The Cisco ASR 920 Series is a temperature-hardened, high-throughput aggregation router for wireline access, mobile backhaul, broadband access, and Metro Ethernet deployments. It combines Layer 2 switching, Layer 3 routing, MPLS-based L2VPN and L3VPN services, Carrier Ethernet operations, synchronization, modular interface options, and redundant AC or DC power in compact 1RU and 1.5RU chassis.
Product positioning and deployment role
The ASR 920 is intended for locations where a full-featured aggregation platform is required but rack space, environmental control, and power availability are limited. Typical placements include:
- Mobile backhaul aggregation sites
- Small-cell aggregation and transport locations
- Broadband access and subscriber aggregation networks
- Metro Ethernet remote access sites
- Central offices and smaller aggregation facilities
- Business services deployments requiring Gigabit Ethernet or 10 Gigabit Ethernet
- Remote or outside-plant cabinets with extended temperature requirements
- Legacy TDM aggregation locations requiring T1, E1, OC-3, STM-1, OC-12, or STM-4 interfaces
The platform supports Ethernet interfaces from 10 Mbps through 10 Gbps. Selected models also support TDM interface modules for PDH, SDH, and SONET services. Interface modules, power supplies, and fan trays are field-replaceable.
The ASR 920 runs Cisco IOS XE Software, a modular operating system designed for modular packaging, feature delivery, and resiliency. Cisco Prime for Evolved Programmable Network architectures is identified as a supported network management environment for service design, provisioning, assurance, and performance analysis.
Service capabilities
The platform supports MPLS in the access layer, allowing service providers to extend a common MPLS control plane toward the network edge. Supported service functions include:
- Layer 2 VPN
- Layer 3 VPN
- Virtual Private LAN Services
- Hierarchical VPLS
- Full-mesh VPLS
- Multicast services
- Carrier Ethernet transport
- Ethernet OAM
- MPLS OAM
- Layer 2 Connectivity Fault Management
- IP Service-Level Agreements
- Access Control Lists
- Per-traffic-class metering
- Bidirectional packet and byte statistics
The Carrier Ethernet ASIC is designed to provide line-rate packet processing while applying complex functions such as ACL and hierarchical QoS. The datasheet identifies support for up to eight queues per service, three scheduling levels, and buffer volumes intended for wireline and wireless applications.
The platform can be used for premium services with differentiated service-level agreements. Each service can receive distinct QoS and security attributes, allowing traffic treatment to be aligned with customer, application, or transport requirements.
Mobile backhaul and synchronization
For mobile access networks, the ASR 920 can aggregate multiple base stations through Ethernet and IP interfaces and transport the traffic using MPLS. Timing functions include:
- Synchronous Ethernet
- Ethernet Synchronization Messaging Channel
- Synchronization Status Messages
- IEEE 1588
- GNSS receiver on supported models
The ASR-920-12SZ-IM and ASR-920-12SZ-IM-CC include a built-in GNSS receiver that can operate as a grandmaster clock for small-cell aggregation and backhaul. The same model family supports Cisco Universal Power over Ethernet for powering small-cell radios.
The synchronization capabilities are relevant when mobile backhaul design requires traceable clock-source selection, Ethernet-based frequency distribution, or packet-based timing. Presales validation should identify the required timing hierarchy, reference sources, holdover expectations, interface timing mode, and applicable optical or TDM constraints before selecting the chassis.
Model selection matrix
| SKU | Hardware description | Key interfaces or characteristics | Physical form | Best For |
|---|---|---|---|---|
| ASR-920-12SZ-IM | 12 Gigabit Ethernet and 4 10GE interfaces with one interface-module slot | Supports selected Ethernet, TDM, SONET, SDH, and optical interface modules; built-in GNSS and UPOE support identified for this model family | 1RU | Mobile backhaul, small-cell aggregation, mixed Ethernet and legacy transport |
| ASR-920-12SZ-IM-CC | Conformal-coated version of the 12GE and 4-10GE platform with one interface-module slot | Intended for deployments requiring conformal-coated hardware; supports the same identified interface-module family | 1RU | Harsh or remote environments where conformal-coated hardware is required |
| ASR-920-24SZ-M | 24 Gigabit Ethernet copper interfaces and 4 10GE interfaces with modular power supplies | Fixed high-density copper aggregation platform | 1RU | Metro Ethernet and business access using copper Gigabit Ethernet |
| ASR-920-24TZ-M | 24 Gigabit Ethernet fiber interfaces and 4 10GE interfaces with modular power supplies | Fixed high-density fiber aggregation platform | 1RU | Fiber-based Metro Ethernet and remote aggregation |
| ASR-920-24SZ-IM | 24 Gigabit Ethernet and 4 10GE interfaces with modular power supplies and an interface-module slot | Supports Ethernet and selected TDM, SONET, SDH, and optical modules | 1.5RU with interface module | Sites requiring high Ethernet density plus modular legacy or transport interfaces |
| ASR-920-24SZ-M-BB | Major line bundle associated with the ASR-920-24SZ-M family | Described as a small bandwidth capacity bundle that includes ASR-920-12SZ-IM, ASR-920-12SZ-M, and ASR-920-24SZ-M | Depends on selected included platform | Standardized procurement or staged deployment across multiple ASR 920 configurations |
The datasheet also lists ASR-920-12SZ-M within the bundle description, but does not provide a separate system specification entry for that SKU in the supplied hardware table. It should therefore be treated as a bundle component rather than sized from the standalone physical and power tables.
