A problem in OpenBSC, sccp.c

Hello, I have a problem in sccp.c. 537--543 udt->type = SCCP_MSG_TYPE_UDT; udt->proto_class = class; udt->variable_called = 3; udt->variable_calling = 5 + out->gti_len; if(out->use_poi) udt->variable_calling += 2; udt->variable_data = 7 + out->gti_len + in->gti_len; if(in->use_poi) udt->variable_calling += 2; I add these two 'if' lines in the code. I'm not sure if it is right. In source code, before it calls 'create_sccp_addr', it sets the length only using gti_len. But in 'create_sccp_addr', if I use poi, the length should be add 2. Am I right?