This topic compares the two values.
Fax machines have a special language for communicating with each other.
When a fax machine sends a fax to another machine, it includes a TSI value to let the other machine know where the fax is coming from. When a fax machine receives a fax message, it sends a CSI number to the calling machine to let it know what fax machine just received the fax. This is a way of letting the other machine know that contact was made. If you are sending a fax to another Faximum user who wants to use Incoming Fax Routing with the TSI feature, they need to know your TSI number. This is the number they will use when setting the TSI value.