Sourced for enterprise IT teams, the WD NTK591LH (NTK591LH - Nortel 1Gb/s 1000Base-CWDM Single-Mode Fiber 120km 1470nm LC Connector SFP Transceiver Module) is a Transceiver component appropriate for new-build, expansion, or warranty-replacement procurement. Technical specifications include capacity of 1 GB, data rate of 1 Gb/s, wavelength of 1470 nm, range of 120 km. Appropriate for enterprise core-aggregation tier, hyperscale leaf-spine fabric expansion, EVE-NG / GNS3 lab environments at scale, and matched-pair high-availability switching deployments. Pro Disk Network supplies the NTK591LH to US business buyers. Stocked units ship same-day on in-stock orders placed before 3pm ET. Pro Disk Network applies a 90-day functional warranty. Free US ground shipping on orders over $150; same-day expedited (UPS Next Day Air, FedEx Priority) available at checkout.
The NTK591LH is a WD transceiver component with capacity 1 GB, data rate 1 Gb/s, wavelength 1470 nm. Pro Disk Network sells the NTK591LH for $502.20 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 NTK591LH are shown on this page.
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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 NTK591LH compatible with my switch?
Pro Disk Network validates every NTK591LH 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 NTK591LH ship?
If in stock, the NTK591LH 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 NTK591LH 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 NTK591LH?
The NTK591LH is a WD network interface module with capacity 1 GB and data rate 1 Gb/s, manufactured by WD. 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 NTK591LH
Pros
Same-day US shipping cuts deployment downtime
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 NTK591LH
Is the NTK591LH a genuine WD part?
Yes. Pro Disk Network sources every NTK591LH as factory-original WD inventory. New units arrive sealed in OEM packaging; refurbished units are pulled from decommissioned WD servers, surface-tested, and re-warranted by Pro Disk Network for 90 days.
Is the NTK591LH compatible with my switch?
Pro Disk Network validates every NTK591LH 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 NTK591LH ship?
If in stock, the NTK591LH 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 NTK591LH?
New NTK591LH units carry the full WD 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 NTK591LH?
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 NTK591LH 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 NTK591LH 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 NTK591LH and the connected NICs support jumbo frames — some older NICs cap at 9000-byte payloads even when jumbo-enabled.