Cisco ASR 9901 Router Capacity, 456 Gbps Fabric and 42 Ports

The Cisco ASR 9901 Router is a 2RU provider-edge platform with 456 Gbps of nonblocking, full-duplex fabric capacity, integrated routing, 42 fixed interfaces, redundant power and fan infrastructure, and Cisco IOS XR 64-bit software.

Product role and deployment fit

The ASR 9901 is part of the Cisco ASR 9000 Series and is designed for carrier Ethernet aggregation, provider-edge services, large-scale Layer 2 and Layer 3 deployments, Data Center Interconnect, and Satellite Network Virtualization System mode. It uses the same Cisco IOS XR software image as other ASR 9000 Series routers, allowing common operating procedures, feature policies, and software practices across the platform family.

The chassis combines the route processor, switching fabric, fixed Ethernet interfaces, timing interfaces, management interfaces, power modules, and fan infrastructure in a compact 2RU enclosure. The integrated RSP removes the need for a separate route processor module. The forwarding architecture is distributed, allowing ports to support independent forwarding for performance and scale.

The platform is suitable for:

• Carrier Ethernet aggregation
• Provider-edge Layer 2 and Layer 3 services
• Business Ethernet services
• L2VPN and L3VPN
• Mobile backhaul transport
• Broadband Network Gateway deployments
• Data Center Interconnect
• Segment Routing and EVPN deployments
• Network timing and synchronization services
• Satellite Network Virtualization System deployments
• Sites requiring AC or DC power options
• Deployments requiring MACsec across supported port speeds

The datasheet identifies support for Layer 2 and Layer 3 multicast, SyncE, Ethernet OAM, MPLS OAM, Layer 2 and Layer 3 ACLs, hierarchical QoS, MPLS Traffic Engineering Fast Reroute, MC-LAG, IRB, Cisco Nonstop Forwarding, and Cisco Nonstop Routing. Advanced IOS XR 64-bit capabilities include Segment Routing, EVPN, programmability, and telemetry.

Interface and forwarding architecture

The ASR 9901 has 42 integrated Ethernet ports:

The integrated interface count provides a combination of high-density 1 GE access, 1/10 GE aggregation, and 100 GE uplink connectivity. The 24 dual-rate ports are relevant when a deployment must support both existing 1 GE services and future 10 GE migration without changing the chassis.

The platform also supports Cisco pluggable interfaces across 1, 10, 40, and 100 Gigabit Ethernet interface types. The exact optic and pluggable combination must be selected from the Cisco Optics Compatibility Matrix. The fixed-port count should not be interpreted as permission to use every possible optic type simultaneously; optical reach, form factor, port speed, software support, and platform compatibility must be validated during design.

MACsec encryption is supported on all port speeds identified by the datasheet. This is relevant for carrier, enterprise interconnect, and aggregation links requiring Layer 2 link encryption without placing a separate encryption appliance in the traffic path.

The switching fabric provides up to 456 Gbps of bandwidth. It is described as nonblocking and full duplex. The integrated RSP supports this fabric capacity and runs Cisco IOS XR 64-bit software. The RSP includes 32 GB of RAM and a four-core, 2.4 GHz Intel CPU.

Timing and synchronization

Timing support is a significant design consideration for mobile backhaul and other service-provider networks. The ASR 9901 includes hardware-based IEEE 1588 support for packet-based timing services.

The chassis provides two independent clock-source connections:

• BITS
• Synchronization Supply Unit with DOCSIS Timing Interface

These connections provide redundant centralized network synchronization support. A GPS input is also provided for optional Stratum-1 clocking.

Presales sizing should identify the timing architecture before selecting the installation location. A deployment requiring GPS-based Stratum-1 timing must account for the GPS input and the associated site infrastructure. A deployment using centralized timing should document the BITS and SSU/DTI connections, source redundancy, clock priority, and failure behavior. The datasheet does not define detailed timing accuracy, holdover, antenna requirements, or synchronization profile limits.

IOS XR services and resiliency

The ASR 9901 uses Cisco IOS XR 64-bit, a carrier-class operating system intended for always-on operation. The platform supports the same software image family used by other ASR 9000 Series routers, which can reduce operational variation across a service-provider network.

Listed service and resiliency capabilities include:

• Ethernet services
• L2VPN
• IPv4
• IPv6
• L3VPN
• Layer 2 multicast
• Layer 3 multicast
• SyncE
• Ethernet OAM
• MPLS OAM
• Layer 2 ACLs
• Layer 3 ACLs
• Hierarchical QoS
• MPLS TE-FRR
• MC-LAG
• IRB
• Nonstop Forwarding
• Nonstop Routing
• Segment Routing
• EVPN
• Programmability
• Telemetry
• Satellite Network Virtualization System mode

Feature availability can depend on the selected software entitlement and chassis business model. The license matrix must therefore be reviewed alongside the traffic model and service portfolio.

Power, cooling, and hardware redundancy

The ASR 9901 supports redundant AC or DC power supplies and redundant fans. The available power supply part numbers are:

• A9K-1600W-AC
• A9K-1600W-DC

AC input is worldwide ranging from 90 to 265 volts at 50 to 60 Hz. DC input is supported from -40 to -72 volts.

Power consumption is specified as 850 watts typical and 1100 watts maximum. These values should be used for rack power, thermal, and facility calculations. The 1600 watt rating of an individual power supply is not the same as the router’s stated typical or maximum consumption. Final power engineering should account for the selected redundancy arrangement, site voltage, circuit capacity, breaker coordination, and facility derating rules.

