Merge branch 'ue-to-ue-traffic' into packet-core-4.15

Author: b-branco

articles/private-5g-core/collect-required-information-for-a-site.md

@@ -72,7 +72,7 @@ Collect all the values in the following table to define the packet core instance
    |The data subnet default gateway. You identified this in [Allocate subnets and IP addresses](complete-private-mobile-network-prerequisites.md#allocate-subnets-and-ip-addresses) and it must match the value you used when deploying the AKS-HCI cluster.                               |**N6/SGi gateway**|
    | The network address of the subnet from which dynamic IP addresses must be allocated to user equipment (UEs), given in CIDR notation. You won't need this address if you don't want to support dynamic IP address allocation for this site. You identified this in [Allocate user equipment (UE) IP address pools](complete-private-mobile-network-prerequisites.md#allocate-user-equipment-ue-ip-address-pools). The following example shows the network address format. </br></br>`198.51.100.0/24` </br></br>Note that the UE subnets aren't related to the access subnet.    |**Dynamic UE IP pool prefixes**|
    | The network address of the subnet from which static IP addresses must be allocated to user equipment (UEs), given in CIDR notation. You won't need this address if you don't want to support static IP address allocation for this site. You identified this in [Allocate user equipment (UE) IP address pools](complete-private-mobile-network-prerequisites.md#allocate-user-equipment-ue-ip-address-pools). The following example shows the network address format. </br></br>`198.51.100.0/24` </br></br>Note that the UE subnets aren't related to the access subnet.    |**Static UE IP pool prefixes**|
-   |Whether Network Address and Port Translation (NAPT) should be enabled for this data network. NAPT allows you to translate a large pool of private IP addresses for UEs to a small number of public IP addresses. The translation is performed at the point where traffic enters the data network, maximizing the utility of a limited supply of public IP addresses.    |**NAPT**|
+   |Whether Network Address and Port Translation (NAPT) should be enabled for this data network. NAPT allows you to translate a large pool of private IP addresses for UEs to a small number of public IP addresses. The translation is performed at the point where traffic enters the data network, maximizing the utility of a limited supply of public IP addresses.</br></br>If you want to use [UE-to-UE traffic](private-5g-core-overview.md#ue-to-ue-traffic) in this data network, keep NAPT disabled.  |**NAPT**|
 
 ## Next steps
 

articles/private-5g-core/private-5g-core-overview.md

@@ -133,6 +133,12 @@ Azure Private 5G Core supports the following algorithms for ciphering and integr
 - 128-bit Snow3G
 - 128-bit Advanced Encryption System (AES) encryption
 
+### UE-to-UE traffic
+
+Azure Private 5G Core supports traffic flow from UE to UE through the user plane, allowing machine-to-machine (M2M) communication between 5G devices for a range of applications including robot control.
+
+An external router is responsible for hairpinning traffic from UE to UE over the N6 interface. This means that traffic leaving the UPF destined to a UE IP address will be routed back to the UPF’s N6 IP address.
+
 ### Index to RAT/Frequency Selection Priority (RFSP)
 
 The packet core instance can provide a RAN with an RFSP Index. The RAN can match the RFSP Index to its local configuration to apply specific radio resource management (RRM) policies, such as cell reselection or frequency layer redirection.