0X9CT Dell 100GBE QSFP28 BIDI 850/900nm LC Duplex MMF Networking Transceiver

Electrical and Optical Interface

The module complies with the IEEE 802.3bm 100GBASE-SR10 and 100G以太网 Consortium's requirements for BIDI applications over multimode fiber. The achievable link distance is directly dependent on the grade of multimode fiber used. The 0X9CT is optimized for performance on modern OM3 and OM4 cabling. These distances are ideal for intra-data center applications such as connecting top-of-rack (ToR) switches to end-of-row (EoR) or spine switches, as well as interconnecting servers in high-performance computing (HPC) clusters.

Primary Applications and Use Cases

The Dell 0X9CT 100G BIDI transceiver is deployed in scenarios where high bandwidth, fiber efficiency, and cost management are paramount. Its design caters specifically to modern data center and enterprise network architectures. In two-tier spine-leaf architectures, the volume of east-west traffic is immense. The connections between leaf and spine switches require high-bandwidth, low-latency links. Using 0X9CT transceivers for these interconnects allows network operators to:

Migrating from 10G/40G to 100G Infrastructure

Many enterprises have existing MMF backbones installed for 10GBASE-SR or 40GBASE-SR4. The 0X9CT is a strategic tool for migrating to 100G. Because it uses the same duplex LC connector and OM3/OM4 fiber, the upgrade path is straightforward—often requiring only a swap of transceivers and switch line cards, without the need to re-pull fiber. This protects prior cabling investments and minimizes upgrade downtime and cost.

Mandatory Use of OM3 or OM4 Multimode Fiber

The 0X9CT is engineered for use with laser-optimized 50/125µm multimode fiber, specifically OM3 or OM4 grades. Older OM1 or OM2 fiber is not suitable for 100G applications at these distances due to higher modal dispersion. The link budget must account for connector and splice losses. It is recommended to keep end-face contamination to a minimum and ensure all patch cords and trunks are properly certified for the intended data rate.

Pairing and Polarity Management

BIDI links require specific attention to polarity to ensure the transmit wavelength on one end connects to the receive wavelength on the other. BIDI transceivers are typically deployed in matched pairs. For a link using the 0X9CT, one end must be configured for "Channel 0" (e.g., 850nm Tx / 900nm Rx) and the other for "Channel 1" (e.g., 900nm Tx / 850nm Rx). Duplex patch cables with a key-up to key-down flip (a crossed-over pair) are standard for establishing correct polarity in a BIDI link. Most modern duplex MMF patch cords are designed with this in mind.

Verifying Link Integrity with DDM

After installation, network engineers should immediately verify link performance using the DDM data available through the switch CLI or management software. Key parameters to check include received optical power (Rx Power), which should be within the transceiver's specified sensitivity and overload thresholds, and transmitter bias current. Monitoring these values provides early warning of potential fiber degradation or marginal connections.

Total Cost of Ownership (TCO) Advantage

The combined savings in fiber infrastructure, reduced conduit usage, simpler cable management, and lower per-module cost (compared to SMF solutions) contribute to a significantly lower TCO for deploying 100G links within the data center using the Dell 0X9CT BIDI transceiver. This makes it a financially and operationally superior choice for greenfield deployments within its distance range and for brownfield upgrades of existing MMF plants.

Compatibility

Ensuring proper compatibility and understanding deployment nuances is crucial for a successful implementation of the Dell 0X9CT transceiver. As a genuine Dell Networking transceiver, the 0X9CT is fully tested and supported on a wide range of Dell Power Switch (formerly Force10 and Power Connect) series, including but not limited to the S-series (e.g., S5248F-ON, S5296F-ON, S4148F-ON), Z-series, and C-series platforms. It is critical to verify the specific switch model and OS version compatibility via the official Dell Qualified Transceiver List to ensure full functionality and support entitlement. Using genuine Dell optics guarantees that Digital Diagnostics Monitoring (DDM) features for real-time temperature, voltage, TX bias current, and optical power will be accessible and accurate within the switch's operating system.