Cisco Router ASR 900

About the Cisco ASR 900 Series

The Cisco ASR 900 Series is Cisco's aggregation router family for service providers, utility networks and large enterprise WAN edges. It is not a branch router and it is not an edge router: the ASR 900 sits one layer in, aggregating many smaller links into a fast, redundant uplink, and it lives in an environment where an unplanned outage is measured in revenue or in customers.

That purpose explains the shape of this catalogue. A page of ASR 900 parts is not a list of boxes — it is a list of the pieces a chassis needs before it will run. The smallest items on this page are blank filler panels and rack-mount brackets; the largest are route switch processors. Buying an ASR 900 into a working state means buying a chassis, a processor, the interface modules that match your links, and enough power supplies for the redundancy you have promised your customers.

Three abbreviations recur across the part numbers and are worth learning before you compare prices:

• RSP — Route Switch Processor. The control-plane card. Without one the chassis is an empty shell; the RSP also determines the forwarding scale, which is where the large price steps on this page come from.
• IMA — Interface Module Adapter. The line cards. Each one provides the physical ports (copper, fibre, channelised optical) that face the customer links, so the IMA choice is dictated entirely by what you are connecting.
• PWR — a power supply unit. The -A and -D suffixes denote AC and DC input respectively, so on this page the same power rating appears twice at two different prices depending on the input type your site uses.

The separate A901 and ASR-920 entries are compact, fixed-configuration members of the family. They are self-contained routers rather than chassis components — a useful distinction when you are scanning a price list that mixes both.

How to Choose ASR 900 Components

1. Start from the topology, not the parts list

Unlike a fixed switch, an ASR 900 is configured to a plan. Work out three things before pricing anything here:

• How many customer links there are and what they are. Copper, Fast Ethernet, Gigabit fibre and channelised optical each map to a different IMA module, and the module is the item that must match the circuit you are terminating.
• How much forwarding capacity is needed. The route switch processor sets the scale, and the step between processors is far larger than the step between interface modules.
• What redundancy the service commitment requires. A single RSP and a single power supply is not a redundant design, whatever the chassis paper specification says.

2. Choose the processor first — it sets the ceiling on everything else

On the ASR 903 chassis, the two route switch processors differ in forwarding scale, and the price difference between them is one of the largest single decisions on this page:

• A903-RSP1A-55 — the standard-scale processor, suited to an aggregation point serving a moderate number of customer links.
• A903-RSP1B-55 — the large-scale processor. It exists for aggregation sites whose customer count or link count has outgrown the standard scale.

Note the naming: the -55 suffix denotes the licence tier in Cisco's router part number scheme (increasing tiers run -55, -76, -90). Choose the processor against the traffic you will actually carry and the features you will actually enable, because replacing it later means replacing the most expensive card in the chassis.

3. Match the interface module to the circuit, not to the port count

The IMA modules on this page are chosen by what they terminate:

• Copper Gigabit — the 8-port and 16-port Ethernet modules handle conventional customer and uplink copper.
• Fibre Gigabit — the SFP-based modules are the right answer where the run is long or the site already has fibre in place.
• Channelised optical — the optical modules terminate higher-rate optical links and subdivide them into the lower-rate services your customers buy. This is the module family that separates an aggregation router from a large switch, and it is priced accordingly.

Choosing a module with the wrong physical interface is unrecoverable — a copper module cannot be made to accept fibre — so confirm the interface type from the circuit inventory, not from the part number alone.

4. Decide the power input and the redundancy level

The same power rating is stocked for AC and DC sites, and the two are not interchangeable:

• A900-PWR550-D — the DC input version, for sites with a DC plant, which is the normal arrangement in telecom and utility cabinets.
• A900-PWR550-A — the AC input version, for sites fed from mains. It is priced higher than the DC unit.

On redundancy: a router chassis normally accepts two power supplies so that one feed can fail without dropping traffic. Ordering one supply because "it works in the lab" is the most common way a redundant design arrives non-redundant, and the fix afterwards is an urgent spare part rather than a planned purchase.

