• Checking the authorization of data access is not supported. All the data requested by a subscriber is sent. • Subtree filters are not supported. If subtree filters are specified, the subscription is marked as invalid. • Defining multiple receivers within subscription parameters is not supported; only the first receiver destination is attempted. Other defined receivers are ignored. • On Cisco Catalyst 9800 Wireless Controllers, the value of tx-retries and excessive-retries fields in the /client-oper-data/traffic-stats/ XPath will always display zero. To view the total number of times a clients tries to resend a packet, use the data-retries field of the XPath.
gRPC-Specific Restrictions • Transport Layer Security-based (TLS-based) authentication between a device and a receiver is not supported. TLS-based authentication is supported in Cisco IOS XE Amsterdam 17.1.1 and later releases. yang-push-Specific Restrictions • Subscription quality of service (QoS) is not supported. gRPC Telemetry Configured Subscriptions Restrictions • Multiple subscriptions are dropped during normal operation. This issue was caused by a bug in the gRPC library that kept sending keepalive pings when keepalives were disabled. This issue was fixed through https://github.com/grpc/grpc/pull/22997 in the following Cisco IOS XE releases:
• Cisco IOS XE Cupertino 17.9.6 • Cisco IOS XE Dublin 17.12.2 • Cisco IOS XE 17.13.1 and later releases However, if you are using an Cisco IOS XE version without the fix, as a workaround, decrease the value of the GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS parameter on the receiver to below 5 minutes. For more information about this parameter, see https://github.com/grpc/grpc/blob/master/doc/keepalive.md . Some gRPC receivers may have a configuration option to decrease the value of the parameter. For example, telegraf has "inputs.cisco_telemetry_mdt.grpc_enforcement_policy.keepalive_minimum_time". See:
https://github.com/influxdata/telegraf/tree/master/plugins/inputs/cisco_telemetry_mdt#configuration . Information About Model-Driven Telemetry The following sections provide information about the various aspects of model-driven telemetry. Model-Driven Telemetry Overview Telemetry is an automated communications process by which measurements and other data are collected at remote or inaccessible points and transmitted to the receiving equipment for monitoring. Model-driven telemetry provides a mechanism to stream YANG-modeled data to a data collector. Model-Driven Telemetry Information About Model-Driven Telemetry Model-Driven Telemetry 5