Question: In a UTRAN Iu interface using UDP/IP, how are RTP and RTCP protocols associated with port numbers for a single Iu UP connection?
Option 1: A single port number is used for both RTP and RTCP, with the protocol type indicated in the packet header.
Option 2: Two consecutive port numbers (a "port number block") are used, with the even number assigned to RTP and the next (odd) number reserved for RTCP.
Option 3: The RNC dynamically assigns a port number to RTP and another to RTCP based on availability at the time of connection setup.
Option 4: Only one port number is assigned for both RTP and RTCP, but with different UDP socket configurations.
Explanation: According to the specified telecom standards for UTRAN Iu interface data transport, to efficiently manage and distinguish between RTP (Real-time Transport Protocol) and RTCP (Real-time Transport Control Protocol) in a single Iu UP connection, two consecutive port numbers are allocated. This "port number block" ensures streamlined communication: the first (even) port is dedicated to RTP for media transfer, while the immediately following (odd) port is reserved for RTCP, which manages the transmission, even if RTCP is not actively in use. This structured approach simplifies connection management and enhances reliability in telecom networks.