1-7
Cisco ASR 1000 Series Aggregation Services Routers Software Configuration Guide
OL-16506-10
Chapter 1 Software Packaging and Architecture
Processes Overview
IOS as a Process
In almost all previous Cisco router platforms, an overwhelming majority of the internal software
processes are run using Cisco IOS memory.
The Cisco ASR 1000 Series Routers introduce a distributed software architecture that moves many
operating system responsibilities out of the IOS process. In this architecture, IOS, which previously was
responsible for almost all of the internal software processes, now runs as one of many Linux processes
while allowing other Linux processes to share responsibility for running the router.
This architecture allows for better allocation of memory so the router can run more efficiently.
Furthermore, the Cisco ASR 1000 Series Routers has a command-line interface in diagnostic mode that
can be accessed in certain scenarios even if the IOS process fails. See the
“Understanding the Diagnostic
Mode” section on page 2-7
for information on diagnostic mode.
Forwarding Manager
Manages the downloading of
configuration to each of the
ESPs and the communication
of forwarding plane
information, such as statistics,
to the IOS process.
RP (one per software
redundancy instance per
RP). Maximum of two
instances per RP.
ESP (one per ESP)
RPControl
ESPBase
Pluggable Services
The integration point between
platform policy application,
such as authentication and the
IOS process.
RP (one per software
redundancy instance per
RP). Maximum of two
instances per RP.
RPControl
Shell Manager
Provides all user interface
features and handling related
to features in the nonIOS
image of the consolidated
package, which are also the
features available in diagnostic
mode when the IOS process
fails.
RP (one instance per
RP)
RPControl
SPA driver process
Provides an isolated process
driver for a specific SPA.
SPA (one instance per
SPA per SIP)
SIPSPA
CPP driver process
Manages the CPP hardware
forwarding engine on the ESP.
ESP (one instance per
ESP)
ESPBase
CPP HA process
Manages HA state for the CPP
hardware forwarding engine.
ESP (one instance per
ESP)
ESPBase
CPP SP process
Performs high-latency tasks
for the CPP-facing
functionality in the ESP
instance of the Forwarding
Manager process.
ESP (one instance per
ESP)
ESPBase
Table 1-2
Individual Processes (continued)
Process
Purpose
Affected FRUs
SubPackage
Mapping
