What's New in This Guide

This section lists the documentation updates for release 25.2.2xx.

Release 25.2.201- G40404-03, August 2026

  1. NSSF Supported Features
    • Support for User-Agent Header
      • Expanded the notification conditions that cause NSSF to send requests to AMF.
      • Added details about registration and heartbeat requests sent to NRF.
      • Added the User-Agent Header generation flow through the Egress Gateway.
      • Clarified the use of nfType, nfInstanceId, nfFqdn, addFqdnToHeader, and overwriteHeader.
      • Clarified that an existing User-Agent Header is overwritten or forwarded unchanged according to overwriteHeader.
    • Deleting Subscription on 404 SUBSCRIPITON_NOT_FOUND Response from AMF
      • Revised the feature description to explain that NSSF avoids unnecessary retries by deleting the subscription immediately after receiving 404 SUBSCRIPTION_NOT_FOUND.
      • Corrected the referenced metric from ocnssf_nssaiavailability_notification_db_error to ocnssf_nssaiavailability_notification_db_error_total.
    • Support for Compression Using Accept-Encoding or Content-Encoding gzip
      • Added OPTIONS to the allowed methods returned with a 415 Unsupported Media Type response.
    • Dynamic Log Level Update
      • Changed commonCfgClient.enabled from a user-configurable enablement parameter to an engineering parameter that is enabled by default and must not be modified.
  2. Configuring NSSF using CNC Console
  3. NSSF Metrics, KPIs, and Alerts
    • Dimensions
      • Added profileType, with the values complete, partial, or null.
      • Added nssf instance ID to identify the NSSF instance associated with a notification.
      • Added event, supporting NF_REGISTERED, NF_DEREGISTERED, and NF_PROFILE_CHANGED.
    • NSSF Success Metrics
      • Added ocnssf_nsselection_requests_duration_seconds_sum.
      • Added ocnssf_nsselection_requests_duration_seconds_count.
      • Added ocnssf_nsselection_requests_duration_seconds_max.
      • Added the exception dimension to all three NSSelection duration metrics.
    • Egress Gateway Metrics
      • Added oc_egressgateway_http_requests_total.
      • Added oc_egressgateway_http_responses_total.
    • Ingress Gateway Metrics
      • Added oc_ingressgateway_http_requests_total.
      • Added oc_ingressgateway_http_responses_total.
    • NSSF Common metrics
      • Removed the generic http_requests_total and http_responses_total metrics; gateway-specific request and response metrics now provide this information.
      • Removed the http_request_bytes and http_response_bytes histogram metrics.
    • NSSelection KPIs
      • Updated the 4xx and 5xx KPI expressions to use the Route_path dimension instead of Uri.
      • Corrected the status-code regular expressions by removing the trailing space.
    • NSAvailability KPIs
      • Corrected the route expression from nnssf-nsavailability to nnssf-nssaiavailability.
      • Removed the incorrect Method="GET" restriction from the 4xx and 5xx response KPIs.
      • Corrected the 5xx KPI status expression from 4.* to 5.*.
    • Ingress Gateway KPIs
      • Replaced oc_ingressgateway_http_requests with sum(rate(oc_ingressgateway_http_requests_total[5m])) for calculating the NSSF ingress-request rate.
    • OcnssfNrfInstancesInDownStateMajor
      • Replaced the hard-coded alert condition of fewer than three healthy NRF instances with a condition based on the number of NRFs actually configured.

