Question: Which protocol is used for encapsulating a PDP PDU between Core Network Nodes in GPRS, and how is this encapsulated PDU further packaged for transmission?
Option 1: GPRS Tunnelling Protocol (GTP) header, then inserted into a UDP PDU, and finally into an IP PDU.
Option 2: Internet Protocol (IP) header directly, without any additional encapsulation for tunneling.
Option 3: User Datagram Protocol (UDP) header only, which contains necessary tunnel endpoint identifiers.
Option 4: Transmission Control Protocol (TCP) header, then into a GTP PDU, and finally into an IP PDU.
Explanation: In the context of GPRS Core Network Nodes, a PDP PDU is first encapsulated with a GTP header. This GTP PDU is then further inserted into a UDP PDU for efficient transmission over IP networks, and finally, this UDP PDU is placed within an IP PDU. The use of GTP ensures the PDP context can be uniquely addressed between nodes, while UDP and IP facilitate reliable network transmission.