Telemetry

Enhancements to Hardware Timestamp

Telemetry messages carry a timestamp per interface to indicate the time when data is collected from the hardware. With this feature, the support for hardware timestamp is extended to MPLS Traffic Engineering (MPLS TE) counters, Segment Routing for Traffic Engineering (SR-TE) interface counters, protocol statistics, and bundle protocol counters.

The interface counters in the following paths are enhanced for hardware timestamp:

• Cisco-IOS-XR-infra-statsd-oper:infra-

  statistics/interfaces/interface/cache

  /generic-counters

• Cisco-IOS-XR-infra-statsd-oper:infra-

  statistics/interfaces/interface/latest

  /generic-counters

• openconfig-network-instance:network-

  instances/network-instance/mpls/lsps/

  constrained-path/tunnels

• openconfig-interfaces:interfaces/interface

Programmability

OpenConfig YANG Model:AFT

This feature extends support to additional lists and containers in the OpenConfig Abstract Forwarding Table (AFT) model. With this support, the NMS receives only essential interface characteristics, such as next-hop group, next hop, and RSVP-TE for an IP prefix. As a result, the forwarding process is simplified for the NMS.

You can access the OC data model from the Github repository.

OpenConfig YANG Model:SR

Support has been extended for the following components in the OpenConfig (OC) Segment-Routing (SR) YANG model:

• The aggregate-sid-counters container in the sr-mpls-top group to aggregate the prefix-SID counters across all interfaces of the router.

• The aggregate-sid-counter list is supported along with the mpls-label key to aggregate counters across all the interfaces of the router corresponding to traffic forwarded with a particular prefix-SID.

You can access the OC data model from the Github repository.

OpenConfig YANG Model:SR-TE Policies

The OpenConfig (OC) Segment Routing-Traffic Engineering (SR-TE) YANG data model provides data definitions for SR-TE policy configuration and associated signaling and traffic engineering protocols. This release extends support for the following data model to stream telemetry data:

openconfig-srte-policy

You can access the OC data model from the Github repository.

Telemetry Accuracy Enhancements

In this release, the timestamp option is enabled for interface counters. This helps you retrieve an accurate set of statistics related to the operational state of the router in terms of label, packets-forwarded, and octets-forwarded for an interface.

The timestamp option is also enabled in the OC-AFT YANG model. The model facilitates the NMS to receive only essential interface characteristics, such as the next-hop group, next hop, and RSVP-TE for an IP prefix along with the timestamp. By using timestamped packets, the NMS is able to calculate the rate at which data is transmitted accurately.

See hardware timestamping for more information.

Segment Routing

IPv6 Autoroute Include Support for an SR-TE Policy with an IPv4 Endpoint

On the headend router, you can steer incoming IPv6 traffic into an SR-TE policy with an IPv4 endpoint. Prior to this, the support was available only for incoming IPv4 traffic.

New command:

BGP Best Path Computation using SR Policy Paths

BGP best-path selection is modified for a prefix when at least one of its paths resolves over the next hop using SR policies (SR policy in “up” state). Under this condition, paths not steered over an SR policy (those using native next-hop resolution) are considered ineligible during best-path selection.

You can thus control the best path selection in order to steer traffic, preferably or exclusively, over SR policies with the desired SLA.

This feature introduces the bgp bestpath sr-policy {force | prefer} command.

Modular QoS

Classifying Packets Based on MPLS Experimental Bits in MPLS Over GRE

For MPLS over GRE scenarios that tunnel MPLS traffic over non-MPLS networks, you can now perform QoS classification for specific traffic or applications based on MPLS EXP bit field values in the MPLS header.

In earlier releases, you could perform QoS classification only in the outer GRE IP header using DiffServ Code Point (DSCP) or IP precedence bits that helped you achieve the required line rate minus the granularity.

This feature introduces the hw-module profile qos gre-exp-classification-enable command.

Netflow

sFlow Enhancements

With this release, the following enhancements are available with sFlow:

• Discard codes 0, 1, 256, 257, and 258 are supported. This alerts the user about the packets dropped in the network.

• Syslog notifications for flow monitor buffer and ring buffer status.

System Monitoring

NOS Insights

The NOS Insights is an application that interacts with the NOS (Network Optimization Service) and collects data metrics through multiple methods such as NetConf, Telemetry, and Commands. It then analyzes the available datasets and information to detect a gray failure event in the device.