Question: In an SMS message, where is the TP-Reply-Path field located, and what does a value of '1' indicate?
Option 1: Within bit no 5 of the second octet of SMS-SUBMIT only, indicating the SMS is a reply to a Class 0 message.
Option 2: Across bits 6 & 7 of the first octet in both SMS-DELIVER and SMS-SUBMIT, signifying the use of a dedicated reply channel.
Option 3: In bit no 3 of the third octet of SMS-SUBMIT and SMS-DELIVER, showing that the message requires a delivery report.
Option 4: Within bit no 7 of the first octet of both SMS-DELIVER and SMS-SUBMIT, indicating the TP-Reply-Path parameter is set for this message.
Explanation: This answer accurately reflects the location (bit no 7 of the first octet) and implication (TP-Reply-Path parameter being set) of the TP-Reply-Path field in both SMS-DELIVER and SMS-SUBMIT messages, crucial for handling reply procedures correctly in SMS exchanges between User Equipment (UE) and Short Message Service Centers (SMSC).