ISR4351-SEC/K9 Secure Integrated Services Router with VPN & AVC
Product Overview
The Cisco ISR4351-SEC/K9 is a security-enhanced integrated services
router from the Cisco ISR 4000 Series, designed for medium-sized
enterprise branches. It combines modular networking, performance
scalability, and built-in advanced security capabilities. This
model includes the Security (SEC) technology license, enabling
features such as IPsec VPN, Zone-Based Firewall (ZBFW), application
visibility, and control plane protection, with throughput scalable
from 200 Mbps to 400 Mbps.
Product Details
| Specification | Description |
|---|---|
| Product Code | ISR4351-SEC/K9 |
| Series | Cisco ISR 4000 Series |
| Form Factor | 1RU Rack-Mountable |
| Default Throughput | 200 Mbps (upgradable to 400 Mbps with license) |
| Processor | Cisco QuantumFlow Processor |
| DRAM | 4 GB (upgradable to 16 GB) |
| Flash Storage | 8 GB (upgradable to 32 GB) |
| Integrated GE Ports | 3 x 1G RJ45 + 1 x 1G SFP |
| NIM Slots | 2 |
| SM-X Slot | 1 |
| Voice Support | Optional (with DSP and UC license) |
| Security License | Included (SEC technology package) |
| Redundant Power Supply Support | Yes (external RPS optional) |
| SD-WAN Capable | Yes |
| Software | Cisco IOS XE (modular OS with programmability) |
| Virtualization | Supports UCS-E, KVM, and application containers |
Product Features
Built-in security license enables IPsec VPN, ZBFW, AVC, and threat defense
Performance-on-demand design allows cost-efficient throughput scaling
Modular slots support WAN interfaces, LTE, T1/E1, FXO/FXS, switching, and storage
Full SD-WAN support with cloud on-ramp and application-aware routing
Optional Unified Communications (SRST, CME) via voice DSPs and licenses
High resiliency and service flexibility in 1RU form factor
Ideal for secure branch connectivity, cloud access, and hybrid WAN deployments
Similar Models Comparison
| Model | Security License | Max Throughput | NIM Slots | Voice Ready | SD-WAN | Ideal Use Case |
|---|---|---|---|---|---|---|
| ISR4451-SEC/K9 | Yes | 2 Gbps | 3 | Optional | Yes | Large secure WAN branches |
| ISR4351-SEC/K9 | Yes | 400 Mbps | 2 | Optional | Yes | Medium secure branch offices |
| ISR4331-SEC/K9 | Yes | 300 Mbps | 2 | Optional | Yes | Smaller branches with security |
Latest ISR 4000 Series Security Models
| Model | Form Factor | Max Throughput | Security License | SD-WAN | Ideal Role |
|---|---|---|---|---|---|
| ISR4451-SEC/K9 | 2RU | 2 Gbps | Yes | Yes | Large-scale secure WAN |
| ISR4351-SEC/K9 | 1RU | 400 Mbps | Yes | Yes | Medium secure enterprise branch |
| ISR4331-SEC/K9 | 1RU | 300 Mbps | Yes | Yes | Compact branch with security focus |
