GTP-Control Plane

GTP-CONTROL (GPRS Tunneling Protocol-Control) is a protocol used in mobile networks for signaling purposes. It facilitates communication between various network nodes, such as the SGSN and GGSN, to manage user sessions and mobility. This protocol is essential for the proper functioning of mobile data services.

What is GTP-Control Plane

GTP-CONTROL, or GPRS Tunneling Protocol-Control, is a crucial protocol in mobile networks, particularly in the context of GPRS (General Packet Radio Service) and LTE (Long-Term Evolution) networks. It is used for signaling between network nodes, such as the Serving GPRS Support Node (SGSN) and the Gateway GPRS Support Node (GGSN). This signaling is essential for managing user sessions, mobility, and other control functions within the network.

The protocol operates over UDP and uses port 2123 for its control messages. GTP-CONTROL messages are responsible for creating, modifying, and deleting tunnels that carry user data. These tunnels are vital for ensuring that data packets are correctly routed through the mobile network, allowing users to maintain connectivity as they move between different cell towers.

Historically, GTP was developed as part of the GPRS standard to enable packet-switched data services in GSM networks. With the evolution of mobile networks to 3G and 4G, GTP has continued to play a significant role, adapting to the increased complexity and higher data rates of modern mobile communications. Companies involved in mobile network infrastructure, such as Ericsson, Nokia, and Huawei, have implemented GTP in their products to ensure seamless data services for users.

GTP-Control Plane runs on TCP and UDP port 2123 and is official IANA port.

Security risk

If port 2123 is open and the GTP-CONTROL service is running, it could be exploited by attackers to disrupt mobile network operations. Unauthorized access could lead to session hijacking, denial of service attacks, or unauthorized data interception. Proper firewall rules and network security measures are essential to mitigate these risks.

In our UFW tutorial you can follow instructions how you can configure UFW to close port 2123. Use StackChanges to monitor if the GTP-Control Plane port is closed and stays closed. StackChanges will send an alert if port 2123 is open again.