Behavior Change

The SMF generates the IPv6 interface ID without International Mobile Subscriber Identity (IMSI) or Extended Unique Identifier (EUI).

Previous Behavior: The SMF generated the IPv6 interface ID in EUI-64 format based on configured or default virtual-mac under DNN. The interface ID is common for all subscribers under DNN. This operation resulted in apps like Google Duo to reject connections due to security policy.

New Behavior: The SMF generates unique 64-bit interface ID which is non-EUI-64 format by using SBI VIP address and CommonId of the subscriber.

That is, IPv6 interface ID = VIP-IP (4 bytes) + CommonId (4 bytes)

By default, virtual-mac CLI command is now disabled under DNN configuration.

Interface ID for Different Messages

Call Model

PDU Session Establishment Accept

Create Session Response

5G

N11-SBI-VIP+CommonID

Not Applicable

4G

Not Applicable

GTP-VIP+CommonID

WiFi

Not Applicable

GTP-VIP+CommonID

5G->4G

Not Applicable

Not Applicable (N26 HO - there are NAS contents during handover)

4G->5G

Not Applicable (N26 HO - there are NAS contents during handover)

Not Applicable

4G->WiFi

Not Applicable

GTP-VIP+CommonID (Same as 4G)

WiFi->4G

Not Applicable

GTP-VIP+CommonID (Same as 4G)

5G->WiFi

Not Applicable

N11-SBI-VIP+CommonID (Same as 5G)

WiFi->5G

GTP-VIP+CommonID (Same as WiFi)

Not Applicable