Cisco 10-3105-02 10gbase-sr Lc/pc Multi-mode - Up To 1310 Ft - 850 Nm Transceiver Module

Cisco 10-3105-02 10GBASE Short-Range Fiber Built for High-Density 10 Gigabit Networks

The Cisco 10-3105-02 10GBASE-SR LC/PC multimode transceiver module addresses one of the most common needs in modern enterprise, campus, and data center networks: efficient, cost-effective 10 Gigabit connectivity over short distances. Operating at a nominal wavelength of 850 nm and optimized for duplex multimode fiber (MMF) with LC/PC connectors, this optics form factor enables wire-speed 10 GbE links with low power draw and simple, hot-swappable installation. Typical reach profiles span fiber types from legacy OM2 to high-performance OM4/OM5, allowing well-planned cabling plants to achieve distances of up to approximately 1310 ft (≈ 400 m) under ideal conditions. Whether you are equipping top-of-rack (ToR) switches, building aggregation layers, or upgrading server uplinks, a short-range 10 GbE optic like the Cisco 10-3105-02 streamlines deployment and standardizes spares across teams.

Short-Range 10 GbE Optics Fit in the Broader Optical Landscape

Not every 10 Gigabit application requires the long-haul reach of single-mode solutions. Inside buildings, between rows in a data hall, or across a floor in an office tower, most fiber runs are well under half a kilometer. 10GBASE-SR is purpose-built for these scenarios, leveraging 850 nm vertical-cavity surface-emitting lasers (VCSELs) to drive cost-effective multimode links. The Cisco 10-3105-02 belongs to this short-reach category, pairing compact optics and LC/PC connectors to minimize capex, simplify cable management, and keep thermals in check. Compared with twinax DACs, SR optics provide greater flexibility and extended distance; compared with LR single-mode modules, they reduce fiber costs and loosen tolerances for tight-radius, high-density cable routing.

Typical Roles and Use Cases

• Top-of-Rack to End-of-Row: Uplinks from servers or TOR switches to aggregation/leaf switches within the same row, often in the 10–100 m range.
• Campus Fiber Runs: Closet-to-closet or MDF-to-IDF connections within a building, taking advantage of existing OM3/OM4 cabling to keep upgrade costs down.
• Storage Fabrics: Low-latency links for iSCSI, NFS, and SMB3 (RDMA-capable infrastructures included) where consistent 10 GbE throughput is required.
• Virtualization Hosts: High-bandwidth uplinks from hypervisor nodes to spine/leaf fabrics, enabling vMotion/live migration, storage over Ethernet, and east-west traffic.
• High-Density Aggregation: Environments that demand many 10 GbE ports per rack with clean cable dressing and reduced airflow obstruction.

Key Characteristics of the Cisco 10-3105-02 10GBASE-SR Module

The Cisco 10-3105-02 embodies the expected characteristics of an SR-class 10 GbE optic while aligning with the physical and electrical behaviors required for seamless integration in Cisco switching and routing platforms. The following attributes summarize what to expect during planning and deployment.

Optical Wavelength and Fiber Type

Operating at 850 nm, the module targets duplex multimode fiber with LC/PC connectors. The “PC” denotes physical contact end-face geometry—standard in enterprise LC connectors—designed to reduce back reflection compared with older flat-polish styles. The module uses two fibers (transmit and receive) and relies on the modal bandwidth characteristics of OM-class MMF to achieve its maximum distances.

Reach Expectations by Cable Grade

Real-world reach depends on fiber core size, modal bandwidth, connector quality, and installation practices. A common planning baseline for 10GBASE-SR links is:

• OM2 (50/125 µm, legacy installations): tens of meters up to ≈ 82 m in optimal conditions.
• OM3 (laser-optimized 50/125 µm): up to ≈ 300 m in favorable scenarios.
• OM4 (enhanced laser-optimized 50/125 µm): up to ≈ 400 m (≈ 1310 ft), the most common target for new campus/data-center MMF plants.
• OM5 (wideband MMF): reach similar to OM4 for 10GBASE-SR; OM5 adds value primarily for SWDM applications rather than SR itself.

