SS7 SCCP and TCAP support the non-connection-oriented messaging transactions required by IN. The operation of SCCP and TCAP were outlined in Chapter 3 and we now illustrate the message coding details for a typical IN transaction. In fact the particular message flow illustrated here is for a mobile call involving a CAP (CAMEL application protocol) request. As we discussed earlier, there is strong equivalence between the CAP and the INAP protocols. There are some application parameter differences, but the behaviour of SCCP and TCAP in support of the messaging is identical in both cases and so the illustration here would be similar for an INAP transaction scenario. We show the messaging required for a call where the IN service logic requests the SSF (the gsmSSF in this case) for end of call notification. This might be used, for instance, where the SCF needs to log the call's duration, perhaps in order to decrement the customer's prepaid account by the cost of the call.