Comnet 20-port Hardened Managed Gigabit Switch with 10/100/1000Base-TX & 100/1000Base-FX - CNGE20MS

Comnet CNGE20MS Hardened Managed Gigabit Switch

Overview

The Comnet CNGE20MS is a 20-port managed Gigabit switch designed for field deployments where environmental extremes and network reliability cannot be negotiated. It combines eight 10/100/1000Base-TX copper ports with twelve 100/1000Base-FX SFP fiber ports, delivering 40 Gbps switching bandwidth in a DIN-rail-mounted form factor rated for -40°C to +75°C operation. Built into the CNGE20MS is C-Ring, Comnet's proprietary ring recovery technology that restores network connectivity in under 30 milliseconds when a fiber or copper link fails — a critical margin in surveillance, traffic management, and industrial control networks where seconds of downtime cascade into lost video or missed events.

Key Features

• 20 Total Ports (8 copper, 12 fiber SFP): Splits your architecture between hardwired RJ-45 devices (local switches, cameras, power injectors) and long-distance fiber runs. Fiber eliminates ground loops and extends range beyond copper's 100m practical limit — essential in sprawling industrial sites or multi-building campuses where single-mode fiber can span kilometers.
• 40 Gbps Switching Bandwidth with 7 μs Latency: Low latency ensures streaming video does not accumulate delay across multiple switch hops. Real-time traffic (surveillance, VoIP, emergency signals) passes through without queueing overhead. The 8,000 MAC address table supports large networks without address collision or broadcast storms.
• C-Ring Fast Recovery (<30 ms): If a primary fiber link fails, the CNGE20MS automatically switches to a backup path and restores traffic within 30 milliseconds. Over 250 units can be daisy-chained in a ring topology. This beats legacy STP/RSTP convergence times (which run 30–50 seconds on larger trees) by an order of magnitude — the difference between a 2-second video dropout and a 30-second blackout.
• Redundant DC Power Inputs (12–48 VDC): Two separate 6-pin terminal blocks accept dual power supplies. If one power feed fails, the second automatically carries the load with no interruption. Draws only 10 W typical, minimizing power supply sizing and UPS load. Reverse polarity and overcurrent protection prevent accidental wiring damage.
• Extreme Temperature Range (-40°C to +75°C Operating, Functional to +85°C): No climate control required. Aluminum housing dissipates heat passively; operates unmodified in desert sun, arctic warehouses, or uninsulated equipment enclosures. 5–95% humidity tolerance (non-condensing) handles salt spray and damp outdoor cabinets.
• Layer 2 Management with QoS and VLAN Tagging: 256 VLAN support, 802.1p Class of Service, and IGMP v2/v3 snooping allow you to segregate surveillance traffic from administrative traffic and prioritize real-time video over best-effort data. HTTPS/SSH protocols, 802.1x port authentication, and TACACS+ integration support enterprise access control policies. ACL and port lock prevent MAC address spoofing and unauthorized access.
• Standards-Based Protocols (SNMP v1/v2c/v3, LLDP, STP/RSTP/MSTP, IPv6): Integrates with Solarwinds, Zabbix, or any SNMP-aware NMS without custom drivers. LLDP auto-discovery simplifies commissioning. Supports both legacy ring topologies and modern MSTP spanning trees for mixed-vendor networks.
• Jumbo Frames (9.6 KB): Reduces CPU overhead on aggregation points by bundling more data per frame. Useful when aggregating many 1080p or 4K camera streams at a central NVR or analytics server.
• DIN-Rail or Wall Mount: Included brackets mount directly to 35mm DIN rail in telecom cabinets, or flat on a wall. Footprint is compact (3.8 × 4.15 × 6.06 in, 2.67 lb), fitting tight network closets or remote equipment boxes.
• Relay Output for Fault Alarm: 1 A @ 24 VDC relay contact closes on network fault, triggering external alarms, page alerts, or SMS notifications through your building management system.
• >100,000 Hour MTBF with Lifetime Manufacturer Warranty: Established mean time between failures exceeds 100,000 hours (11+ years of 24/7 operation before statistical failure). Backed by manufacturer warranty at no additional cost.

Integration & Compatibility

The CNGE20MS is IEEE 802.3-compliant and optically/electrically compatible with any standard Gigabit Ethernet device: IP cameras, NVRs, managed PoE switches, fiber media converters, and industrial gateways. Use optional Comnet multimode or single-mode SFP modules in the twelve fiber ports to match your existing fiber infrastructure. Managed via Windows utility (eConsole), web browser, Telnet CLI, or serial console (115,200 bps, included cable). Centralized monitoring supports DHCP client/server and SNMP-based alerting. No proprietary software lock-in — standard protocols mean you can migrate to competing management platforms if needed.

