4.2.103 EF_ePDGId (Home ePDG Identifier)

31.1023GPPCharacteristics of the Universal Subscriber Identity Module (USIM) applicationRelease 17TS

If service n°106 and service n°107 are "available", this file shall be present.

This EF contains zero or more Home Evolved Packet Data Gateway (ePDG) Identifier data objects as defined in the "Selection of the ePDG" UE procedure of 3GPP TS 24.302 [79].

Identifier: ‘6FF3’		Structure: transparent			Optional
File size: >X bytes			Update activity: low
Access Conditions: READ PIN UPDATE ADM DEACTIVATE ADM ACTIVATE ADM
Bytes	Description			M/O		Length
1 to X	Home ePDG identifier TLV data object			O		X bytes
X+1 to Y	Home ePDG identifier TLV data object			O		Y-X bytes
…

Home ePDG Identifier TLV data object

Contents:

– Address of Evolved Packet Data Gateway, in the format of a FQDN, an IPv4 address, or an IPv6 address.

Coding:

– The tag value of this Home ePDG Identifier TLV data object shall be ’80’. The format of the data object is as follows:

Field	Length (bytes)
Tag	1
Length	1
Address Type	1
Home ePDG Address	Address Length

Address Type: Type of the ePDG address.

– This field shall be set to the type of the ePDG address according to the following:

Value	Address Type
’00’	FQDN
’01’	IPv4
’02’	IPv6
All other values are reserved

ePDG Address: Address of the Evolved Packet Data Gateway

Contents:

– This field shall be set to the address of the ePDG.

Coding:

– When the Address Type is set to ’00’, the corresponding ePDG FQDN Address shall be encoded to an octet string according to UTF-8 encoding rules as specified in IETF RFC 3629 [48].

– When the Address Type is set to ’01’, the corresponding ePDG IPv4 Address is in octet 5 to octet 8 of the Home ePDG Identifier TLV data object. Bit 8 of octet 5 represents the most significant bit of the IP address and bit 1 of octet 8 the least significant bit.

– When the Address Type is set to ’02’, the corresponding ePDG IPv6 Address is in octet 5 to octet 20 of the Home ePDG Identifier TLV data object. Bit 8 of octet 5 represents the most significant bit of the IP address and bit 1 of octet 20 the least significant bit.

Unused bytes shall be set to ‘FF’.