If you mean the signalling traffic , then the below is my understanding.
One IN call either on INAP or CAP contains an avg of 5 MSUs of 110 octets per MSU without any “Connect to resource “message.This implies a very high signalling traffic over IN links.The announcement traffic again is very high for announcement systems.If the announcement system is inbuilt to the switch/SSP then oughtmost care is to be taken for it.For any specific details mail radhakant_das@rediffmail.com.