Combo Ports (10/100/1000 Mbps RJ45 or 1.25 Gbps SFP)
Console Port: 1× RJ45 Serial Console Port
Enclosure Material: 1U Heavy-Duty Steel Rackmount Chassis
Status LEDs: Power (1 & 2), User LED, Port Link/Activity Indicators
2. Wireless, Networking & Performance Parameters
Switching Capacity: 128 Gbps
Non-Blocking Throughput: 64 Gbps
Forwarding Rate: 95.2 Mpps
Operating System: Dual Boot (MikroTik SwOS / RouterOS License Level 5)
Architecture: ARM 32-bit
3. Electrical & Environmental Parameters
Power Supply Type: Dual Redundant Internal AC Power Supplies (100 – 240 V AC)
Max Power Consumption: 43 W
Cooling Type: Active Cooling (2x internal temperature-controlled fans)
Operating Temperature: -20°C to 60°C (-4°F to 140°F)