Hot-Swappable Simplicity and Operational Efficiency

Hot-swap behavior is essential in environments where downtime must be minimized. The Cisco 10-3105-02 supports tool-less insertion/removal from compatible cages, allowing maintenance teams to replace optics without shutting down chassis or line cards. This property also facilitates rapid troubleshooting: swap a suspected optic with a known good spare, re-test, and restore service in minutes.

Digital Diagnostics (DDM/DOM) for Proactive Monitoring

Digital optical monitoring—frequently referred to as DDM or DOM—exposes telemetry such as transmit optical power, receive optical power, module temperature, and supply voltage. Surfacing these values through the network OS (for example, via CLI or streaming telemetry) allows operations teams to:

• Trend link health: Catch gradual insertion-loss increases caused by contamination or fiber micro-bends.
• Correlate alarms: Distinguish between low RX power due to a damaged patch cord versus a marginal remote transmitter.
• Verify installations: Confirm power levels and temperature immediately after commissioning to establish a baseline.

Low Power Profile and Thermal Considerations

SR optics are favored for their relatively low power draw compared with longer-reach modules. In high-density rows—particularly when every slot is populated—thermal headroom becomes just as critical as port count. Using short-range 850 nm modules helps maintain airflow targets and power budgets while delivering full 10 Gbps performance.

Deployment Architecture Patterns for 10GBASE-SR

Designing around SR modules requires attention to cabling topology, patching density, channel loss, and future migration paths. The subsections below provide prescriptive patterns that work well in both greenfield and brownfield environments.

Leaf/Spine and Clos Fabric Uplinks

In a leaf/spine architecture, 10 GbE SR optics are commonly used for server access and sometimes for leaf-to-spine uplinks when distances are modest. Where spine uplinks approach 100 m or when oversubscription is low, SR remains viable and cost-effective. For longer spine distances or when cabling traverses pathways with limited MMF availability, plan for LR single-mode on those particular links while keeping SR at the access layer.

Channel Design Recommendations

• Target two or fewer mated pairs per channel when the design goal is near-maximum SR reach.
• Use structured cabling with patch panels to simplify moves/adds/changes, but keep panel counts tight to control insertion loss.
• Favor OM4 trunks for new builds to extend design headroom and improve future reuse with 25G/40G/100G SR variants.
• Label both ends of every duplex to reduce operational errors, especially in mixed-speed racks.

Top-of-Rack (ToR) Server Access

SR optics are ideal for connecting servers to their ToR switch when fiber is preferred over copper. Typical motivations include tighter bend radii, cleaner cable dressing, reduced electromagnetic interference (EMI), and the need to route links through crowded trays where twinax DAC stiffness is a liability. The Cisco 10-3105-02 provides the simplicity and reliability needed in these dense server bays, supporting predictable, uniform cabling across different vendors’ NICs and switch ports that accept Cisco-compatible 10GBASE-SR modules.

Aggregation and Inter-Closet Links

Many enterprise buildings already host OM3/OM4 cabling between IDFs. Deploying the Cisco 10-3105-02 into these fiber paths can unlock immediate 10 GbE upgrades without re-pulling cable. Verify link length, connector count, and cleanliness to ensure the installed base meets SR link budgets; when in doubt, clean and test both ends before turn-up.

Physical Layer Best Practices for LC/PC Multimode

The physical plant is commonly the difference between a plug-and-play project and an extended troubleshooting session. Even though 10GBASE-SR is forgiving compared with long-haul optics, the following practices will improve first-time-right outcomes.

Connector Care, Cleaning, and Inspection

Always protect LC ferrules with dust caps when not in use. Before mating any connector, inspect with a scope and clean if necessary using dry, lint-free cleaning tools. Repeat the process for both ends of the channel—including any intermediate panels. Contamination or residue can introduce insertion loss and back reflection, degrading receive power and signal integrity. A preventive cleaning routine is faster than reactive remediation after a link fails.

