ISR4431 SEC K9 Integrated Services Router for Threat-Protected Branches
Product Overview
The Cisco ISR4431-SEC/K9 is a security-optimized integrated
services router designed for medium-to-large enterprise branches,
combining high-performance routing with advanced security features.
As part of the Cisco ISR 4000 Series, it supports up to 1 Gbps
throughput with scalable licensing and includes the Security (SEC)
technology package, enabling built-in support for IPsec VPN,
firewall, threat defense, and application control. It’s SD-WAN
ready and ideal for secure WAN edge deployments.
Product Details
| Specification | Description |
|---|---|
| Product Code | ISR4431-SEC/K9 |
| Series | Cisco ISR 4000 Series |
| Form Factor | 1RU Rack-Mountable |
| Default Throughput | 500 Mbps (boostable up to 1 Gbps via license) |
| Processor | Cisco QuantumFlow Processor |
| System Memory (DRAM) | 4 GB (expandable to 16 GB) |
| Flash Storage | 8 GB (expandable to 32 GB) |
| Integrated Interfaces | 3 x 1G RJ45 + 1 x 1G SFP |
| NIM Slots | 2 |
| SM-X Slots | 1 |
| Voice Support | Optional with additional licensing |
| Security Package Included | Yes (SEC license pre-installed) |
| Redundant Power Supply | Optional external RPS support |
| Software | Cisco IOS XE with SD-WAN and Security features |
| Virtualization | Supports KVM, UCS-E, and containerized applications |
Product Features
Includes SEC technology license for IPsec VPN, ZBFW, and advanced packet inspection
Performance-on-demand licensing scales throughput from 500 Mbps to 1 Gbps
SD-WAN ready, supporting application-aware routing and centralized control
Cisco IOS XE provides programmability, automation, and cloud readiness
Supports application visibility and control (AVC) with QoS and NetFlow
Optional voice services via DSP modules and Unified Communications license
Ideal for secure branch edge, cloud access, and MPLS WAN environments
Similar Models Comparison
| Model | Security License | Max Throughput | NIM Slots | SD-WAN | Form Factor | Ideal Use Case |
|---|---|---|---|---|---|---|
| ISR4451-X-SEC/K9 | Yes | 2 Gbps | 3 | Yes | 2RU | Large secure branches |
| ISR4431-SEC/K9 | Yes | 1 Gbps | 2 | Yes | 1RU | Medium secure branch |
| ISR4351-SEC/K9 | Yes | 400 Mbps | 2 | Yes | 1RU | Medium-to-small branches |
| ISR4331-SEC/K9 | Yes | 300 Mbps | 2 | Yes | 1RU | Secure compact branch offices |
Latest ISR 4000 Series Security Models
| Model | Max Throughput | SEC License | SD-WAN | Ideal Role |
|---|---|---|---|---|
| ISR4451-X-SEC/K9 | 2 Gbps | Yes | Yes | Enterprise-class security router |
| ISR4431-SEC/K9 | 1 Gbps | Yes | Yes | Medium secure WAN edge |
| ISR4351-SEC/K9 | 400 Mbps | Yes | Yes | Secure voice/data integration |
