Cisco ISR4331/K9 4331 Integrated Services Router

The Cisco ISR4331/K9 4331 Integrated Services Router is a high-performance, modular networking solution designed for branch offices that require secure, scalable, and application-aware services. With a multicore CPU architecture and Cisco IOS XE Software, the ISR4331 delivers intelligent services such as voice, video, security, and WAN optimization—without sacrificing performance. Built to handle growing network demands, this router enables cloud integration, encrypted traffic inspection, and application visibility, while maintaining high availability and service agility.

Product Features

Multicore CPU with Modular Cisco IOS XE

Designed with a multicore processor and modular software architecture, the ISR4331 separates control, data, and services planes for consistent high performance and efficient multitasking across a wide range of network functions.

High Throughput for Branch Environments

Offers 100 to 300 Mbps system throughput, ensuring reliable performance under concurrent service loads such as voice, security, and WAN optimization—ideal for high-speed WAN deployments.

Integrated Voice and Video Services

Supports analog and digital voice modules with up to 12 ports (FXS, FXO, BRI, E/M), enabling seamless integration of telephony, call processing, and video communication within the same platform.

Advanced Security and Threat Defense

Includes encryption acceleration, firewall capabilities, intrusion prevention, and support for Cisco TrustSec for consistent policy enforcement and secure VPN connectivity with FlexVPN and DMVPN.

Application Visibility and Optimization

Features NBAR2 and Performance Routing (PfR) for application-level traffic monitoring, control, and route optimization. WAN optimization with ISR-WAAS or virtual WAAS improves performance for remote users and cloud applications.

Scalable and Modular Design

Supports up to two Network Interface Modules (NIM), one single-wide Service Module (SM), and one PVDM4 slot for DSPs. Easily upgradeable to meet expanding business needs without replacing the chassis.

Cloud-Ready Architecture

Enables agile service deployment and centralized management through cloud platforms. Includes capabilities such as Cisco UCS E-Series server virtualization and intelligent WAN (IWAN) features for branch transformation.

Product Specifications

• Model: Cisco ISR4331/K9
• Form factor: 1U rackmount
• WAN interfaces: 1 Gigabit Ethernet, 1 Gigabit Ethernet/SFP combo port, 1 SFP port
• LAN ports: 2 integrated GE ports
• Management port: 1 GE
• Network Interface Modules (NIM): 2 slots
• Service Module (SM): 1 single-wide slot
• Integrated Services Card (ISC): 1 PVDM4 slot
• Default DRAM: 4 GB
• Default flash memory: 4 GB
• Performance throughput: 100 Mbps (upgradable to 300 Mbps with license)
• Voice support: Up to 12 ports (FXS, FXO, BRI, E/M)
• T1/E1 digital voice channels: Up to 360
• IPv4 routing protocols: RIP v1/v2, EIGRP, OSPF, BGP, Policy-Based Routing (PBR), PfR
• IPv6 routing: EIGRP, RIPng, OSPFv3, IS-IS, BGP, PBR
• Multicast protocols: PIM-SM, static multicast routing, MLD
• Security features: VPN (IPsec, SSL, DMVPN, FlexVPN), firewall, IPS, NAT, TrustSec
• Application services: AVC, NBAR2, Performance Agent
• QoS capabilities: HQoS, CBWFQ, LLQ, shaping, policing
• WAN optimization: Integrated WAAS and virtual WAAS (vWAAS)
• Virtualization: Supports UCS E-Series modules
• Power over Ethernet (PoE) support: Up to 530W with PoE Boost
• Package dimensions: 23.1 x 23.0 x 6.9 inches
• Package weight: 19.3 lbs