Bend Radius and Pathway Management

Respect the minimum bend radius of duplex patch cords and trunk cables. Avoid tightly cinched Velcro ties; use multiple loose ties instead of a single tight one. In ladder racks and underfloor trays, route MMF away from high-heat zones and power feeds to reduce thermal stress. Where fiber trays are congested, stagger patch lengths to create smooth cable waterfalls toward the switch ports and prevent pinch points that can create micro-bends.

Insertion Loss and Link Budget Awareness

10GBASE-SR offers a modest link budget, so each mated pair matters. Keep a running tally of expected losses per connector and per splice in your channel documentation, then compare with optical test results. When design distances are near the SR limits for a given OM grade, favor fewer panels and premium components rated for low insertion loss.

Performance Considerations: Throughput, Latency, and Reliability

At the MAC layer, 10GBASE-SR delivers full-duplex 10 Gbps line rate. Real-world throughput is shaped by switch silicon, NIC offloads, jumbo-frame configuration, and upstream buffering policies. From a physical standpoint, SR optics add negligible latency—on the order of nanoseconds for the optical conversion—so end-to-end delay is dominated by switching and queuing. Reliability depends primarily on fiber plant quality, ambient temperatures, and adherence to handling practices.

Jumbo Frames and Application Headroom

Many data center designs enable jumbo frames (e.g., MTU 9000) to improve efficiency for storage and virtualization traffic. SR optics readily support jumbo frames; ensure both ends of the link and any intermediate VLAN bridges are configured consistently to avoid fragmentation or drops.

Link Flaps and Troubleshooting Workflow

If a link intermittently flaps, isolate layers methodically:

1. Check DOM/Telemetry: Review RX/TX power and temperature. Sudden dips often correlate with a marginal patch cord or dirty connector.
2. Swap Patch Leads: Replace the duplex jumper at one end and retest; then replace the other end if symptoms persist.
3. Loopback Test: Use an optical loopback at the switch or NIC to validate the local port and transceiver independent of the far end.
4. Replace Optic: Insert a known-good 10-3105-02 module to rule out an out-of-tolerance transmitter.
5. Test Fiber Plant: Measure insertion loss with a light source and power meter; inspect connectors and pigtails throughout the channel.

Compatibility Notes and Platform Integration

The Cisco 10-3105-02 is engineered for use in Cisco platforms offering 10 GbE short-reach optical ports. Always match the optic form factor to your equipment’s cages (for example, SFP+, X2, XENPAK, or other depending on platform generation), ensure that the network OS release supports the optic, and confirm that the remote end uses a standards-compliant 10GBASE-SR module. Interoperability is generally straightforward when both sides adhere to IEEE 802.3ae specifications and MSA behaviors, but platform software may restrict unsupported third-party optics or require administrative commands to enable them.

Mix-and-Match with Other 10 GbE Media

It is common to mix SR optics with DACs and LR optics within the same switch. SR links can terminate on patch panels and structured cabling, while DACs handle ultra-short intra-rack hops to reduce optic count. Longer inter-building or inter-row runs can use LR single-mode optics on dedicated ports. Document every media type and color-code jumpers where practical to help technicians avoid cross-patching between MMF and SMF infrastructure.

Color Conventions

• Aqua jacket: Often used for OM3/OM4 MMF patch cords supporting 10GBASE-SR and higher multimode speeds.
• Violet/Lime: Sometimes indicate OM4+ or OM5; check local standards and label clearly.
• Yellow jacket: Typically single-mode; keep separate from MMF to avoid accidental mismatch.

Cabling Plant Planning for 10GBASE-SR at Scale

Scaling from a handful of SR links to thousands introduces new considerations. Beyond link budget math, operators must account for operations workflows, spare strategies, and growth paths to 25/40/100 Gbps.

Spare Strategy and Lifecycle Management

Keep a structured spare pool for SR optics distributed across data halls and wiring closets. A common ratio is 3–5% spares for the total installed base, adjusted for lead time and vendor maintenance contracts. Implement RMA procedures and an optics quarantine shelf for modules removed due to suspected faults; label quarantine items with the port, time, and observed symptoms to support failure analysis.

