Working Group Two is now part of CiscoGGSN/PGW
The gateway GPRS support node (GGSN) is one of two components of the GPRS PS domain. The GGSN together with the SGSN handle packet transmissions between the GPRS network and external packet-switched networks, such as the Internet
The Packet Data Network Gateway (PDN Gateway, also PGW) provides connectivity from the User Equipment (UE) to external packet data networks (PDNs) by being its point of exit and entry of traffic.