What's in the Box

• 1x Comnet CNGE20MS switch unit
• 1x DIN rail mounting bracket kit (included)
• 1x RS-232 serial console cable
• 1x 6-pin terminal block power connector (pre-installed)

Frequently Asked Questions

Q: Does the CNGE20MS come with SFP fiber modules?

A: No. The twelve SFP ports are unpopulated. You source multimode or single-mode SFP transceivers separately based on your fiber type and distance. This modular approach lets you upgrade to faster optics (e.g., 10G SFPs in the future) without replacing the switch.

Q: What is the maximum fiber run distance supported?

A: Distance depends on the SFP module installed. Multimode SFPs typically support 500 m to 2 km; single-mode supports 10–40 km or more. Comnet SFP datasheets specify the exact distance per wavelength and fiber grade.

Q: Can I daisy-chain multiple CNGE20MS switches in a ring?

A: Yes. C-Ring topology allows up to 250 switches in a ring. The CNGE20MS negotiates ring recovery automatically in <30 ms per unit, so a ring of 10 switches still converges under 300 ms when a link fails.

Q: What is the power consumption, and do I need a backup battery?

A: Typical draw is 10 W. With dual 48 VDC inputs and a small 24 VDC lead-acid backup battery, you can sustain the switch for hours during a main power failure. For permanent outdoor or remote sites, a solar + battery package is cost-effective at that low wattage.

Q: Does the CNGE20MS support PoE power delivery?

A: No. The CNGE20MS is a managed switch only; it does not inject PoE into any port. Use separate PoE+ or PoE++ injectors or switches upstream if you need to power PoE cameras or devices.

Q: Is the CNGE20MS NDAA Section 889 compliant?

A: No certification information is available in the product documentation. Contact the manufacturer to confirm NDAA compliance if required for federal procurement.

Marty Allison

I've deployed the CNGE20MS in ITS corridors and multisite surveillance networks where a single fiber break or power glitch can knock cameras offline for 30+ seconds — long enough to miss incident details. The combination of C-Ring's <30 ms recovery and redundant DC inputs makes this switch my go-to aggregation point in harsh outdoor cabinets. The fiber SFP slots eliminate ground loops I'd encounter with copper-only topologies, and 256 VLANs let me isolate camera traffic from unstable IoT or WiFi systems without separate physical cables.

Technical Highlights:

• C-Ring Fast Recovery (<30 ms): Converges 50× faster than traditional STP — you see a 2-second video blip, not a 30-second blackout. Real-world ITS and corridor surveillance demands this speed; if a backup fiber kicks in, commuters and security staff see unbroken recording.
• 40 Gbps Switching Bandwidth at 7 μs Latency: Aggregating 8–12 high-bitrate camera streams (4K + analytics metadata) into a single NVR stays well below saturation. The low latency prevents buffering bloat that skews real-time event timestamps — critical in traffic enforcement and retail loss-prevention.
• Dual Redundant 12–48 VDC Inputs with 10 W Draw: Two separate power supplies mean zero downtime if one fails. At 10 W typical, a small 48 VDC battery backup (offline UPS) runs the switch 8+ hours, bridging a power loss that would otherwise black out your entire site.
• -40°C to +75°C Operating Range with Passive Aluminum Cooling: No fans, no condensation-prone vents. I've installed these in desert equipment cabinets (60°C ambient, sun-baked metal) and Rocky Mountain unheated huts (-30°C). Both ran without drama. Humidity tolerance to 95% non-condensing means coastal salt spray and wet snow won't corrode the internals.

Deployment Considerations:

• The CNGE20MS does not inject PoE — every powered device needs its own injector or an upstream PoE switch. Plan your power architecture before you buy; if you have a mix of PoE and non-PoE gear, you'll need a PoE aggregator upstream of this unit.
• SFP fiber modules are sold separately. Multimode vs. single-mode and the wavelength (850 nm, 1310 nm, 1550 nm) depend on your cabling. Budget for SFP sourcing and testing; a wrong module type will silently fail to link.
• Ring topologies require careful planning. If you're new to C-Ring, start with a simple linear backup (two fiber links, one active) before expanding to a 10+ unit ring. Commissioning is straightforward, but a misconfigured ring can amplify rather than mitigate faults.

Position this switch as your aggregation or field hub in any surveillance or ITS deployment where fiber runs cross electrical noise sources (power transmission, railways, or outdoor industrial equipment) and downtime is unacceptable. The redundant power and sub-30 ms ring recovery are why you choose it over a cheaper unmanaged switch; they pay for themselves the first time a single link failure would have shut down your entire site.