Documentation and Port Mapping

Accurate documentation eliminates guesswork during incidents. Maintain a live map of patch panel positions, fiber routes, and switch port assignments. Tag each link with unique IDs at both ends. Where supported, integrate DOM telemetry into your NMS/monitoring stack and tie alerts to the documented path so that an RX power alarm automatically identifies its physical route for on-site technicians.

Migration Pathways: From 10GBASE-SR to Higher Speeds

Choosing OM4 or OM5 trunking at the outset makes later transitions smoother. 25G SR, 40G SR4, and 100G SR4/SR10 families can reuse multimode infrastructure with MPO-to-LC breakouts or trunk upgrades, depending on the target topology. When planning for future 25G or 100G, minimize connector counts and choose components rated for tighter insertion-loss budgets to preserve headroom.

Quality Assurance: Testing, Certification, and Acceptance

A disciplined test plan turns installation confidence into operational certainty. Before accepting a build, verify physical and logical parameters thoroughly.

Optical Certification Checklist

• Visual Inspection: Inspect and clean all LC connectors; document pre- and post-clean scope images when possible.
• Loss Testing: Measure insertion loss end-to-end at 850 nm; compare against design thresholds and vendor recommendations.
• Continuity and Polarity: Confirm A-to-B polarity for duplex LC; correct any crossed pairs or mislabeled paths.

Turn-Up and Burn-In

After optics insertion and cabling, enable the ports and confirm link status and DOM readings. Perform burn-in traffic using line-rate test tools or production traffic simulation, ideally with jumbo frames and mixed packet sizes. Monitor for CRC errors, drops, and latency spikes. If any anomalies present, isolate using the swap-and-test method described earlier.

Environmental and Mechanical Considerations

SR optics are generally robust across typical data center and enterprise ranges. Still, environmental discipline protects performance and lifespan.

Temperature and Airflow

Ensure switch intake temperatures adhere to platform specifications; optics sit on the thermal path and can experience higher local temperatures than the ambient intake. Leave sufficient clearance for fiber bends; crowded bundles immediately in front of port cages can impede airflow and raise component temperatures. Use angled LC connectors or right-angle strain reliefs where appropriate to relieve stress and improve cooling.

Vibration and Handling

While typical office environments pose little risk, mobile racks and seismic-rated spaces may require additional strain relief. Avoid pulling on the fiber to remove the module; always use the module’s bail latch. Store removed optics in anti-static clamshells with dust caps secured.

Security, Compliance, and Operations Governance

Optics themselves don’t process user data, but physical-layer hygiene and secure operations are still relevant. Inventory control prevents loss, and change-management rigor ensures that moves/adds/changes are audited and reversible.

Asset Tracking

Track each Cisco 10-3105-02 module by serial number. Associate it with its switch slot/port and the circuit ID. This mapping supports rapid RMA and root-cause analysis and helps reconcile stock during audits. Some operators serialize patch cords too, particularly in regulated environments where chain-of-custody matters.

Change Windows and Rollback Plans

Even with hot-swappable SR optics, schedule migrations and bulk turn-ups during maintenance windows appropriate to the affected services. Prepare a simple rollback: retain the previous optic or cable route until validation completes. Document the pre-change and post-change DOM readings for a trustworthy audit trail.

Cost Optimization: Balancing CapEx and OpEx

Short-range optics are one of the most budget-friendly paths to 10 GbE. Savings compound when standardized across a fleet and when the MMF plant is reusable for future generations. Consider the following levers:

Standardize on OM4 for New Pulls

While OM3 supports many SR deployments, OM4 extends distance and boosts signal margins for higher-speed upgrades. The incremental cable cost is usually offset by operational flexibility and risk reduction across the lifecycle of the build.

Right-Sizing Patch Lengths

Stocking a rational set of patch lengths—e.g., 1 m, 2 m, 3 m, 5 m—prevents slack coils that clutter the front of racks. Shorter, purpose-fit jumpers improve airflow and aesthetics and reduce accidental disconnection risk during maintenance.

