Cisco Cisco ASR 5000
Serving GPRS Support Node (SGSN) Overview
Features and Functionality ▀
SGSN Administration Guide, StarOS Release 18 ▄
On the Gb (BSSGP) interface, RIM procedures are negotiated at the start/restart of a Gb link as part of the signaling
BVC reset procedure. On the Iu (RANAP) interface, there is no negotiation for using RIM procedures. Support for RIM
procedures enhances the subscriber’s user experience by minimizing the service outage during cell re-selection.
BVC reset procedure. On the Iu (RANAP) interface, there is no negotiation for using RIM procedures. Support for RIM
procedures enhances the subscriber’s user experience by minimizing the service outage during cell re-selection.
S4 Support on the SGSN
The SGSN can provide an interface between UMTS (3G) and/or GPRS (2.5G) networks and the evolved packet core
(EPC) network. This functionality requires a special S4 feature license. Throughout the documentation the SGSN with
this additional functionality is referred to as an S4-SGSN.
(EPC) network. This functionality requires a special S4 feature license. Throughout the documentation the SGSN with
this additional functionality is referred to as an S4-SGSN.
To facilitate communication with GPRS, UMTS, and EPC networks, the SGSN is configured with standard 2.5G SGSN,
3G SGSN or dual access SGSN services, and then configured with additional enhancements to enable communication
with the EPC network.
3G SGSN or dual access SGSN services, and then configured with additional enhancements to enable communication
with the EPC network.
The S4-SGSN communicates with other UMTS and GPRS core networks elements via the GTPv1 protocol, and
communicates with EPC network elements and peer S4-SGSNs via the GTPv2 protocol. The S4-SGSN communicates
with the UMTS (3G) / GPRS (2.5G) radio access network elements in the same manner as an SGSN.
communicates with EPC network elements and peer S4-SGSNs via the GTPv2 protocol. The S4-SGSN communicates
with the UMTS (3G) / GPRS (2.5G) radio access network elements in the same manner as an SGSN.
Depending on the configured SGSN service type, the S4-SGSN can interface with some or all of the following
UMTS/GPRS and EPC network elements:
UMTS/GPRS and EPC network elements:
Serving Gateway (S-GW)
Mobility Management Entity (MME)
Peer S4-SGSN (2.5G or 3G with S4 support)
Peer dual access S4-SGSN
Peer SGSN (2.5G or 3G)
Peer dual access SGSN
GGSN
The S4-SGSN includes the following S4-SGSN specific functionality and features: