Cisco XR 12406 - Manual (Page 24)

Chapter 1 Cisco XR 12406 Router Overview
Physical and Functional Description
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Cisco XR 12406 Router Installation Guide
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The Cisco PRP-2 and PRP-3 delivers all these functions with enhanced
performance and capabilities. It also delivers the following feature enhancements
(depending on the software version running):
• Gigabit Ethernet management port
• Hard-drive support (optional part)
• BITS input ports
• 1 GB compact image Flash memory support (optional part)
• Memory scalability up to 4 GB with PRP-2 and up to 8 GB with PRP-3.
The PRP-2 and PRP-3 communicates with the line cards either through the switch
fabric or through the MBus. The switch fabric connection is the main data path
for routing table distribution as well as for packets that are sent between the line
cards and the PRP. The MBus connection allows the PRP-2 and PRP-3 to
download a system bootstrap image, collect or load diagnostic information, and
perform general, internal system maintenance operations.
The PRP-2 can be designated as either the Designated System Controller (DSC)
or the Secure Domain router (SDR).
The Designated System Controller (DSC) performs the following functions:
• Implements control plane operations for the chassis
• Monitors temperature and voltage
• Monitors line cards
• On boot up, the first card to become active is designated as the DSC.
The Secure Domain Router (SDR) controls domain security features independent
of any other SDRs on the network.
In addition to the functionality listed for the PRP-2, PRP-3 provides the following
specific functions:
• Reduced boot time.
• Increased overall scalability.
• Improved memory access rates and scale.
• Improved CPU performance through dual 1.3-GHz PPC processor cores.
• Improved packet processing using hardware-based acceleration.
• 10-G bandwidth backplane connectivity.