Optics Pooling Across Environments

Consolidate procurement to a single SR module type when possible. Shared spares between the data center and campus reduce inventory overhead and speed time-to-repair. Confirm that the chosen SR optics are supported across your switch families to avoid fragmentation.

Turning Up a Cisco 10-3105-02 10GBASE-SR Link

1. Validate Design Inputs

• Confirm link distance, number of mated pairs, and fiber grade (OM2/OM3/OM4/OM5).
• Check switch and NIC software versions for optic support.
• Ensure the far end is equipped with a standards-compliant 10 GbE SR module using LC/PC connectors.

2. Prepare the Physical Plant

• Inspect and clean LC connectors using appropriate tools.
• Verify polarity (A-to-B) and that patch cords match the intended media type.
• Route cables with proper bend radius and strain relief.

3. Insert Optics and Patch

• Insert the Cisco 10-3105-02 into the intended cage; secure the bail latch.
• Patch the duplex LC connectors (TX to RX, RX to TX) at each end.
• Label both ends of the link with matching circuit IDs.

4. Enable and Verify

• Bring the port administratively up and confirm link status.
• Check DOM readings for expected temperature and power levels.
• Run throughput tests or apply production traffic and monitor counters.

5. Document and Baseline

• Record DOM values, optical loss results, and port configuration.
• Attach scope images (if captured) to the circuit record for future reference.

Design Examples for Common Environments

Enterprise Campus: MDF to IDF

A headquarters facility may use OM4 trunks between an MDF core and multiple IDFs on the same floor. Each IDF switch stack uplinks to the core using pairs of Cisco 10-3105-02 modules. By keeping each channel to two mated pairs (panel at each side) and under 300 m, operators ensure strong margins. Redundant paths route through separate trays to maintain availability during maintenance or localized incidents.

Data Center Row: ToR to Aggregation

In a 40-rack row, each ToR has four 10 GbE uplinks via SR optics to an end-of-row aggregation switch. Using color-coded aqua OM4 patching and pre-terminated trunks, technicians can quickly identify links and re-patch during expansions. Ports are labeled by rack-unit (RU) coordinates; monitoring collects RX/TX power for proactive alerts if a connector degrades.

Virtualization Cluster: Host to Leaf

A cluster of hyperconverged nodes uses dual 10 GbE SR links per node—one for primary data, one for management/storage replication. Jumbo frames are enabled end-to-end. PFC/ETS are configured on higher-speed spine uplinks, but the SR access layer delivers predictable 10 GbE throughput and maintains tight optics power budgets with minimal heat.

Future-Proofing Considerations

While the Cisco 10-3105-02 10GBASE-SR module focuses on 10 GbE today, design choices can position your plant for tomorrow’s expansions.

Plan Trunk Backbones for MPO

If higher-speed uplinks are on the roadmap, choose MPO/MTP backbone trunks now and land them on LC cassettes for current SR use. Later, you can replace the cassettes with MPO-to-MPO connections for SR4 or SR10 variants at 40G/100G, minimizing re-cabling and downtime.

Keep Loss Budgets Aggressive

Design with lower than maximum allowed insertion loss. The cushion pays dividends when optics age, temperatures fluctuate, or maintenance temporarily introduces additional mated pairs. Conservative loss targets also aid future migrations that may have tighter budgets.

Embrace Telemetry

Export DOM data to your observability platform. Build dashboards that plot RX power trends and temperature histograms by device, room, and rack zone. Alerting on deviations from baselines helps catch fiber pinch points after rack moves or patch panel reorganizations.

Operational Tips for Day-2 Reliability

Labeling Discipline

Use durable, legible labels on both LC boots and panel ports. Match the naming convention in your DCIM or network source of truth. If your organization manages multiple facilities, adopt a global scheme to reduce confusion when teams support each other remotely.

Port Security and Loop Prevention

On access ports that terminate end hosts, apply appropriate security features (e.g., port security, storm control, or IEEE 802.1X in campus use) and ensure spanning-tree protections are in place where relevant. While these operate above the physical layer, a clean SR link is foundational to their effectiveness.