Release 25.2.200- G40404-02, April 2026

Release 25.2.200- G40404-01, February 2026

  • Feature Updates:
    • New Features:
      • NRF Client Retry and Health Check: The NRF Client Health Check continuously and automatically assesses the health of NRF instances, ensuring high service availability and seamless failover, especially in georedundant environments. It features configurable intervals, intelligent health status updates, and a retry mechanism to minimize service disruption and manage network failures.
        • No new metrics have been added for this feature. However, it uses the existing "nrfclient_nrf_operative_status" metric from the NSSF Common metrics section.
        • No new alerts have been added for this feature. However, it uses the following Application Level Alerts:
          • OcnssfAllNrfInstancesInDownStateCritical
          • OcnssfNrfInstancesInDownStateMajor
      • Support for TLSv1.3 on Internal API Communication: Improved security for inter-service communication, reinforced by new metrics to monitor TLS certificate statuses and address resolution failures.
        • Added the following metrics in the NSSF Metrics section:
          • oc_ingressgateway_ip_addresses_fetch_failure
          • oc_egressgateway_ip_addresses_fetch_failure
          • oc_certificatemanagement_tls_certificate_info
          • oc_certificatemanagement_tls_secret_status
          • oc_certificatemanagement_tls_certs_reload_failure
          • cgiu_jetty_ip_address_fetch_failure
      • Support for Dual Stack: Added comprehensive handling for both IPv4 and IPv6, with new monitoring metrics to track ingress and egress IP types and rejections.
        • Added the following metrics in the NSSF Metrics section:
          • oc_ingressgateway_incoming_ip_type
          • oc_ingressgateway_outgoing_ip_type
          • c_egressgateway_incoming_ip_type
          • oc_egressgateway_outgoing_ip_type
          • oc_egressgateway_dual stack_ip_rejected_total
    • Architectural Enhancements:
      • The NSSF’s core architecture has been redesigned to implement an in-memory, pod-level cache, reducing latency and dramatically boosting throughput. NsSelection throughput has increased from 10k to 80k TPS (an 8x improvement), with CPU consumption scaling from 60 to 120 cores (a 2x increase).
      • The architecture now supports large-volume messages in NsAvailability PUT operations, allowing all TAIs to be transmitted in a single message.
      • The NSSF schema and REST APIs have been overhauled to support in-memory caching. Corresponding REST API configuration options and details are now available directly from the CNC Console.
    • Deprecations and Removals (Driven by Architectural/Business Requirements)
      • Autopopulation of Configuration Using NRF Content: Removed due to the introduction of new Candidate AMF selection logic and redundancy in AMF set configuration with updated functional behavior.
      • Handover from EPS to 5G: Deprecated, as call transfer use cases are now handled through independent selection requests per updated customer requirements.
      • Optimized NSSAI Availability Data Encoding and TAI Range: Removed because TAI ranges are no longer viable, given non-incremental TAC assignments reported by customers.
      • Protection from Distributed Denial-of-Service (DDoS) Attack through Rate Limiting and Ingress Gateway Pod Protection: Both features are now obsolete with the introduction of pod-level rate limiting and updated protection mechanisms in the gateway’s latest releases.
      • Time of the Day Based Network Slice Instance Selection: Deprecated from this release.
      • IPv6 Support: Removed as a standalone feature and superseded by the "Support for Dual Stack feature.
      • Ingress Gateway Pod Protection: Removed as it is now considered obsolete due to the introduction of pod-level rate limiting in newer gateway releases.
      • Deprecated metrics and alerts have been cleaned up for a more focused monitoring and troubleshooting experience.
      • Details of several existing alerts and metrics have been updated and outdated alerts and metrics have been removed.
  • General Updates:
    • Updated release number to 25.2.200 throughout the document.
    • Added a feature description section for Support for cnDBTier APIs in CNC Console. The corresponding UI details were also updated for it in the Configuring NSSF using CNC Console section.
    • Configuring NSSF using CNC Console: New and redesigned UIs simplify CNC-configured NSSF options, system settings, and profile management, while outdated UIs have been removed to streamline user interaction.
    • Updated Table 4-20 in Support for Compression Using Accept-Encoding or Content-Encoding gzip feature section to remove the unsupported POST method from the response.
    • Added new error scenarios for Subscription with HTTP Patch (Option ADD in the Subscription Modification Feature section.
    • Added the following new NSSF Metrics:
      • ocnssf_indirect_communication_request_rx_total
      • ocnssf_indirect_communication_response_tx_success_total
      • ocnssf_indirect_communication_response_tx_failure_total
      • ocnssf_subscription_request_rx
      • ocnssf_subscription_response_tx_success_total
      • ocnssf_subscription_response_tx_failure_total
      • ocnssf_nssaiavailability_error_tx_total
      • ocnssf_nssaiavailability_options_tx_status_unsupportedmediatype_total
      • ocnssf_nsavailability_unsupported_plmn_total
      • ocnssf_state_data_write_error_total
      • stale_records_computation_DQD_amf_tai_slice_availability_data_seconds_count
      • stale_records_computation_JL_amf_tai_slice_availability_data_seconds_count
      • total_stale_records_APD_amf_tai_slice_availability_data_seconds_count
      • count_amf_tai_slice_availability_data_stale_records_deleted_total
      • stale_records_computation_DQD_nssai_subscriptions_seconds_count
      • stale_records_computation_JL_nssai_subscriptions_seconds_count
      • total_stale_records_APD_nssai_subscriptions_seconds_count
      • count_nssai_subscriptions_stale_records_deleted_total