Cisco ISR 4431/K9

Core Specifications

• On-board Ports:

  • 4 × 10/100/1000 GE (combo RJ‑45/SFP) for WAN or LAN router-switch.com+10router-switch.com+10cisco.com+10

• Expansion Slots:

  • 3 × Network Interface Module (NIM) slots

  • 1 × ISC slot (for PVDM voice modules) ca2-gcs.edcdn.com+5router-switch.com+5scribd.com+5router-switch.com+5cisco.com+5netmask.co+5

• Memory & Storage (default / upgradeable):

  • Flash: 8 GB (up to 32 GB)

  • DRAM Data Plane: 2 GB

  • DRAM Control Plane: 4 GB (up to 16 GB) cisco.comzpesystems.com+9netmask.co+9cisco.com+9

• Throughput:

  • 500 Mbps (default), upgradeable to 1 Gbps with Performance Licencerouter-switch.com+5router-switch.com+5router-switch.com+5

  • Boost licence can exceed 4 Gbps

• Form Factor & Interfaces:

  • 1 RU chassis

  • Management: 1 × dedicated GE OOB port, console, USB-A, USB-B cisco.com+10router-switch.com+10cisco.com+10

🔧 Features & Capabilities

• Modular Flexibility:
  Supports a variety of NIMs (e.g. T1/E1, LTE, Ethernet) with hot-swap (Online Insertion & Removal) pbtech.com+5router-switch.com+5ca2-gcs.edcdn.com+5

• Security & WAN Services:

  • Hardware-accelerated IPsec

  • Zone-based firewall

  • VRF-aware NAT

  • Supports Cisco Cloud Web Security pbtech.comrouter-switch.com+6cisco.com+6pbtech.com+6

• Power Options:
  Internal AC, PoE, DC, plus optional redundant power modules and PoE boost cisco.com+11cisco.com+11ca2-gcs.edcdn.com+11

• Management & Automation:
  Integrated with Cisco DNA Center, SD‑WAN, APIC‑EM, supports network automation and templating router-switch.com+2zpesystems.com+2pbtech.com+2

🗓️ Lifecycle Status

• End-of-Sale (EoS): 7 November 2023

• End-of-Support: 30 November 2028 itprice.com+3cisco.com+3zpesystems.com+3

• Recommended Replacement: Cisco Catalyst C8300 series (when planning future upgrades) zpesystems.com

✅ Summary Table