ISR4331-AX/K9 with Deep Packet Inspection and SD-WAN
Product Overview
The Cisco ISR4331-AX/K9 is an Application Experience-enabled
Integrated Services Router from the ISR 4000 Series, designed for
small to medium enterprise branches that require advanced
application visibility, WAN optimization, and secure hybrid
connectivity. With the AX license included, the ISR4331-AX/K9
supports features such as NBAR2, AVC, PfR, and WAAS. Its base
performance of 100 Mbps, upgradable to 300 Mbps, makes it ideal for
SD-WAN, cloud-access edge, and intelligent branch routing.
Product Details
| Specification | Description |
|---|---|
| Product Code | ISR4331-AX/K9 |
| Series | Cisco ISR 4000 Series |
| Form Factor | 1RU rack-mountable |
| Base Performance | 100 Mbps (upgradable to 300 Mbps via license) |
| Built-in Interfaces | 4 x 1G RJ45, Console, USB |
| NIM Slots | 2 x Network Interface Module slots |
| SM Slots | 1 x Service Module slot |
| DRAM | 4 GB (expandable to 16 GB) |
| Flash Storage | 8 GB (expandable) |
| Power Supply | Optional dual redundant AC/DC |
| Software | Cisco IOS XE |
| AX License Features | AVC, NBAR2, WAAS, PfR, DPI |
| SD-WAN Support | Yes (via SD-WAN image) |
| Security Features | ZBFW, IPsec VPN, SSL VPN (with SEC license) |
| Application Awareness | Yes – Deep Packet Inspection and Traffic Control |
| High Availability | NSF, ISSU, hot-swappable fans, dual PSU supported |
Product Features
Includes AX license for application visibility, traffic optimization, and control
Supports NBAR2, AVC, PfR, and WAAS for advanced WAN performance
Delivers 100–300 Mbps performance, scalable by license
Modular architecture with 2 NIM and 1 SM slots for WAN, voice, or switching modules
Powered by Cisco IOS XE, enabling SD-WAN, telemetry, and automation
Ideal for hybrid WAN, cloud-first branches, and application-intelligent routing
Supports QoS, application SLA tracking, and cloud-based optimization
Similar Models Comparison
| Model | AX License | Max Performance | SD-WAN Ready | NIM/SM Slots | Form Factor |
|---|---|---|---|---|---|
| ISR4331-AX/K9 | Yes | 300 Mbps | Yes | 2 / 1 | 1RU |
| ISR4351-AX/K9 | Yes | 400 Mbps | Yes | 2 / 2 | 2RU |
| ISR4451-AX/K9 | Yes | 2 Gbps | Yes | 3 / 2 | 2RU |
| ISR4431-AX/K9 | Yes | 1 Gbps | Yes | 2 / 1 | 1RU |
Latest AX-Enabled ISR Models Comparison
| Model | Performance Range | AX Features | Target Use Case |
|---|---|---|---|
| ISR4331-AX/K9 | 100 – 300 Mbps | AVC, WAAS, PfR, NBAR2 | Small/medium branch with cloud apps |
| ISR4351-AX/K9 | 200 – 400 Mbps | Enhanced WAN optimization | Medium branch with application focus |
| ISR4451-AX/K9 | 1 – 2 Gbps | Full AX suite | Large branches, WAN + cloud edge |