Spare Jumpers and Cleaning Kits On-Hand

Stock each closet and row with a small kit: several lengths of duplex OM4 jumpers, an LC cleaning pen, lint-free wipes, and a basic inspection scope. This local tooling turns a potential hours-long incident into a quick, on-site fix.

Specification Highlights and Planning Aids

While exact specifications can vary by platform and revision, the following planning highlights reflect common expectations for a Cisco-class 10GBASE-SR transceiver using LC/PC multimode interfaces:

• Data Rate: 10 Gbps, full duplex.
• Wavelength: 850 nm nominal.
• Connector: Duplex LC/PC.
• Fiber Type: 50/125 µm multimode (OM3/OM4 recommended; OM2 for short runs).
• Reach Targets: Commonly up to ≈ 300 m on OM3 and ≈ 400 m (≈ 1310 ft) on OM4 under ideal conditions.
• Diagnostics: DOM/DDM support (TX/RX power, temperature, voltage).
• Hot-Swap: Yes; tool-less insertion/removal.
• Power: Low consumption suitable for high-density environments.
• Operating Environment: Typical commercial temperature ranges; confirm platform-specific limits.

Optimizing Structured Cabling for 10-Gig SR

Structured cabling is the backbone of reliable SR deployments. By treating fiber not as an afterthought but as a planned system, operators can increase uptime and reduce MTTR.

Trunk and Patch Architecture

Start with OM4 trunks between spaces (MDF ↔ IDF, row ↔ row). Land the trunks on LC panels or on MPO cassettes that break out to LC. From there, short duplex jumpers connect to active gear. Keep lengths appropriate; the goal is to avoid slack loops that obstruct ports. Where trunks must pass through high-vibration zones or tight conduits, spec bend-insensitive variants and armored options if needed.

Loss Budget Example

Consider a 280 m OM4 link with two panels (one in each room) and one patch cord at each end. Using low-loss components, the channel might include four mated pairs. If each mated pair contributes roughly 0.2 dB and the fiber contributes about 0.8 dB total over the run, the entire channel could sit comfortably within the SR budget. Measure the actual values; component tolerances vary, and clean ferrules often perform better than catalog worst-case numbers.

Operational Playbooks for Common Incidents

Incident: Link Down After Move

During rack relocations, a previously healthy SR link fails to come up. First, verify polarity—cables may have been reinserted TX-to-TX by mistake. Then, inspect and clean connectors; dust introduced during rerouting is a frequent culprit. If DOM shows good TX but no RX, swap the far-end patch cord. Finally, test with a loopback to isolate the optic versus plant.

Incident: High CRCs but Link Stays Up

Intermittent CRC errors indicate marginal signal integrity. Inspect for tight bends, crushed cable bundles, or connectors not fully seated. Check DOM for temperature spikes (blocked airflow). Replace jumpers with new, factory-cleaned cords and retest. If issues persist, certify the link with a meter and investigate panel adapters for wear.

Incident: Distance Upgrade Fails

Extending a link to a new closet pushes the design toward the edge of SR reach. If the link won’t stabilize, reduce connector count by bypassing intermediate panels, or re-pull with OM4 if you’re on OM3. As a last resort for that path, consider a single-mode LR pair for the extended segment.

Putting It All Together for High-Density 10 GbE

The Cisco 10-3105-02 10GBASE-SR LC/PC multimode 850 nm transceiver module provides a dependable foundation for short-range 10 GbE connectivity in modern networks. By pairing best-practice cabling, disciplined cleanliness, and proactive telemetry with this class of optic, organizations achieve consistent performance, scalable density, and operational simplicity. Align your cabling standards to OM4, keep connector counts low, document meticulously, and you will realize the full value of SR optics across access, aggregation, and campus domains.

Additional Compatibility and Procurement

Always consult your platform’s hardware compatibility listings to confirm support for specific transceiver PIDs and revisions. When building a bill of materials, include adequate spares, cleaning tools, and a labeling kit. Where SLAs are stringent, deploy redundant paths using separate cable routes and diverse panels to eliminate single points of failure. Lastly, train all hands—network engineers and facilities staff alike—on proper fiber handling so every touch respects the integrity of your SR plant.