The StarOS-based UPF node needs basic ECS rules configuration pushed from SMF. These default rules need to be provisioned in UPF dynamically even for dynamic PCC policy.

• The StarOS UPF expects SMF to send the configuration in a new custom message. This message is called SX_PRIME_PFD_MANAGEMENT_REQUEST. The custom message ID of this message is 0x2F.

• The response sent by UPF for this message is SX_PRIME_PFD_MANAGEMENT_RESPONSE with message ID 0x30.

The following snapshot shows the contents of this message:

[U-PLANE]PFCP Rx PDU, from 192.60.181.6:40259 to 192.60.181.2:8805 (81) 
SEID: NA, Message type: SX_MSG_PRIME_PFD_MANAGEMENT_REQUEST (0x2F) 
Sequence Number: 0x000001 (1) 
PFCP HEADER 
        Version number: 1 
        SEID flag: Not present 
        Message Length: 0x004D (77) 
INFORMATION ELEMENTS 
        CONFIG ACTION: 
            Type: 202  Length: 1 
            Value: ADD 
            Hex: 00CA 0001 01 
        CORRELATION ID: 
            Type: 203  Length: 2 
            Value: 4 
            Hex: 00CB 0002 0004 
        SUB PART NUMBER: 
            Type: 204  Length: 1 
            Value: 245 
            Hex: 00CC 0001 F5 
        CONTENT TLV: 
            Type: 206  Length: 53 
            Value: 
                Content Type: ACS_LEVEL_INFO 
                Content Length: 50 
            Hex: 00CE 0035 0B00 325C 00F1 015F 5F64 657F 
                 6661 756C 745F 5F10 0113 2C01 0111 C801 
                 132C 0101 132C 0101 532C 0101 0155 01FF 
                 01FF 0101 1001 032C 01 
Tuesday August 21 2018 
<<<<OUTBOUND  09:43:39:380 Eventid:221302(3) 
[U-PLANE]PFCP Tx PDU, from 192.60.181.2:8805 to 192.60.181.6:40259 (19) 
SEID: NA, Message type: SX_MSG_PRIME_PFD_MANAGEMENT_RESPONSE (0x30) 
Sequence Number: 0x000001 (1) 
PFCP HEADER 
        Version number: 1 
        SEID flag: Not present 
        Message Length: 0x000F (15) 
INFORMATION ELEMENTS 
        CAUSE: 
            Type: 19  Length: 1 
            Value: 
                Cause: PFCP_CAUSE_REQUEST_ACCEPTED (0x01) 
            Hex: 0013 0001 01 
        CORRELATION ID: 
            Type: 203  Length: 2 
            Value: 4 
            Hex: 00CB 0002 0004 

The StarOS UPF expects SMF to send the configured IP pool range for assigning the IP address to UE during PDU Session Creation. The UPF uses this information to install static routes for the entire range of IP addresses and advertises the same. The IP pool range information consists of:

• Start and End IP address of the pool range.

• VPN context ID in which the pool will be dynamically configured in UPF.

• SMF does not have any VPN ID supported in this release. It sends a configured value that also needs to be configured on UPF.

• IP pool chunk ID.

  SMF currently does not break the pool into smaller chunks and hence, it always sends 1 as the chunk ID.

• The IP pool information is sent to UPF in an N4 Association Update Request message after the N4 Association Setup Request/Response has been successfully exchanged with UPF and also after the SX Prime PFD Management Request/Response has been exchanged. The Content TLV IE (IE type 206) is used to send this pool information in the N4 Association Update Request.

As per 3GPP specifications, the NodeID attribute uniquely identifies an SMF to a UPF. This IE is a mandatory attribute in the N4 Session Establishment Request/Response message. The StarOS UPF currently does not support this IE in any of the Session Management related messages. As a customization, the SMF does not send this IE and does not expect this IE in the response messages.

As per 3GPP specifications, the FAR ID attribute has an ID type 108. The StarOS UPF assumes this IE type as 200. As a customization, the SMF sets 200 as the FAR ID IE type.

As per 3GPP specifications, the PDR sent to UPF may have a list of QFIs associated to all the QERs. The StarOS UPF currently supports only one QFI. As a customization, the SMF includes only one QFI.