Section: 19.3.4 Fast Re-authentication NAI
Content: The Fast Re-authentication NAI shall take the form of a NAI as specified in clause 2.1 of IETF RFC 4282 [53]. If the 3GPP AAA server does not return a complete NAI, the Fast Re-authentication NAI shall consist of the username part of the fast re-authentication identity as returned from the 3GPP AAA server and the same realm as used in the permanent user identity. If the 3GPP AAA server returns a complete NAI as the re-authentication identity, then this NAI shall be used. The username part of the fast re-authentication identity shall be decorated as described in 19.3.3 if the Selected PLMN is different from the HPLMN. For EAP-AKA authentication, the username portion of the fast re-authentication identity shall be prepended with the single digit "4" as specified in clause 4.1.1.7 of IETF RFC 4187 [50]. For EAP AKA', see IETF RFC 5448 [82], the Fast Re-authentication NAI shall comply with IETF RFC 4187 [50] except that the username part of the NAI shall be prepended with single digit "8". NOTE: The permanent user identity is either the Root NAI or Decorated NAI as defined in clauses 19.3.2 and 19.3.3, respectively. EXAMPLE 1: If the fast re-authentication identity returned by the 3GPP AAA Server is 358405627015, the IMSI is 234150999999999 (MCC = 234, MNC = 15) and EAP-AKA is used, the Fast Re-authentication NAI for the case when NAI decoration is not used takes the form: 4358405627015@nai.epc.mnc015.mcc234.3gppnetwork.org EXAMPLE 2: If the fast re-authentication identity returned by the 3GPP AAA Server is "358405627015@aaa1.nai.epc.mnc015.mcc234.3gppnetwork.org" , the IMSI is 234150999999999 (MCC = 234, MNC = 15) and EAP-AKA' is used, the Fast Re-authentication NAI for the case when NAI decoration is not used takes the form: 8358405627015@aaa1.nai.epc.mnc015.mcc234.3gppnetwork.org EXAMPLE 3: If the fast re-authentication identity returned by the 3GPP AAA Server is 358405627015, the IMSI is 234150999999999 (MCC = 234, MNC = 15), the PLMN ID of the Selected PLMN is MCC = 610, MNC = 71 and EAP-AKA is used, the Fast Re-authentication NAI takes the form: nai.epc.mnc015.mcc234.3gppnetwork.org !4358405627015@nai.epc.mnc071.mcc610.3gppnetwork.org.