SGSN (Serving GPRS Support Node)

What is SGSN (Serving GPRS Support Node)?

GGSNs, or Gateway GPRS Support Nodes, are a component of the core network that links 3G networks based on GSM to the Internet. The Serving GPRS Support Node (SGSN) and the GGSN collaborate to keep mobile users connected to the Internet and IP-based applications. The GGSN is also sometimes referred to as a wireless router.

The GPRS support nodes are made up of the GGSN and the SGSN. Incoming data traffic from mobile users is converted by the GGSN (via the SGSN) and forwarded to the appropriate network.  The GGSN is also connected to the core network's billing, policy management, and user verification systems, as well as hosted services (such as voice and video).

How does SGSN work?

SGSN is responsible for the two-way exchange of data packets containing information between a mobile phone user and the destination network inside the SGSN’s geographical area.

Mobile data is made possible by SGSN's provision of packet-switched functionality to UMTS and GSM networks. Mobile phones operating in a certain geographic area serviced by an SGSN can send and receive data packets with information content. Data that SGSN receives from mobile customers is forwarded to GGSN. Before transferring the data to the intended external network, GGSN converts the data into an appropriate protocol format. The process is reversed on the way back. Therefore, before being sent to the mobile phone user, the data is first received from the external network in that network's format and then converted by GGSN into a protocol format that mobile phones can understand.

Difference between SGSN and GGSN

Within the 2G GSM and 3G UMTS networks, the mobile core network nodes known as SGSN and GGSN enable packet-switched mobile data. Data from a mobile user is received by GGSN via SGSN, converted into the appropriate protocol format, and sent to the external data network. This process is reversed on the way back.

What are the advantages of SGSN?

Benefits of SGSN include its switching functionality, security and authentication features.