Cisco ASR 9901 Datasheet: Expert Technical Overview

1. Product Overview

The Cisco Aggregation Services Router (ASR) 9901 is a high-performance, compact edge router designed to meet the demanding requirements of service providers and large enterprises. As part of the Cisco ASR 9000 Series, the ASR 9901 delivers carrier-grade reliability, scalability, and advanced service capabilities in a space- and power-efficient form factor. Engineered for aggregation and edge routing applications, the ASR 9901 supports a broad range of services including IP/MPLS, Carrier Ethernet, and advanced Layer 2 and Layer 3 VPNs.

The ASR 9901 is optimized for environments where space, power consumption, and operational efficiency are critical, such as metro aggregation sites, data center interconnects, and enterprise WAN edges. It integrates Cisco’s IOS XR operating system, providing modularity, high availability, and programmability to support evolving network demands and automation frameworks.

Architecturally, the ASR 9901 is a single-slot router chassis that supports a single Route Switch Processor (RSP) and multiple interface modules, enabling flexible port configurations and high throughput. It is designed to deliver up to 100 Gbps of forwarding capacity, making it suitable for high-density 10G and 100G Ethernet aggregation.

2. Product Specifications

2.1 Hardware Architecture

The ASR 9901 chassis is a compact 1 rack unit (1RU) platform that supports a single Route Switch Processor (RSP) slot and up to two interface module slots. The RSP integrates the control plane and forwarding plane functions, leveraging Cisco’s QuantumFlow Processor (QFP) technology for high-performance packet processing.

Key hardware components include:

• Route Switch Processor (RSP): Single RSP module with integrated CPU, forwarding engines, and fabric interfaces.
• Interface Modules: Support for multiple interface types including 10G, 25G, 40G, and 100G Ethernet ports via CFP2 and QSFP28 optics.
• Power Supplies: Redundant, hot-swappable AC or DC power supply options to ensure continuous operation.
• Cooling: Front-to-back airflow with redundant fans for optimal thermal management.

2.2 Performance and Capacity

The ASR 9901 delivers up to 100 Gbps of full-duplex forwarding capacity, supporting line-rate performance across all ports. The platform supports up to 48 10G ports or a combination of 10G, 25G, 40G, and 100G interfaces depending on the installed interface modules.

Packet forwarding is powered by the Cisco QuantumFlow Processor, which provides deep packet inspection, advanced QoS, and hardware-based forwarding for MPLS, IPv4, and IPv6 traffic. The router supports millions of routes and extensive MPLS label stacks, enabling complex service topologies.

2.3 Software and Protocol Support

The ASR 9901 runs Cisco IOS XR, a carrier-grade, modular operating system designed for high availability and programmability. IOS XR supports:

• Advanced routing protocols: OSPFv2/v3, IS-IS, BGP4/4+, MPLS LDP, RSVP-TE, Segment Routing (SR), EVPN
• Carrier Ethernet services: E-Line, E-LAN, E-Tree with MEF certification
• VPN technologies: Layer 2 VPN (VPLS), Layer 3 VPN (MPLS VPN), EVPN-VXLAN
• High availability features: Graceful Restart, Nonstop Forwarding (NSF), In-Service Software Upgrade (ISSU)
• Security: Control plane policing, MACsec encryption support on applicable interfaces
• Automation and programmability: NETCONF/YANG, RESTCONF, gRPC, Python scripting

2.4 Physical and Environmental Specifications

The ASR 9901 is designed for deployment in standard 19-inch racks with a 1RU height. Its compact size and low power consumption make it ideal for space-constrained environments.

3. Features and Benefits

3.1 High-Density, Flexible Interface Support

The ASR 9901 supports a wide range of interface modules, enabling service providers to tailor port configurations to specific network requirements. Whether aggregating multiple 10G Ethernet links or deploying high-capacity 100G interfaces, the platform provides flexibility without compromising performance.

3.2 Carrier-Grade Reliability and Availability

Designed for mission-critical