Cisco ISR4331/K9 is a modular enterprise branch router from the Cisco 4000 Series ISR family, designed for secure WAN connectivity, application services, and network convergence. It integrates routing, security, voice, and application services into a single platform, making it ideal for medium-sized branch offices and enterprise edge deployments.

The router supports performance licensing, allowing throughput upgrades from base to higher performance tiers.

? KEY FEATURES

• Integrated services: routing, security, voice, and WAN optimization
• Base throughput: 100 Mbps (upgradeable to 300 Mbps)
• Modular architecture with NIM and SM-X expansion slots
• 3 × Gigabit Ethernet ports (RJ-45 + SFP combo)
• Supports VPN, firewall, and advanced security features
• Application hosting and virtualization support
• Rack-mountable 1U enterprise platform

⚙️ TECHNICAL SPECIFICATIONS 

? Hardware Platform

• Series: Cisco 4000 Series ISR
• Model: ISR4331/K9
• Form factor: 1U rack-mount
• Architecture: Multi-core CPU with service containers

? Interfaces

• 3 × 10/100/1000 Gigabit Ethernet ports (RJ-45 & SFP combo)
• 2 × NIM (Network Interface Module) slots
• 1 × SM-X service module slot

⚡ Performance

• Default throughput: 100 Mbps
• Max throughput: 300 Mbps (with performance license)
• Multi-core CPU architecture for service scaling