ISR4451-X-AXV/K9 Integrated Router for Video, Voice, and SD-WAN
Product Overview
The Cisco ISR4451-X-AXV/K9 is a high-performance Integrated
Services Router from the ISR 4000 Series that combines WAN routing,
advanced voice, and application experience services in a single
platform. This model includes AX (Application Experience) and UC
(Unified Communications/Voice) feature licenses, making it ideal
for large branch offices or enterprise environments requiring
secure, converged voice and data networks with QoS, SBC, and video
collaboration capabilities.
Product Details
| Specification | Description |
|---|---|
| Product Code | ISR4451-X-AXV/K9 |
| Series | Cisco ISR 4000 Series |
| Form Factor | 2RU rack-mountable |
| Performance | Base: 1 Gbps (upgradable to 2 Gbps via license) |
| Integrated Ports | 4 x 1G RJ45, 1 x Console, 1 x USB |
| NIM Slots | 3 x Network Interface Module slots |
| SM Slots | 2 x Service Module slots |
| DRAM | 4 GB (expandable up to 16 GB) |
| Flash Storage | 8 GB (expandable) |
| Power Supply | Optional dual redundant AC/DC |
| Software | Cisco IOS XE |
| License Features | AX (Application Experience), UC (Voice/Video) |
| Voice/Collaboration | Yes – SBC, CUBE, SRST, Voice Gateway |
| Security Features | IPsec VPN, ZBFW, SSL VPN, CPPr |
| SD-WAN Support | Yes (with IOS XE SD-WAN image) |
| High Availability | NSF, ISSU, dual PSU and fan supported |
Product Features
Includes AX (Application Experience): performance routing, AVC, PfR, WAAS, DPI
Includes UC/Voice license: supports CUBE, SRST, TDM voice, voice gateway functions
Supports Cisco SD-WAN, policy-based routing, and real-time traffic optimization
Modular expansion with 3 NIM slots and 2 SM slots for LTE, DSL, switch, voice, or storage
Dual power supply option for enterprise-class redundancy
Designed for secure multi-service branches, converged WAN + voice deployments
Unified platform for IP telephony, video conferencing, and advanced data services
Similar Models Comparison
| Model | Performance Range | Key Licenses Included | Voice/UC Support | SD-WAN Ready | Form Factor |
|---|---|---|---|---|---|
| ISR4451-X-AXV/K9 | 1–2 Gbps | AX + UC | Yes | Yes | 2RU |
| ISR4451-X-SEC/K9 | 1–2 Gbps | SEC (Security) | No | Yes | 2RU |
| ISR4431-AX/K9 | 500 Mbps–1 Gbps | AX only | No | Yes | 1RU |
| ISR4351-AXV/K9 | 200–400 Mbps | AX + UC | Yes | Yes | 2RU |
Latest ISR 4000 Series Models with Voice/UC Support
| Model | Voice License | Max Performance | Best For |
|---|---|---|---|
| ISR4451-X-AXV/K9 | Yes | 2 Gbps | Large branch with voice/video + SD-WAN |
| ISR4351-AXV/K9 | Yes | 400 Mbps | Medium branch with UC + data |
| ISR4331-AXV/K9 | Yes | 300 Mbps | Small branch unified communication |








