Cisco Cisco ASR 5000
Serving GPRS Support Node (SGSN) Overview
▀ Features and Functionality
▄ SGSN Administration Guide, StarOS Release 18
Figure 8.
TCM Algorithm Logic for Traffic Policing
VPC-DI platform support for SGSN
The traditional proprietary hardware platforms like ASR5K and ASR5500 provide carrier class hardware redundancy
and have limited scalability. The VPC-SI model separates the StarOS from the proprietary hardware. It consists of the
StarOS software running within a single VM. This provides the end user with low entry cost (software licenses and
commodity hardware), simplified setup, and well-defined interfaces. The VPC-SI is ideally suited for small carriers,
remote locations, lab testing, trials, demos, and other models where full functionality is needed. The Cisco VPC-
Distributed Instance (VPC-DI) platform allows multiple VMs to act as a single StarOS instance with shared interfaces,
shared service addresses, load balancing, redundancy, and a single point of management. The VPC-DI offers enhanced
hardware capabilities, the SGSN is enhanced to support the VPC-DI platform.
and have limited scalability. The VPC-SI model separates the StarOS from the proprietary hardware. It consists of the
StarOS software running within a single VM. This provides the end user with low entry cost (software licenses and
commodity hardware), simplified setup, and well-defined interfaces. The VPC-SI is ideally suited for small carriers,
remote locations, lab testing, trials, demos, and other models where full functionality is needed. The Cisco VPC-
Distributed Instance (VPC-DI) platform allows multiple VMs to act as a single StarOS instance with shared interfaces,
shared service addresses, load balancing, redundancy, and a single point of management. The VPC-DI offers enhanced
hardware capabilities, the SGSN is enhanced to support the VPC-DI platform.
Reordering of SNDCP N-PDU Segments
The SGSN fully supports reordering of out-of-order segments coming from the same SNDCP N-PDU. The SGSN waits
the configured amount of time for all segments of the N-PDU to arrive. If all the segments are not received before the
timer expiries, then all queued segments are dropped.
the configured amount of time for all segments of the N-PDU to arrive. If all the segments are not received before the
timer expiries, then all queued segments are dropped.
RAN Information Management (RIM)
RAN information is transferred from a source RAN node to a destination RAN node in a RIM container. This is a
mechanism for the exchange of information between applications belonging to RAN nodes, for example two BSCs. The
RIM container is transparent to the SGSN.
mechanism for the exchange of information between applications belonging to RAN nodes, for example two BSCs. The
RIM container is transparent to the SGSN.
Support for RIM procedures is optional for both the SGSN and other RAN nodes (e.g., RNC). When the SGSN supports
RIM procedures, the SGSN provides addressing, routing and relay functions. All RIM messages are routed
independently by the SGSN. The SGSN performs relaying of RIM messages between BSSGP, RANAP, and GTP in
accordance with 3GPP TS 48.018, TS25.413, and TS29.060 respectively.
RIM procedures, the SGSN provides addressing, routing and relay functions. All RIM messages are routed
independently by the SGSN. The SGSN performs relaying of RIM messages between BSSGP, RANAP, and GTP in
accordance with 3GPP TS 48.018, TS25.413, and TS29.060 respectively.