5. Do not mistake the small line items for equipment

Several items on this page are in the tens of dollars, and they are not modules or routers: blank filler panels (A900-HAS-BLANK, A900-PWR-BLANK, A903-RSPA-BLANK) close the unused slots so that airflow and thermal rating are maintained, a console kit (A900-CONS-KIT-U) provides the management cabling, and a cable guide (A903-CABLE-GUIDE) manages the fibre dress. They matter mechanically — an empty slot with no blank panel changes the chassis airflow — but they should be recognised as accessories when reading a quotation.

ASR 900 Compact Routers (A901 and ASR 920)

These are self-contained routers with no separate chassis, processor or module to order. They suit a small aggregation point, a cell site or a customer premises where a full chassis is more than the site needs.

Note the FT models: they add TDM (circuit-switched) interfaces alongside Ethernet, which matters when the site still terminates legacy leased lines rather than pure packet services. That capability is what accounts for their higher price over the equivalent plain-Ethernet model.

ASR 903 Chassis and Processors

Note that the chassis price is the smallest number in this table. The chassis alone is not a working router — it needs a processor and at least one interface module, which is why the usable cost of an ASR 903 is several times the chassis line item.

ASR 900 Interface Modules (IMA)

The 10G uplink module is the one item in this table that is about the router's own uplink rather than the customer-facing side — include it where the aggregation point is fed by a 10-Gigabit core and would otherwise be the bottleneck in its own design.

ASR 900 Power Supplies and Accessories

Prices are our current selling prices in US dollars, excluding shipping. Click a model number for the full specification table and availability.

Frequently Asked Questions

Is the ASR 903 chassis a complete router?

No. The ASR-903 line item on this page is the chassis, and it requires a route switch processor, at least one interface module, a power supply and a fan tray before it will carry traffic. When pricing a deployment, add those items to the chassis — the chassis is deliberately the smallest number in the table.

What is the difference between the A903-RSP1A-55 and the A903-RSP1B-55?

Forwarding scale. They are the standard-scale and large-scale route switch processors for the same chassis. The -55 is the licence tier in Cisco's router naming, so the two parts differ in the capacity and feature tier they carry rather than in the ports they present. Choose against the customer and link count the site will actually carry.

Which interface module should I choose?

Whichever one terminates the circuits you are actually connecting. The copper modules take conventional Ethernet links, the SFP-based modules take fibre, and the channelised optical module terminates higher-rate optical links and presents them as lower-rate services. Identify the interface type from the circuit inventory first — the physical interface cannot be changed on the module afterwards.

Do I need the AC or the DC power supply?

It depends on what feeds the rack. DC sites — telecom cabinets, utility installations, most outdoor cabinets — take A900-PWR550-D; mains-fed equipment rooms take A900-PWR550-A. They are not interchangeable, and the two are priced differently, so confirm the supply type before ordering.

Why are several items on this page only a few tens of dollars?

Those are accessories, not equipment: blank filler panels, a console cable kit, a cable guide and rack-mount brackets. Blank panels in particular matter mechanically — an unoccupied slot left open changes the chassis airflow and its thermal rating — but they should not be confused with modules when reading a bill of materials.

What makes the FT models more expensive than the plain models?

The FT suffix adds TDM interfaces alongside the Ethernet ports. On networks that still terminate circuit-switched leased lines, that capability is the whole reason to buy the model, and it is what the price difference buys.

Do you supply the SFP optics for the fibre modules?

Yes. The SFP transceivers and the matching single-mode or multimode patch cords are stocked separately from the modules. Give us the module part number and the link distances and we will quote the complete optical link.

Can these components be used to expand an existing ASR 900 installation?

Yes, and that is a common use for this page. Interface modules, power supplies, fan trays and mounting kits are the parts an installed chassis needs as it is expanded or as spares are stocked. Tell us the existing chassis and we will confirm compatibility of the specific module or supply you need.