IoT

Enable IPv6 Connectivity for SMF with Legacy Interfaces

SMF with legacy interfaces allows IPv6 address configuration to enable communication with the GTP, N4, Gx, and Gy interfaces. With this support, both IPv4 and IPv6 addresses can be used for peer connections. One peer connection can use either IPv4 or IPv6 address.

To enable IPv6 connectivity, SMF uses the existing endpoint { bgpspeaker | diameter | dns-proxy | geo | gtp | gtpprime | li | nodemgr | pfcp | protocol | radius | radius-dns | sbi | service | sgw-service } and dual-stack-transport { false | true } CLI commands.

Default Setting: Disabled – Configuration Required

SMF

Configuration-based Control of UDM Registration Messages

SMF allows the user to ignore the UDM registration messages during the PDU setup and Wi-Fi attach procedures.

With this controlled UDM registrations, the interactions between SMF and UDM over the N10 interface are minimized to handle the message overload and attach failures on the N10 interface.

This feature introduces the new CLI command skip-n10-registration rat-type [ NR | WIFI | ALL ] in the DNN profile.

Default Setting: Disabled – Configuration Required

Handling Traffic Flow for Dedicated UE Services

This feature allows specific UEs, like PTTs, to connect on the 5G RAT using specific TFTs. To enable this functionality, PCF sets the value of the PacketFilterUsage IE attribute to true in the dynamic PCC rule. This rule causes the SMF to only send the PCC Rule TFTs instead of the IP "Any-Any". This feature is only applicable for default flow.

Default Setting: Enabled - Always-on

SMF Instance-based UPF Selection

This feature allows you to customize SMF instances in the Subscriber Policy Configuration and to bind SMF instances to the colocated UPFs in the inter-site GR deployment model.

When the user selects operator policies, the SMF instances act as a filter and allow the SMF to select a specific DNN profile. The DNN selection helps in finding the closest and active Network functions (for example, UPFs) and ensures routing the user traffic only to the colocated UPFs. This implementation reduces the latency and improves user experience.

To implement this feature, the following keywords are added under the policy subscriber command:

instance-start-range

instance-stop-range

Default Setting: Disabled – Configuration required to enable

ARP Configuration for WPS Profile during SMF Upgrade

Previous Behavior: For any SMF upgrades prior to Release 2023.03, the ARP configuration in the WPS profile was retained as is.

New Behavior: For any SMF upgrades from Release 2023.03 to later releases, the ARP configuration gets removed. It is mandatory that you manually reconfigure the ARP parameter after the upgrade is complete.

GTP Echo Interval Configuration during SMF Upgrade

Previous Behavior: For any SMF upgrades prior to Release 2023.03, the GTP echo interval configuration in the S5 interface was retained as is.

New Behavior: For any SMF upgrades from Release 2023.03 to later releases, the GTP echo interval configuration gets removed. It is mandatory that you manually reconfigure the GTP echo interval for the S5 interface after the upgrade is complete.

Handling Multiple PCC Rules on N1 Interface and Sending Additional QER Per PDR on N4 Interface

Previous Behavior: On the N1 interface, if multiple PCC rules are associated to the default flow, the SMF sends multiple QoS Rules with DQR=1 and Packet filters for the PCC Rules. SMF sends or adds up the bitrates of all PCC rules associated to default flow in FBR IE.

On the N4 interface, for each of the PCC Rule associated to the default flow, SMF sends a CREATE_QER with the MBR set to the values of maxbrUl & maxbrDl sent by PCF in the QoS description for that PCC Rule. As QERs are unique for each PDR, SMF includes the gate status in the same QER as and when applicable based on the TC data associated to the PCC rule received from PCF.

New Behavior: As per the new behavior, on the N1 interface, SMF sends only one QoS Rule for default flow with DQR=1 and the Packet filter as “Any-Any” or specific TFT. SMF doesn’t send or add up the bitrates in the QoS description of the PCC Rules in FBR IE. The MBR value in UE is derived from session AMBR.

On the N4 interface, SMF doesn’t send a CREATE_QER for the PCC Rules QoS descriptions. The QER IDs in the PDRs for the PCC Rules are set to the Session Rules QER IDs. SMF includes an additional QER in the PDR of the PCC rule (along with the existing two QERs) specifically to display the gate status as enabled or disabled. The QER doesn’t contain any MBR information.

Handling Peer Delete Log during Reload

Previous Behavior: The application error log was captured even if the ETCD entry was deleted for a valid scenario.

Following is an example of error log where this log is marked as ERROR.

2024/03/08 06:22:38.700 smf-service-6 [ERROR] [MemoryCache.go:446] [infra.memory_cache.core] Reload cache, key C.GR.1.peergtpnodeinfo1.x.x.x.x deleted

New Behavior: The log level of this error log is changed to debug as this log is getting printed in the valid scenario.

Prioritized Processing of EDR Reporting for Subscribers

Previous Behavior: The edr reporting subscriber command when configured, didn’t allow the user to configure edr all subscribers command. It is expected that the user first disables the edr reporting with no edr reporting subscriber command and then configure edr all subscribers command.

New Behavior: The edr all subscribers command takes precedence over the edr reporting subscriber command when enabled. Through this prioritized processing, the user requires no additional configuration to remove the edr reporting subscriber.

SGW Peer Detection in Roaming Scenario

Previous Behavior: Roaming S-GW peers were showing as UNKNOWN_PEER in nodemgr logs and not tagged as "Roaming" in the SMF CCG software release 2023.03.m0.d8.0.i45 when seen with show peers all command.

New Behavior: Roaming S-GW peers are tagged as "Roaming" when seen with show peers all command.

UDM Registration Reattempt during 5G and Wi-Fi Handovers

Previous Behavior: If the UE registration failed during a 5G or Wi-Fi attach and if the UDM failure handling template (FHT) was configured as continue or ignore, then SMF didn't attempt registration in Wi-Fi to 5G and 5G to Wi-Fi handovers.

New Behavior: If the UE registration fails during a 5G or Wi-Fi attach and if the UDM FHT is configured as continue or ignore, then SMF reattempts the registration during Wi-Fi to 5G and 5G to Wi-Fi handovers.