Question: What is the correct format for deriving the Mobile Network Code (MNC) with less than 3 significant digits in an ANDSF-SN, when contacting either a Visited or Home ANDSF?
Option 1: Truncate the MNC to its most significant digit.
Option 2: Append a "0" digit at the right side to fill the 3 digits coding of MNC.
Option 3: Use only alphanumeric characters to represent the MNC in the DNS format.
Option 4: Insert a "0" digit at the left side to fill the 3 digits coding of MNC in the ANDSF-SN.
Explanation: To maintain consistency and ensure proper DNS translation across different PLMNs, the 3GPP standard requires that the MNC be represented by exactly 3 digits in the ANDSF-SN format. If an MNC has only 2 significant digits, padding with a "0" on the left (i.e., leading zero) is necessary to meet this requirement, as exemplified in the ANDSF-SN format "andsf.mnc012.mcc345.pub.3gppnetwork.org". This approach ensures uniformity and facilitates accurate inter-PLMN DNS translations.