Lifecycle record
XR-NCS4K-521K9 EOL & EOSL Dates
Cisco NCS 4000 IOS XR Software Release 5.2.1
Lifecycle status
In EOSL Phase
XR-NCS4K-521K9 reached its last date of support on 2020-04-30. Cisco support services are no longer available for this model. Recommended replacement: XR-NCS4K-6142K9.
Last checked: 2026-06-16
EOL & EOSL Dates and Details
| End-of-Life Announcement (EOL) | 2019-01-15 |
|---|---|
| End of Sale (EOS) | 2019-04-16 |
| End of Service Life (EOSL) | 2020-04-30 |
| Manufacturer | Cisco |
| Category | Optical Transmission Network |
| Product Series | Cisco NCS 4000 |
| Part Number | XR-NCS4K-521K9 |
| Release Date | - |
| Replacement Part Number | XR-NCS4K-6142K9 |
| Replacement Product Name | Delivery of XR 6.1.42 for NCS4K |
Lifecycle Timeline
Recorded lifecycle milestones in date order.
Additional Information
Support milestones and the official source recorded for this model.
| Last Ship Date: HW, License | 2019-07-15 |
|---|---|
| End Of SW Maintenance Releases Date: HW | 2020-04-15 |
| Official EOL Notice | View Official EOL Documentation |
| End Of Phone Support: OS SW | 2020-04-15 |
More Cisco NCS 4000 EOL Dates
| Part Number | Product Name | EOL Announcement | End of Sale |
|---|---|---|---|
| E-NCS4K-6142K9 | Cisco E-delivery of XR 6.1.42 for NCS4K | 2025-06-13 | 2026-06-13 |
| E-NCS4K-651K9 | Cisco E-delivery of XR 6.5.1 for NCS4K; grants RTU license | 2025-06-13 | 2026-06-13 |
| E-NCS4K-6525K9 | Cisco E-delivery of XR 6.5.25 for NCS4K; grants RTU license | 2025-06-13 | 2026-06-13 |
| E-NCS4K-6526K9 | Cisco E-delivery of XR 6.5.26 for NCS4K; grants RTU license | 2025-06-13 | 2026-06-13 |
| E-NCS4K-652K9 | Cisco E-delivery of XR 6.5.2 for NCS4K; grants RTU license | 2025-06-13 | 2026-06-13 |
| E-NCS4K-FL6-5-26 | Cisco NCS 4K Chassis Feature Enablement License - Release 6.5.26 | 2025-06-13 | 2026-06-13 |
| NCS4009-FC-S | Cisco NCS 4009 Agnostic Cross connect - Single-chassis | 2017-12-18 | 2018-12-18 |
| NCS4016-FC-M | Cisco NCS 4016 Agnostic Cross connect - Multichassis | 2018-12-14 | 2019-12-14 |