A.1 Rules for building RANAP messages

25.4133GPPRelease 17TSUTRAN Iu interface Radio Access Network Application Part (RANAP) signalling

A.1.1 Rules for RANAP messages that shall contain the CN Domain Indicator IE

Based on the principles described in TS 25.401 [3], the following rules can be deduced:

1) The following RANAP messages initiating a connection oriented signalling connection shall contain the CN Domain Indicator IE: INITIAL UE MESSAGE message and RELOCATION REQUEST message.

2) Any RANAP message belonging to class 1 procedures and which uses connectionless signalling shall contain the CN Domain Indicator IE.

3) The following RANAP messages belonging to class 2 procedures and using connectionless signalling shall contain the CN Domain Indicator IE: PAGING message and ERROR INDICATION message, the OVERLOAD message in DL direction (see chapter 8.25.3.1) may contain the CN Domain Indicator IE.