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Cisco ASR 903 Router Hardware Installation Guide
OL-25178-05
Chapter1 Cisco ASR 903 router Overview
CiscoASR 903 router Features
The air plenum is available from GAW (www.GawTechnology.net). To order an air plenum, contact the
Sales and Marketing support staff at GAW (see Table 6- 2).
RSP Modules
The Cisco ASR 903 router is designed to use up to two RSP modules to handle the data plane, network
timing, and control plane functionalities for the router. The RSP configuration allows you to use Cisco
IOS software to control chassis management, redundancy, external management, and system status
indications on the router.
The following sections describe the CiscoASR 903 router RSP:
•Supported RSP Features, page 1-10
•RSP Redundancy, page1-10
•Network Timing Interfaces, page1-10
•RSP Interfaces, page1-10
RSP features include:
•Loading software onto processor-based interface modules
•Redundant RSP management—The RSP manages detection of RSPs, exchange of health and status
information, role negotiation, function for detection, health and status exchange, role negotiation
•Packet processing
•Traffic management, including buffering, queuing, and scheduling, Ethernet MAC functions
•Network clocking functions including phase and time-of-day for BITS, 1 PPS, 10 MHz, and 1588
PTP clock references.
•Storage of software images, system configuration, OBFL, SysLog
•PTP packet processing including IEEE 1588-2008 for recovering network timing (frequency, phase,
and time) from upstream PTP clocks, for generating PTP frequency and phase references as inputs
to the SETS, and for distributing them to downstream PTP clocks
•External management interfaces (RS232 console, management ENET, USB console, USB storage)
and system status LED indicators

Supported RSPs

The Cisco ASR 903 router supports the following RSPs:
•A900-RSP1A-55—Provides 2 GB of SDRAM, 5 Mb of TCAM memory, 3-Mb buffer table,
576-Mb forwarding memory, and 1,536-Mb packet buffer memory.
•A900-RSP1B-55—Provides 4 GB of SDRAM, 20 Mb of TCAM memory, 144-Mb buffer table,
1152-Mb forwarding memory, and 1,536-Mb packet buffer memory.
Note The supported RSPs have different memory capacities, but they have the same interfaces and
functionality.