2.15.1.2 Interaction

ITU-International linksets do not have a group code. ITU-National or Spare MSUs received on ITU-International linksets are assigned a group code of aa.

Gateway Screening has no impact of group codes support. However, the user can effectively screen on group codes by assigning a different screenset to linksets that have different group codes.

Each ITU-N destination and group code can have it’s own ITU-I or ANSI alias PC. Each ITU-I or ANSI node can be assigned one ITU-N destination. For conversion from ITU-I or ANSI to ITU-N to succeed, the ITU-N alias of the sending node must have the same group code as the destination group code. So each ITU-I or ANSI node can only send and receive messages from one ITU-N group.