SMF

3GPP LI Support

The 3GPP LI support is introduced to adhere to the 3GPP standards for lawful interception.

Event Failure Logs for vSMF interface

With this feature, the consistent event failure logs are enhanced to support the Create, Insert, Release, and Update procedures for the vSMF interface.

IPv6 Prefix Delegation from Local Pool

The SMF supports IPv6 Prefix Delegation, allowing User Equipment (UE) and Customer Premises Equipment (CPE) to request additional IPv6 prefixes for configuring routers or cellular gateway devices.

The delegated prefix length range allowed is from 48 to 62.

This IPv6 prefix delegation is especially beneficial for service providers as it helps manage subscriber networks more effectively by assigning a prefix to CPE devices acting as routers between the subscriber's internal network and the core network

Command introduced:

ipv6-prefix-delegation prefix length prefix_length dnn prefix-delegation vdnn in DNN Profile Configuration mode

Default Setting: Disabled – Configuration Required to Enable

Rolling Upgrade Optimization for Protocol PFCP Pods

For the protocol (PFCP) pods, Converged Core Gateway introduces a session-level response messages cache at the service pod for handling the retransmitted requests. This optimization helps in reduced session and Call Events Per Second (CEPS) loss during the upgrade procedure.

Support for UE IP Address Hold and Reuse

This feature allows SMF to allocate the same IP address and session ID to a user session if the user reattaches within a configurable session hold timer after session release.

This feature improves the user experience and reduces the IP address exhaustion in scenarios where users frequently attach and detach.

Command introduced:

session-hold duration in Converged Core profile and DNN profile configurations

IoT

Support Seven Million Sessions on UCS 220 M7 Platform

This feature involves optimizing the SMF infrastructure to support up to seven million IoT call sessions on the UCS 220 M7 platform. The optimizations include improvements in radius-ep and GTPC-ep components and communication towards CDL component.

This optimization improves the reliability and scalability of the system, thereby ensuring efficient handling of large-scale IoT deployments.

CLI Console Changes:

Releases prior to 2024.04.0, the help string for detect-dead-server consecutive-failures displayed 10 as the default value.

In release 2024.04.0 and later, the help string for detect-dead-server consecutive-failures has been updated to reflect that the default value is disabled.

Commands introduced:

• enable-async { false | true } in the RADIUS endpoint configuration mode to enable asynchronous communication from RADIUS endpoint for RADIUS authentication, accounting, and CoA request messages. The default value is false.

• overload-control msg-type create-session-request in S5 interface configuration mode to apply rate limiting for Create Session Request messages.

SMF

Change in Log Level for MemoryCache

Previous Behavior: CDL pods and other app infrastructure pods displayed warning logs for ETCD operations, such as Update, Get, and Delete.

New Behavior: The log level for ETCD operations changed from warning to debug level, as these logs are intended for debugging purposes.

Message Priority Negotiation for High Priority Messages

Previous Behavior: SMF was not considering the message priority of the incoming messages that are coming over N4, GTPC, and SBA interfaces. SMF used to send the message priority in outgoing messages.

SMF Handling of SmContextStatusNotify for WiFi (N3IWF) to NR Handover

Previous Behavior: By default, SMF sends the SmContextStatusNotify to AMF without checking the "3GPP 23.502" compliance version for "WiFi (N3IWF) to NR" and "NR to WiFi" handover in intra PLMN scenarios.

IoT

Destination-Host and Destination-Realm AVP Support for Dynamic Route

Previous Behavior:

• For CCR-U/T, if the route list of bounded peer does not have active dynamic route, it continues to refer the route list of same peer for sending out the request.

• Whenever the peer switch happens for an existing session, the destination-host is set as per the switched peer

• Whenever the peer switch happens for an existing session, the destination-realm is set as per the switched peer.

• If the route list has only dynamic routes based on host/realm details, the static or patchcache route of bounded peer is not added to list of route.

New Behavior:

• For CCR-U/T, if the route list of primary does not have any dynamic route then secondary is considered for sending the message.

• When peer switch occurs for an existing session, the Destination-Host value is set as empty.

• When peer switch occurs for an existing session, Destination-Realm AVP is set as the origin-realm received in the previous CCA-I/U.

• If the route list of host has only dynamic routes, static or patchcache route of peer associated with route is added to the list.

Destination-Host Handling in Realm-Based Routes

Previous Behavior: When routing based on realms, SMF used the destination-host value of the selected host instead of the destination-host of the peer associated with the route.

New Behavior: When routing based on realms, SMF now uses the destination-host value specified in the peer configuration within the endpoint profile.

Expiry Time Handling for Dynamic Diameter Routes

Previous Behavior: In Diameter, once the dynamic route is created, the expiration time of dynamic route is not updated even if there is a message exchange using that dynamic route or the response is pointing to that dynamic route where the origin-host and origin-realm in response is different from the destination-host and destination-realm of request.

New Behavior: The expiration time of dynamic route is updated with the new expiration time if there is a message exchange using that dynamic route or if the response is pointing to that dynamic route where the origin-host and origin-realm in response is different from the destination-host and destination-realm of request.

Enhancement in EDR Configuration to Capture Transaction Priority

Previous Behavior: In SMF, the transaction priority of a message was not getting recorded in the EDR.

New Behavior: The EDR configuration is enhanced to capture the priority class of a message. Enabling this CLI displays an additional field in the EDR transaction files with an additional field containing one of the following two values:

• DefaultPriority

• HighPriority

Following is the new CLI:

[ no ] edr file transaction field priorityClass