The TN-SFP-LXB21 (TN-SFP-LXB21 - Transition 1000Base-LX 1310nmTX/1550nmRX 20km LC 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 range of 20 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 maintains the TN-SFP-LXB21 in our enterprise inventory and verifies each unit against manufacturer datasheet specifications prior to listing. New stock ships factory-sealed where available; refurbished units are tested under load before dispatch and ship with a 90-day Pro Disk Network functional warranty. Same-day dispatch on in-stock orders placed before 3pm ET; free standard ground shipping on US orders over $150.
The TN-SFP-LXB21 is a enterprise-grade transceiver component with range 20 km. Pro Disk Network sells the TN-SFP-LXB21 for $124.51 with same-day US shipping and a 30-day return guarantee.
Reviewed By
Reviewed by:Pro Disk Network Engineering Team — . Specifications, compatibility, and pricing for the TN-SFP-LXB21 are shown on this page.
Trust Signals
US-based LLC — 7345 W Sand Lake Rd, STE 210, Office 3208, Orlando, FL 32819
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 TN-SFP-LXB21 compatible with my switch?
Pro Disk Network validates every TN-SFP-LXB21 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 TN-SFP-LXB21 ship?
If in stock, the TN-SFP-LXB21 ships same business day on US orders placed before 3 pm ET. Most US ZIP codes receive next-business-day or 2-day delivery via FedEx/UPS Ground or Express. Bulk and project orders shipping in pallets are typically dispatched within 24-48 hours.
The TN-SFP-LXB21 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.
Spine-Leaf Fabric — Top-of-rack 25G/100G aggregation between leaf and spine switches. Match speed and form factor across both endpoints.
Server Uplink — 10G/25G server-to-leaf uplink — pair with matching DAC or AOC at the host NIC to avoid optic mismatch.
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.
What is the TN-SFP-LXB21?
The TN-SFP-LXB21 is a network interface module with range 20 km, manufactured for enterprise IT deployments. 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 TN-SFP-LXB21
Pros
Matched-pair option for redundant link orders
Cabling and DAC/AOC labels clearly mark optic class
Cons
Refurbished switches may show minor rack-rail wear
Power supplies sold separately on certain SKUs
Long-haul ZR4/CFP4 modules subject to export-control screening
Frequently Asked Questions about TN-SFP-LXB21
Is the TN-SFP-LXB21 a genuine part?
Yes. Pro Disk Network sources every TN-SFP-LXB21 as factory-original inventory. New units arrive sealed in OEM packaging; refurbished units are pulled from decommissioned servers, surface-tested, and re-warranted by Pro Disk Network for 90 days.
Is the TN-SFP-LXB21 compatible with my switch?
Pro Disk Network validates every TN-SFP-LXB21 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 TN-SFP-LXB21 ship?
If in stock, the TN-SFP-LXB21 ships same business day on US orders placed before 3 pm ET. Most US ZIP codes receive next-business-day or 2-day delivery via FedEx/UPS Ground or Express. Bulk and project orders shipping in pallets are typically dispatched within 24-48 hours.
What is the warranty on the TN-SFP-LXB21?
New TN-SFP-LXB21 units carry the full 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 TN-SFP-LXB21?
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
Networking optics — SFP, SFP+, QSFP+, QSFP28 — are physically interoperable across vendors but logically restricted by firmware coding. The TN-SFP-LXB21 is coded for a specific vendor family at our factory step before shipping, which preserves the OEM warranty workflow and allows the optic to be recognised without ‘service unsupported-transceiver’ CLI overrides. Mixing third-party optics with same-vendor optics in the same chassis is safe; mixing across vendor codings sometimes triggers warnings in the switch log.
Bandwidth Sizing for Spine-Leaf, EVPN-VXLAN, and Hyperconverged Storage
For EVPN-VXLAN overlays, the TN-SFP-LXB21 carries the underlay tunnels in addition to the workload traffic. Plan for VXLAN encapsulation overhead (50 bytes) plus MTU headroom; set the underlay MTU to 9216 (jumbo frames) and the overlay MTU to 9000. Make sure both the TN-SFP-LXB21 and the connected NICs support jumbo frames — some older NICs cap at 9000-byte payloads even when jumbo-enabled.