
to low-priority buffers. After the packets are classified into high priority and low priority, the packets are sent
to the ESP for further processing.
SIP-Based Classification
POS SPAs, channelized, and clear-channel SPAs support packet classification at SIP level. In SIP-based
classification, the SIP does the classification for SPAs and classifies the packet into high-priority and
low-priority.
Commands have been introduced in Release 3.1S to configure SIP based classification. To classify high-priority
packets such as IPv4, IPv6, or MPLS, in a SIP or SPA, the classification template is defined using the
ingress-class map index
command. The classification template-specific details are defined inside the template,
and the template is attached to an interface using the
plim qos class-map index
command.
Default Classification
Commands are used to configure the L3 packet classification criteria. If no L3 classification rule has been
configured, the SIP classifies the packet with the following L3 settings as high priority by default:
•
IPv4 DSCP-based
—
If no values are specified as high priority for IPv4 DSCP values, the system considers
packets with DSCP EF as high priority.
•
IPv4 precedence-based
—
If no values are specified as high priority for IPv4 precedence values, the
system considers packets with precedence 6-7 as high priority.
•
IPv6 TC-based
—
If no values are specified as high-priority for IPv6 DSCP values, the system considers
packets with DSCP EF as high priority.
•
MPLS EXP bits
—
If no values are specified as high-priority for MPLS EXP values, the system considers
packets with EXP values 6-7 as high priority.
High Availability and Online Insertion and Removal
•
CLI configured under an interface are retained after SPA online-insertion-and-removal (OIR). When
one type of SPA is replaced by another type of the SPA, the interface configuration is not retained.
However, if the earlier SPA type is reinserted, the configuration added on that SPA type is restored.
•
All the configurations are synced to the standby route processor (RP). Hence, the router configuration
is retained even after the RP switchover.
Configuring the Ingress Classification
The following section provides configuration details for classifying IPv4, IPv6, and MPLS packets for POS,
serial, channelized, and clear-channel SPAs.
Defining the L3 Classification Template
To classify high-priority packets such as IPv4, IPv6, or MPLS in either a SIP or SPA, the classification
template is defined using the
ingress-class map index
command. The classification rules are defined inside
the template, and the template is attached to an interface using the
plim qos input class-map index
-
id
command.
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS XE
Everest 16.5
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Classifying and Scheduling Packets for the ASR 1000 Series Aggregation Services Routers
Configuring the Ingress Classification