The 903 is a 3RU device with six interface module slots and two route/switch processors slots. Two RSPs are available for the router: one supports 2GB of memory and the other 4GB.

Interface modules include a one-port 10G Ethernet XFP card, eight-port 10/100/1000Mbps Ethernet and Gigabit Ethernet SFP, four-port OC-3/STM-1 or one-port OC-12/STM-4, and 16-port T-1/E-1. The router also supports three different Cisco IOS software licenses: The Metro Services license offers advanced QoS, Carrier Ethernet Layer 2 features, synchronous Ethernet and Ethernet OAM capability; the Metro IP Services license offers all capabilities of the Metro Services license with the addition of Bidirectional Forwarding Detection, Layer 3 routing protocols, multi-VPN routing and Layer 3 Multicast and Forwarding Customer Edge capabilities; and the Metro Aggregation Services license includes all of the above, plus MPLS and Circuit Emulation.

The 903 also include four additional optional licenses -- two for enabling ATM and IEEE 1588-2008 Boundary Clock or Master Clock capabilities; and two to enable ports on the multi-rate OC-3 and OC-12 interface module.

The 9001 supports 120Gbps of throughput in a 2RU form factor. It has an integrated RSP and two modular bays that support 20-port Gigabit Ethernet, two- and four-port 10G Ethernet and future 40G Ethernet port adapters. The base chassis also has four integrated 10G Ethernet SFP+ ports.

The integrated RSP has 8GB of RAM and is capable of holding several million routes, Cisco says.