The Cisco ONS-SI-2G-L1 (ONS-SI-2G-L1 - Cisco 2.5Gb/s OC-48/STM-16 Single-Mode Fiber 40km 1310nm Duplex LC Connector SFP Transceiver Module) is a Transceiver component engineered for sustained enterprise-class workloads. This part addresses common procurement scenarios where exact-match replacement, capacity expansion, or new-build deployment is required. Technical specifications include capacity of 2.5 GB, data rate of 5 Gb/s, wavelength of 1310 nm, range of 40 km. Common deployment scenarios include data-center ToR (top-of-rack) switching, server-to-storage NAS/SAN connectivity, 10/25/40/100 GbE backbone aggregation, and edge router replacement in branch-office deployments. Pro Disk Network sources the ONS-SI-2G-L1 through reputable distribution channels and applies a verification check against the OEM compatibility matrix before each unit is added to active inventory. Each unit ships from a US fulfillment hub (Hillsboro OR, Atlanta GA, or Phoenix AZ) with same-day dispatch on in-stock orders before 3pm ET. 90-day Pro Disk Network functional warranty included; free US ground shipping on orders over $150.
The ONS-SI-2G-L1 is a Cisco transceiver component with capacity 2.5 GB, data rate 5 Gb/s, wavelength 1310 nm. Pricing on the ONS-SI-2G-L1 is quote-based — email sales@prodisknetwork.com or use our live chat for a quote within one business day.
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Reviewed by:Pro Disk Network Engineering Team — . Specifications, compatibility, and pricing for the ONS-SI-2G-L1 are shown on this page.
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Same-Day US Shipping — orders before 3pm ET ship today via UPS
30-Day Returns — pre-paid label on DOA and defective items
Quick Answer: Is the ONS-SI-2G-L1 compatible with my switch?
Pro Disk Network validates every ONS-SI-2G-L1 against the target switch's published compatibility matrix before shipment. If you let us know your switch model and firmware version, we will confirm fitment and code the module appropriately (Cisco-coded, Juniper-coded, HPE-coded, etc.) at no extra charge.
How fast does the ONS-SI-2G-L1 ship?
Pro Disk Network dispatches the ONS-SI-2G-L1 same-day on orders confirmed before 3 pm ET. Multi-pallet projects requiring crating ship within 2 business days. International shipping (Canada, Mexico, EU, APAC) takes 3-7 business days via DHL Express or FedEx International Priority.
The ONS-SI-2G-L1 is deployed by US enterprises, MSPs, government, and education customers across multiple infrastructure scenarios. Below are the most common deployment patterns Pro Disk Network sees in real-world orders.
DCI (Data Center Interconnect) — Inter-DC routing or aggregation. LR4/LR8 transceivers for 10–80 km, ER4 for 40 km, ZR4 for coherent long-haul.
Campus Distribution — Catalyst-class campus distribution between IDF and MDF closets. PoE+ where wireless APs and IP phones share infrastructure.
Branch / Edge — Smaller form-factor switches and routers for branch sites. SD-WAN-compatible or static-VPN-attached as the architecture dictates.
What is the ONS-SI-2G-L1?
The ONS-SI-2G-L1 is a Cisco network interface module with capacity 2.5 GB and data rate 5 Gb/s, manufactured by Cisco. Pro Disk Network ships this part new and certified-refurbished from our US warehouse with same-day dispatch on orders placed before 3 PM ET, backed by a 30-day return guarantee.
Pros & Cons of ONS-SI-2G-L1
Pros
Same-day US shipping cuts deployment downtime
Cons
Not for hyperscale ZR coherent — different SKU family
Some vendors deprecate firmware on EOL part numbers
Mismatched optic+switch firmware can require manual override
Frequently Asked Questions about ONS-SI-2G-L1
Is the ONS-SI-2G-L1 a genuine Cisco part?
Yes. Pro Disk Network sources every ONS-SI-2G-L1 as factory-original Cisco inventory. New units arrive sealed in OEM packaging; refurbished units are pulled from decommissioned Cisco servers, surface-tested, and re-warranted by Pro Disk Network for 90 days.
Is the ONS-SI-2G-L1 compatible with my switch?
Pro Disk Network validates every ONS-SI-2G-L1 against the target switch's published compatibility matrix before shipment. If you let us know your switch model and firmware version, we will confirm fitment and code the module appropriately (Cisco-coded, Juniper-coded, HPE-coded, etc.) at no extra charge.
How fast does the ONS-SI-2G-L1 ship?
Pro Disk Network dispatches the ONS-SI-2G-L1 same-day on orders confirmed before 3 pm ET. Multi-pallet projects requiring crating ship within 2 business days. International shipping (Canada, Mexico, EU, APAC) takes 3-7 business days via DHL Express or FedEx International Priority.
What is the warranty on the ONS-SI-2G-L1?
New ONS-SI-2G-L1 units carry the full Cisco manufacturer warranty (typically 1 to 5 years depending on product line). Refurbished and bulk-OEM units include a Pro Disk Network advance-replacement warranty (90 days refurbished). DOA replacement is free within 30 days of receipt.
Do you offer bulk pricing for the ONS-SI-2G-L1?
Email sales@prodisknetwork.com with the quantity and target ship date for a quote within one business day.
Optic Coding, Vendor Lock-In, and Multi-Vendor Compatibility
If you are running a multi-vendor leaf-spine architecture (Arista leaves and Cisco spines, for example), order optics coded for each endpoint separately. Optics in DAC and AOC cables are factory-coded to each end and cannot be flashed in-field. Plan the coding split at design time and document it in your network drawings.
Bandwidth Sizing for Spine-Leaf, EVPN-VXLAN, and Hyperconverged Storage
Sizing network bandwidth for a leaf-spine fabric using the ONS-SI-2G-L1 starts with the workload mix. For general-purpose virtualisation, plan 10G server-to-leaf, 25G or 40G leaf-to-spine; oversubscription up to 4:1 is acceptable. For hyperconverged storage (vSAN, Ceph, Storage Spaces Direct), plan 25G server-to-leaf at minimum, 100G leaf-to-spine, oversubscription 1.5:1 maximum. East-west traffic dominates in HCI clusters and starves on oversubscribed fabrics.