Airflow is front to back. Rack layout must preserve unobstructed front intake and rear exhaust paths. The chassis supports three fan trays in the fully configured weight stated by the datasheet. Fan and power redundancy should be included in the installation plan, with physical clearance provided for field replacement.

The platform has an embedded USB memory port for USB flash access during software image loading and upgrades. Front-panel LEDs provide status indication for the RSP, power management, compact flash, and hard disk drive activity. Management ports provide console access.

Physical and environmental requirements

The ASR 9901 is a 2RU chassis with the following physical characteristics:

The standard nominal operating temperature is 5 to 40 degrees C. Short-term operation is specified from -5 to 55 degrees C. Storage temperature is specified as -40 to 70 degrees C in the environmental specification table. Another general environmental entry lists -40 to 75 degrees C; this discrepancy should be resolved against the applicable installation and hardware documentation before committing the unit to a storage environment.

Nominal operating relative humidity is 10 to 85 percent. Short-term operating humidity is 5 to 90 percent. Storage relative humidity is 5 to 95 percent. The humidity notes specify that water content must not exceed 0.024 kg of water per kg of dry air.

Presales installation checks should cover:

1. Two rack units of vertical space.
2. A rack depth that accommodates a 60 cm chassis plus cable bend radius and rear service clearance.
3. Support for the 25.4 kg fully configured weight.
4. Front-to-back airflow alignment with the facility cooling design.
5. AC or DC feed compatibility.
6. Site operation within nominal temperature and humidity limits.
7. Altitude impact on the installation environment.
8. Separate power feeds where supply redundancy is required.

The supplied datasheet does not specify MTBF. It also does not provide an acoustic noise value, sound power level, or sound pressure level. Acoustic planning therefore requires a separate platform environmental or installation document; no noise value should be used for facility acceptance from this datasheet alone.

Compliance and safety

The ASR 9901 is designed to meet the following NEBS requirements:

• SR-3580, NEBS Criteria Level 3
• GR-1089-CORE, NEBS EMC and safety
• GR-63-CORE, NEBS physical protection
• VZ.TPR.9205, Verizon TEEER

The listed ETSI standards include EN300 386, ETSI 300 019 storage class 1.1, transportation class 2.3, stationary use class 3.1, EN55022, EN55024, and EN50082-1/EN-61000-6-1. The datasheet identifies these ETSI items as qualification in progress.

Listed EMC compliance includes FCC Class A, ICES 003 Class A, AS/NZS 3548 Class A, CISPR 22 Class A, VCCI Class A, BSMI Class A, IEC/EN 61000-3-2, IEC/EN 61000-3-3, and EN 50121-4.

Immunity specifications include:

• Electrostatic discharge: 8 kV contact and 15 kV air
• Radiated immunity: 10 V/m
• Electrical fast transient: 2 kV power and 1 kV signal
• AC surge: 4 kV common mode and 2 kV differential mode
• Signal-port surge: 1 kV
• DC-port surge: 1 kV
• Conducted disturbance immunity: 10 Vrms
• Power-frequency magnetic field immunity: 30 A/m

Safety standards include UL/CSA/IEC/EN 60950-1, IEC/EN 60825 laser safety, ACA TS001, AS/NZS 60950, and FDA Code of Federal Regulations laser safety.

Ordering and licensing strategy

The ASR 9901 is available under both the Flexible Consumption Model and the Traditional Business Model. The Flexible Consumption Model provides a pay-as-you-grow structure, with software subscription capability and capacity additions over time. The Traditional Business Model provides chassis and upgrade licensing options, including staged fabric capacity.

Flexible Consumption Model SKUs

Traditional Business Model SKUs

Service, support, and warranty considerations

Cisco services for the ASR 9000 Series are described as a lifecycle services approach covering deployment, operation, and optimization. The service description includes methodologies, tools, processes, lab environments, post-implementation support, risk mitigation, operational excellence, performance, and high availability.

The supplied datasheet does not state a standard warranty duration, warranty coverage terms, replacement response time, advance replacement entitlement, software support level, or hardware service-level agreement. Those commercial terms must be selected and documented separately in the quotation and service contract.

The datasheet directs customers to Cisco Services for service-provider deployment support and to the Cisco Software Center for Cisco IOS software downloads. Software entitlement, feature licensing, and support coverage should be matched to the selected FCM or Traditional Business Model order.

Presales sizing rules

Use the following rules when building a bill of materials and deployment design:

1. Select the chassis business model before selecting upgrade and software license SKUs.
2. Size interfaces by service role, not only by port count. Reserve 100 GE ports for core, aggregation, or DCI roles where the traffic model requires them.
3. Confirm whether each 1/10 GE port will operate at 1 GE or 10 GE and validate optics separately.
4. Calculate fabric demand against the 456 Gbps nonblocking full-duplex capability.
5. Include both power supplies when designing for power redundancy.
6. Select AC or DC supplies based on site distribution, not chassis preference.
7. Include fan trays and the correct two-post or four-post mounting kit.
8. Match BNG, VRF, session, mobile, lawful intercept, tunnel, and nV licensing to the actual service inventory.
9. Validate environmental limits, rack depth, airflow, altitude, and fully configured weight during site acceptance.
10. Treat MTBF and acoustic noise as separate data requirements because they are not specified in this datasheet.