Section: 23.2 OAM System Realm/Domain
Content: The OAM System Realm/Domain shall be in the form of an Internet domain name, e.g. operator.com, as specified in IETF RFC 1035 [19] and IETF RFC 1123 [20]. The OAM System Realm/Domain consists of one or more labels. Each label shall consist of the alphabetic characters (A-Z and a-z), digits (0-9) and the hyphen (-) in accordance with IETF RFC 1035 [19]. Each label shall begin and end with either an alphabetic character or a digit in accordance with IETF RFC 1123 [20]. The case of alphabetic characters is not significant. The OAM System Realm/Domain shall be in the form of "oam.mnc<MNC>.mcc<MCC>.3gppnetwork.org", where "<MNC>" and "<MCC>" fields correspond to the MNC and MCC of the operator's PLMN. Both the "<MNC>" and "<MCC>" fields are 3 digits long. If the MNC of the PLMN is 2 digits, then a zero shall be added at the beginning. For example, the OAM System Realm/Domain of an IMSI shall be derived as described in the following steps: 1. take the first 5 or 6 digits, depending on whether a 2 or 3 digit MNC is used (see 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [27]) and separate them into MCC and MNC; if the MNC is 2 digits then a zero shall be added at the beginning; 2. use the MCC and MNC derived in step 1 to create the "mnc<MNC>.mcc<MCC>.3gppnetwork.org" domain name; 3. add the label "oam" to the beginning of the domain name. An example of an OAM System Realm/Domain is: IMSI in use: 234150999999999; Where: MCC = 234; MNC = 15; MSIN = 0999999999; Which gives the OAM System Realm/Domain name: oam.mnc015.mcc234.3gppnetwork.org. NOTE: If it is not possible for a Relay Node to identify whether a 2 or 3 digit MNC is used (e.g. USIM is inserted and the length of MNC in the IMSI is not available in the "Administrative data" data file), it is implementation dependent how the Relay Node determines the length of the MNC (2 or 3 digits).