UCC 5G AMF Release Notes, Release 2026.02.0

First Customer Ship (FCS)

23-Apr-2026

End of Life (EoL)

23-Apr-2026

End of Software Maintenance (EoSM)

22-Oct-2027

End of Vulnerability and Security Support (EoVSS)

22-Oct-2027

Last Date of Support (LDoS)

31-Oct-2028

Ease of Setup

DNS-based discovery of MMEs

This feature enhances seamless interworking between 5G Core (5GC) and Evolved Packet Core (EPC) networks by automating the MME selection process. Instead of relying only on static peer MME configurations, the AMF can perform DNS queries (using NAPTR records) to dynamically discover suitable MMEs in supported scenarios. The feature is controlled by CLI configuration and supports both idle and connected mobility procedures.

Command introduced:

amf-services amf_service_name { peer-mme dns-discovery enabled }— Activates DNS-based dynamic discovery of peer MMEs for the specified AMF service.

Default Setting: Disabled – Configuration Required

Ease of Setup

DSCP marking for SBI interface

AMF applies DSCP marking to outgoing packets on the SBI interfaces, ensuring that traffic is handled appropriately.

Command introduced:

config { instance instance-id instance_id { endpoint sbi { dscp dscp_value } } }— Used to configure the DSCP value for SBI interface.

Default Setting: Disabled – Configuration Required

Ease of Setup

Local cause codes update for 5G attachment restrictions

Operators can now quickly redirect subscribers from 5G to 4G during network issues by rejecting 5G attachments with specific cause codes.

AMF supports configurable local NAS cause codes for rat-type and registration restrictions. Operators can enable and select from predefined cause codes using CLI, such as "5GS-services-not-allowed," "N1 mode not allowed," and "redirection to EPC required." This mechanism allows the system to reject subscriber attempts to attach to 5G, triggering redirection to 4G without impacting performance or backup processes.

Command introduced:

·       local-cause-code-map name cause_code_profile_name { rat-type-restriction cause-code5gmm { 5GS-services-not-allowed | N1-mode-not-allowed | redirection-to-epc-required } }— Used to configure the 5GMM cause codes for local cause-code mapping under the "amf-global call-control-policy" and "amf-service". The default value is "plmn-not-allowed".

·       local-cause-code-map name cause_code_profile_name { registration-restriction cause-code5gmm { N1-mode-not-allowed | redirection-to-epc-required } }— Used to configure the 5GMM cause codes for local cause-code mapping under the "amf-global call-control-policy" and "amf-service". The default value is "plmn-not-allowed".

Default Setting: Disabled – Configuration Required

Upgrade

AMF set deployment in different cluster

AMF Sets improve network reliability and session continuity by allowing multiple AMF instances to share user context and provide seamless service, even during failures. Multiple AMFs in an AMF Set share UE context using a Common Data Layer (CDL) for synchronization. If one AMF fails, another in the set quickly takes over, ensuring uninterrupted service. AMF Sets can span different Kubernetes clusters and regions, with unique identifiers for each set and region. The system supports context sharing and subscriber migration across AMFs, with secure data stored and synchronized in the CDL.

Command introduced:

amf-services amf_services_name { guamis { mcc mcc_value | mnc mnc_value | region-id region_id | set-id set_id | pointer pointer_value { amf-name amf_name | backup-amf-name backup_amf_name | offline-mode } } }  — Used to configure the amf-name and backup-amf-name for specific GUAMIs under AMF services.

 Default Setting: Disabled – Configuration Required

Enhanced subscriber information visibility and clearing in AMF

Previous Behavior: The AMF displayed subscriber information even after a subscriber was cleared, persisting until the tpurge timer expired. This made it difficult to distinguish between attached and terminated subscribers.

New Behavior: The AMF has updated subscriber visibility and clearing mechanisms to align with MME-like behavior:

·       Subscriber Visibility: The show subscriber supi <supi-val> command now only displays information if the subscriber is currently registered. To view GUTI information for subscribers that are not currently registered, use the new show subscriber guti <guti-val> command.

·       Subscriber Clearing: The clear subscriber command now supports immediate purging and local-only purging:

o   clear subscriber supi <supi-val> tpurge 0: Purges the subscriber information immediately.

o   clear subscriber supi <supi-val> local-purge true: Purges the subscriber locally without informing peer nodes.

·       New Cause Code: A new default cause code, implicitly-de-registered, has been added to the local-cause-code-map for clear-subscriber operations.

Support for static NF instance ID (UUID)

Previous Behavior: The AMF generated a dynamic UUID upon each redeployment, which was used for NRF registration. This resulted in the NF instance ID changing whenever the AMF was redeployed.

New Behavior: The AMF now supports the optional configuration of a static NF instance ID (UUIDv4). You can configure a fixed UUID using the uuid command within the amf-services configuration mode. To ensure the new value is correctly applied, a shut-start of the ops center is required after configuring the UUID.

Example:

amf-services am1

   uuid 12345678-1234-5678-1234-567812345678

   exit

UE radio capability match request timing

Previous Behavior: The AMF sent the UE Radio Capability Check Request to the gNB prior to the completion of the Initial Context Setup Response (ICSR).

New Behavior: The AMF now defers the UE Radio Capability Check Request until after the ICSR has been completed, ensuring that AS security is fully activated before the gNB attempts to retrieve UE capabilities.

CSCwt79481

Protocol pod crash after failover due to panic error for (*ASN1Writer).PutOctetString

CSCwt66864

AMF Pods Running as Root User Violates Least Privilege Principle

CSCwu05228

AMF is not marking NF status change notification response towards NRF with configured DSCP

Ultra Cloud Core SMI

2026.02.1.07

Ultra Cloud CDL

2.2.0

amf.2026.02.0.SPA.tgz

2026.02.0

cdl-2.2.0-amf-2026.02.0.SPA.tgz

2.2.0

NED package

ncs-6.4.8.2-amf-nc-1.1.2026.02.0

NSO

6.4.8.2

Microsoft Windows

Open a command line window and type the following command:

> certutil.exe -hashfile <filename.extension> SHA512

Apple MAC

Open a terminal window and type the following command:

$ shasum -a 512 <filename.extension>

Linux

Open a terminal window and type the following command:

$ sha512sum <filename.extension>

OR

$ shasum -a 512 <filename.extension>

<filename> is the name of the file. <extension> is the file type extension (for example, .zip or .tgz).

AMF documentation

Access and Mobility Management Function

SMI documentation

Subscriber Microservices Infrastructure

Service Request and Additional information

Cisco Support