Interface modules and compatibility
The interface-module options are concentrated on the ASR-920-12SZ-IM, ASR-920-12SZ-IM-CC, and ASR-920-24SZ-IM platforms.
| Part number | Description | Supported platform scope | Presales use |
|---|---|---|---|
| A900-IMA8T | 8-port 10/100/1000 Ethernet interface module | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | Copper Ethernet expansion |
| A900-IMA8S | 8-port SFP Gigabit Ethernet interface module | ASR-920-12SZ-IM family | Pluggable-optic Gigabit Ethernet expansion |
| A900-IMA8D | 8-port RJ48C T1/E1 interface module | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | Low-density legacy TDM aggregation |
| A900-IMA16D | 16-port T1/E1 interface module; requires patch panel | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | Higher-density T1/E1 aggregation |
| A900-IMA32D | 32-port T1/E1 interface module; requires patch panel | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | Maximum listed T1/E1 density |
| A900-IMA1X | 1-port 10GE XFP interface module | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | Single additional 10GE optical connection |
| A900-IMA2Z | 2-port 10GE SFP+/XFP interface module | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | Two-port 10GE expansion using SFP+ or XFP optics |
| A900-IMA8T1Z | 8-port 10/100/1000 plus 1-port 10GE combo module | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | Combined copper access and 10GE uplink |
| A900-IMA8S1Z | 8-port SFP Gigabit Ethernet plus 1-port 10GE combo module | ASR-920-12SZ-IM family | Fiber access with an integrated 10GE port |
| A900-IMA4OS | Four-port OC-3/STM-1 or one-port OC-12/STM-4 module | ASR-920-12SZ-IM family and ASR-920-24SZ-IM | SONET or SDH transport and legacy circuit migration |
Software support varies by platform and IOS XE release. For example, A900-IMA8T is listed from release 3.16.0S on the ASR-920-12SZ-IM family and from release 3.14.0S on the ASR-920-24SZ-IM. A900-IMA4OS is listed from release 3.18SP on the ASR-920-12SZ-IM family and from release 3.15.0S on the ASR-920-24SZ-IM. The selected software release must be checked against the exact chassis and module combination during solution design.
Interface-module limitations
The 8-port RJ-45 Gigabit Ethernet module uses chassis ports 16 through 23 when installed in the ASR-920-24SZ-IM, making those chassis ports unavailable.
The 8-port T1/E1 RJ48C module makes chassis ports 20 through 23 unavailable when installed in the ASR-920-24SZ-IM. The same limitation applies to the 16-port and 32-port T1/E1 modules.
The T1/E1 modules can be configured as T1 or E1 per module, but mixing T1 and E1 on the same interface module is not supported. Interfaces can be clocked from a line or internal clock source. The 16-port and 32-port modules use high-density connectors and require breakout cables and third-party patch panels.
The OC-3/STM-1 module supports four active OC-3 or STM-1 ports, or one active OC-12 or STM-4 port. It supports channelized and clear-channel functions described for OC-3, STM-1, T1, E1, and DS3 services. Per-port software licensing supports multirate operation and an incremental activation model.
Oversubscription is not supported. Higher combined interface bandwidth may be accepted in some configurations, but operation beyond the maximum interface throughput is not guaranteed. This is a central sizing rule: the sum of proposed ingress and egress traffic, interface-module traffic, and service-processing requirements must remain within the platform’s supported throughput envelope.
Optics, cabling, and accessories
The supported interface families use RJ-45, SFP, SFP+, XFP, RJ48C, and pluggable SONET or SDH optics as applicable. The supplied text refers to an ASR 920 optics matrix for exact optic compatibility. Optic selection should therefore be completed against the intended IOS XE release and interface module.
