Cisco ISR4451-X/K9 Full English Product Description

Product Overview

Core Hardware Specifications

Fixed Onboard Interfaces

• 4 × combo 10/100/1000BASE-T Gigabit Ethernet ports: each port supports RJ45 copper and SFP fiber transceivers simultaneously (4×RJ45 + 4×SFP media options for flexible LAN/WAN uplink design)Cisco
• 2 × USB 2.0 Type-A ports for zero-touch provisioning (ZTD), firmware backup, external log storage and file transfer
• Dual management console: Mini-USB Type B console + standard RJ45 serial console
• RJ45 auxiliary port for out-of-band remote maintenance via analog modem
• Front-panel LED indicators for power supply, fan health, temperature, port link status and PoE load

Expansion Slots (Key Differentiator vs ISR4431/K9)

• 3 × hot-swappable NIM (Network Interface Module) slots, fully OIR (Online Insertion and Removal) compliant; compatible with T1/E1, xDSL, serial leased lines, 4G/5G LTE cellular gateways and PoE switch modules
• 2 × single-wide SM-X enhanced service module slots (not available on ISR4431) for high-density PVDM4 voice DSP blades, ISR-WAAS WAN optimization engines, high-speed switching extensions and UCS-E compute modules
• 1 × internal ISC slot for dedicated hardware crypto acceleration engine

Split-Plane Memory & Storage

• Data Plane DRAM: 2 GB ECC DDR3 default, fixed maximum 2 GB for wire-speed packet forwarding
• Control & Services Plane DRAM: 4 GB ECC DDR3 default, expandable up to 16 GB for large routing tables, security policies, QoS queues and virtualized NFV workloads
• Industrial flash storage: 8 GB default, upgradable to maximum 32 GB for IOS XE images, local logging and virtual machine disk storageCisco

Throughput & Encryption Performance

• Baseline unlicensed aggregate multi-service throughput: 1 Gbps (6 active data plane CPU cores)
• Performance license unlocks full 2 Gbps aggregate routing throughput (all 10 data plane cores activated)
• Hardware-accelerated encrypted VPN throughput up to 1.6 Gbps, supporting massive concurrent IPsec site-to-site tunnels and SSL remote worker VPNs
• System switching fabric bandwidth exceeds 4 Gbps to eliminate forwarding bottlenecks under simultaneous firewall, NAT, IPsec, VoIP and SD-WAN mixed trafficCisco

Power & Physical Form Factor

• Form factor: 2 Rack Units (2RU), standard 19-inch rack mounting brackets included
• Dual redundant hot-swappable AC power supply support (factory ships with single AC PSU; second PSU optional for power redundancy)
• Standard AC input: 100–240 VAC auto-ranging, 47–63 Hz frequency
• Optional high-wattage PoE-capable PSU variants: up to 1000W total chassis power with 500W PoE output (redundant) or 1450W PoE boost mode without redundancy
• Physical dimensions (H × W × D): 88.9 mm × 438.15 mm × 469.9 mm
• Operating temperature range: 0°C to 40°C (32°F–104°F) for standard indoor enterprise deploymentsCisco

Integrated Functional Capabilities

1. Cisco IOS XE Native SD-WAN & Intelligent WAN (IWAN)

2. K9 Hardware-Accelerated Enterprise Security

• Dedicated AES-256 crypto engine for high-speed IPsec site-to-site VPN and SSL remote access VPN tunnels
• Zone-Based Firewall (ZBFW), embedded Firepower Next-Generation IPS, URL filtering and advanced malware threat defense
• Cisco Trustworthy Systems framework: secure boot, runtime image integrity validation, FIPS 140-2 certified crypto modules
• Application Visibility and Control (AVC/ NBAR2), Control Plane Policing (CoPP), and TrustSec group-based micro-segmentation
• Local secure internet breakout to reduce costly central data center backhaul congestion

3. Unified Communications (UC)

4. ISR-WAAS WAN Optimization

5. Edge NFV Virtualization

Software & Licensing

• Operating System: Modular, upgradeable Cisco IOS XE
• Base IP Base feature set preloaded: static routing, OSPF, EIGRP, basic NAT, ACL and hierarchical QoS functionality
• Optional subscription add-on licenses: Performance Boost, Advanced Security, Full SD-WAN, DNA Advantage, Unified Communications, ISR-WAAS Optimization
• Lifecycle status: ISR 4400 Series reached End-of-Sale on November 7, 2023; official Cisco TAC technical support terminates November 30, 2028. Recommended replacement platform: Cisco C8300 series high-performance edge routers.

Typical Deployment Use Cases

1. Large enterprise regional branch offices requiring 1 Gbps–2 Gbps multi-service throughput
2. Financial, retail chain headquarters and multi-building healthcare campuses with converged SD-WAN, voice and integrated security
3. Carrier colocation and telco remote edge sites with optional -48V DC power and NEBS compliance
4. Distributed branches running virtualized network functions, WAN optimization and high-volume encrypted VPN tunnels
5. Hybrid cloud gateway deployments with secure direct internet breakout and SaaS acceleration

Core Differentiators vs ISR4431/K9

1. 2RU chassis vs 1RU form factor, supporting dual redundant AC power supplies for high availability
2. 2 × SM-X service module slots (0 slots on ISR4431) for voice DSP, WAN optimization and switching blades
3. Higher baseline throughput: 1 Gbps base / 2 Gbps licensed vs 500 Mbps base / 1 Gbps licensed
4. Doubled encrypted VPN throughput (1.6 Gbps vs 900 Mbps) for large-scale SD-WAN deployments
5. Dual USB 2.0 ports versus single USB port on ISR4431
6. Superior concurrent multi-service processing capacity under heavy firewall, NAT, VoIP and encryption workloads