The HA-APN is composed of two parts as follows:
The HA-APN Network Identifier; this defines to which external network the HA is connected.
The HA-APN Operator Identifier; this defines in which PLMN the HA serving the HA-APN is located.
The HA-APN Operator Identifier is placed after the HA-APN Network Identifier. The HA-APN consisting of both the Network Identifier and Operator Identifier corresponds to a FQDN of a HA; the HA-APN has, after encoding as defined in the paragraph below, a maximum length of 100 octets.
The encoding of the HA-APN shall follow the Name Syntax defined in RFC 2181
, RFC 1035
and RFC 1123
. The HA-APN consists of one or more labels. Each label is coded as a one octet length field followed by that number of octets coded as 8 bit ASCII characters. Following RFC 1035
the labels shall consist only of the alphabetic characters (A-Z and a-z), digits (0-9) and the hyphen (-). Following RFC 1123
, the label shall begin and end with either an alphabetic character or a digit. The case of alphabetic characters is not significant. The HA-APN is not terminated by a length byte of zero.
For the purpose of presentation, a HA-APN is usually displayed as a string in which the labels are separated by dots (e.g. "Label1.Label2.Label3").
The HA-APN Network Identifier follows the format defined for APNs in clause 9.1.1
. In addition to what has been defined in clause 9.1.1
the HA-APN Network Identifier shall not contain "ha-apn." or "w-apn." and not end in ".3gppnetwork.org".
A HA-APN Network Identifier may be used to access a service associated with a HA. This may be achieved by defining:
a HA-APN which corresponds to a FQDN of a HA, and which is locally interpreted by the HA as a request for a specific service, or
a HA-APN Network Identifier consisting of 3 or more labels and starting with a Reserved Service Label, or a HA-APN Network Identifier consisting of a Reserved Service Label alone, which indicates a HA by the nature of the requested service. Reserved Service Labels and the corresponding services they stand for shall be agreed between operators who have roaming agreements.
As an example, the HA-APN for MCC 345 and MNC 12 is coded in the DNS as:
where "internet" is the HA-APN Network Identifier and "mnc012.mcc345.pub.3gppnetwork.org " is the HA-APN Operator Identifier.