T1/E1 accessory SKUs include:
| Part number | Description | Best For |
|---|---|---|
| CABLE-16T1E1 | Cable for the 16-port T1/E1 module, 12 feet | Connecting the 16-port module to a breakout panel |
| PANEL-16-BNC | Breakout panel with 16 T1/E1 75-ohm BNC ports | 75-ohm T1/E1 presentation |
| PANEL-32-RJ48 | Breakout panel with 32 T1/E1 100/120-ohm RJ48 ports | RJ48C presentation for T1/E1 circuits |
| CABLE-32T1E1 | Cable for the 32-port T1/E1 module | Connecting the 32-port module to a breakout panel |
Rack and environmental accessories include:
| Part number | Description | Best For |
|---|---|---|
| A920-RCKMT-ETSI | ETSI rack-mount option | ETSI equipment racks |
| A920-RCKMT-19 | EIA 19-inch rack-mount option | Standard 19-inch racks |
| A920-RCKMT-23 | EIA 23-inch rack-mount option | 23-inch racks |
| A920-DRIP-TRAY | Modular ASR 920 drip tray | ASR-920-24SZ-IM installations where a modular drip tray is required |
| A900-IMA-BLANK | Type-A interface-module blank cover | Unused interface-module slot protection |
| ASR920-PWR-BLNK | Power supply blank cover | Unused power-supply position |
| ASR920-PWR-BLANK | Power supply blank cover | Unused power-supply position |
Power, redundancy, and field replacement
The chassis supports two AC or two DC power supplies. The power supplies are redundant and installed within the chassis. Available power SKUs include:
- A920-PWR400-A, 400W AC power supply
- A920-PWR400-D, 400W DC power supply
- ASR-920-PWR-A, AC power supply
- ASR-920-PWR-D, DC power supply
AC input is supported from 85 to 264 VAC, with a nominal range of 100 to 240 VAC and a frequency range of 47 to 63 Hz. DC input ranges vary by model. General ASR 920 DC input is listed as -18 to -32 VDC or -36 to -72 VDC, with nominal -24 or -48 VDC. The ASR-920-12SZ-IM and ASR-920-12SZ-IM-CC support -18 to -32 VDC or -40 to -72 VDC, with nominal -24, -48, or -60 VDC.
| Model | Typical power | Maximum power | Presales sizing note |
|---|---|---|---|
| ASR-920-12SZ-IM and ASR-920-12SZ-IM-CC | 130W without PoE | 150W | Add PoE load separately; verify power supply selection |
| ASR-920-24TZ-M | 100W | 130W | Suitable for fixed fiber aggregation with lower stated chassis consumption |
| ASR-920-24SZ-M | 110W | 145W | Size for copper interface density and selected optics |
| ASR-920-24SZ-IM | 130W | 180W | Allow for the interface module and modular chassis airflow |
No PoE budget is specified in the supplied material. The ASR-920-12SZ-IM model family is identified as supporting Cisco UPOE for small-cell radios, but a numeric PoE or UPOE power budget is not provided. A proposal should not assign a numeric PoE budget without a separate validated power table.
Physical and environmental specifications
| Model | Dimensions H x W x D | Form factor | Empty chassis weight |
|---|---|---|---|
| ASR-920-12SZ-IM and ASR-920-12SZ-IM-CC | 1.73 x 17.5 x 11.28 in; 44 x 444.5 x 286.54 mm | 1RU | 9.25 lb; 4.2 kg |
| ASR-920-24SZ-M | 1.72 x 17.5 x 10 in; 43.7 x 444.5 x 255 mm | 1RU | 8.5 lb; 3.9 kg |
| ASR-920-24TZ-M | 1.72 x 17.5 x 10 in; 43.7 x 444.5 x 255 mm | 1RU | 8.3 lb; 3.8 kg |
| ASR-920-24SZ-IM | 2.6 x 17.5 x 10.6 in; 66 x 444.5 x 270 mm | 1.5RU with interface module | 10.3 lb; 4.7 kg |
Configured weights listed in the datasheet are:
- ASR-920-12SZ-IM: 13.44 lb, or 6.1 kg, with two AC power supplies and an interface module
- ASR-920-24TZ-M: 10.5 lb, or 4.8 kg, with two AC power supplies
- ASR-920-24SZ-M: 10.5 lb, or 4.8 kg, with two AC power supplies
- ASR-920-24SZ-IM: 14.1 lb, or 6.4 kg, with two AC power supplies and an interface module
Airflow is front-to-back on the ASR-920-12SZ-IM, ASR-920-12SZ-IM-CC, ASR-920-24TZ-M, and ASR-920-24SZ-M. The ASR-920-24SZ-IM uses front-to-back and side-to-back airflow. Cabinet design must preserve the specified airflow path and provide clearance for front-panel cabling. The datasheet identifies front-panel cable access as part of the NEBS-related installation characteristics.
