摘要 |
<p>A telecommunications system for communicating internet packets between a correspondent node and a mobile node. The system comprises a packet radio network providing packet data bearers for communicating internet packets with nodes. Each of the bearers is defined with respect to a source address of the internet packets, the packet radio network including a gateway support node (GGSN) to provide an interface between the external network and the packet radio network. The GGSN detects whether an internet packet is for providing a binding update to the correspondent node of a first source address of the mobile node to a care-of-address of the mobile node. If the internet packet is a binding update, the GGSN allows egress of internet packets sent from the correspondent node. By allowing egress of packets from the correspondent node having this care-of-address as the destination address, a measure of security is provided.</p> |