Operating temperature depends on altitude:
- -40 to 70 degrees C up to 1,000 feet or 300 meters
- -40 to 65 degrees C up to 6,000 feet or 1,800 meters
- -40 to 55 degrees C up to 13,000 feet or 4,000 meters
Relative humidity is 5 to 95 percent, noncondensing. Storage temperature is -40 to 70 degrees C at an altitude up to 15,000 feet or 4,570 meters. Optics may limit the applicable temperature range and must be checked independently.
Acoustic noise is a peak maximum of 55 dBA at the bystander position for rack-mounted products, except the ASR-920-12SZ-IM and ASR-920-12SZ-IM-CC, which are listed at 59 dBA. These values apply at 20 degrees C under normal operation. NEBS GR-63-Core Issue 3 sound power is listed as 78 dB at 27 degrees C. Noise may exceed these values during fan failure.
The listed MTBF values are:
| Component or model | MTBF |
|---|---|
| ASR-920-12SZ-IM and ASR-920-12SZ-IM-CC | 407,230 hours |
| ASR-920-24TZ-M | 582,610 hours |
| ASR-920-24SZ-M | 546,260 hours |
| ASR-920-24SZ-IM | 471,530 hours |
| A920-PWR400-A | 356,809 hours |
| A920-PWR400-D | 331,879 hours |
| ASR-920-FAN-TRAY | 2,811,680 hours |
| ASR-920-FAN-F | 2,581,770 hours |
| ASR-920-FAN-M | 2,681,720 hours |
| ASR-920-PWR-A | 1,598,000 hours |
| ASR-920-PWR-D | 1,129,417 hours |
Compliance and installation considerations
The platform is listed with UL, CSA, IEC, EN, and AS/NZS safety standards. Electromagnetic emissions compliance includes FCC Class A, EN55022 Class A, CISPR22 Class A, ICES-003 Class A, EN 300 386 Class A, VCCI Class A, KN22 Class A, and related power harmonic standards.
The datasheet lists immunity compliance against EN 300 386, EN 61000-6-1, CISPR24, EN 55024, EN 50121-4, and related EN/KN 61000-4 requirements.
The ASR-920-12SZ-IM is listed for IEC-61850-3 and IEEE 1613 power substation system compliance. NEBS references include GR-63-CORE, GR-1089-CORE, and SR-3580 NEBS Level 4. ETSI references include ETS/EN 300 119 Part 4, ETS/EN 300 019 environmental classes, and ETS/EN 300 753.
Network synchronization standards include ANSI T1.101, GR-1244-CORE, GR-253-CORE, ITU-T G.703, G.781, G.813, G.823, G.824, G.8261/Y.1361, G.8262, G.8264, and IEEE 1588-2008.
Presales sizing rules
- Select the chassis according to interface media first: copper Gigabit Ethernet, fiber Gigabit Ethernet, modular Ethernet, or legacy TDM.
- Keep aggregate interface bandwidth within the supported platform throughput envelope. Oversubscription is not supported.
- Treat interface-module port loss on the ASR-920-24SZ-IM as a hard design constraint.
- Do not mix T1 and E1 on a single T1/E1 interface module.
- Include breakout cables and patch panels for 16-port and 32-port T1/E1 modules.
- Validate the IOS XE release against the exact chassis, interface module, and optic combination.
- Add PoE or UPOE load separately because the supplied data gives no numeric PoE budget.
- Size AC or DC power using maximum chassis consumption, installed modules, optics, and attached powered devices.
- Confirm altitude before quoting the highest operating temperature.
- Match rack hardware to the installation environment: ETSI, 19-inch EIA, or 23-inch EIA.
- Preserve front-to-back or side-to-back airflow according to the selected chassis.
- Use the conformal-coated model and matching fan tray where the deployment requires that construction.
- Confirm optical temperature limits independently because optics can reduce the system operating range.
- For mobile backhaul, define the timing source, GNSS requirement, SyncE behavior, IEEE 1588 role, and clock distribution hierarchy.
- For TDM migration, identify impedance, connector, breakout-panel, clocking, and protocol requirements before selecting the module.
Warranty and service
The datasheet directs customers to Cisco’s Product Warranties page for warranty information. It does not state a warranty duration or a model-specific warranty entitlement.
Available service programs include implementation and support services. Total Implementation Solutions and packaged implementation services can include project management, site survey, configuration, deployment, installation, testing, cutover, training, major moves, adds and changes, design review, and product staging.
Cisco SP Base Support and Service Provider-Based Onsite Support, including packaged versions available through resellers, provide access to software updates, technical repositories, telephone support through the Technical Assistance Center, and advance replacement of hardware parts. These services are intended to support proactive or expedited problem resolution, reduce downtime, and supplement customer operational staff.
Service selection should be aligned with the deployment model, replacement logistics, geographic coverage, required software access, installation responsibility, and the operational criticality of the aggregation site.