Trillium | SubNetwork-Dependent Convergence Protocol (SNDCP)
Description
The General Packet Radio Service (GPRS) uses the SubNetwork-Dependent Convergence Protocol (SNDCP) layer services. SNDCP can operate within the Mobile Station (MS) or Serving GPRS Support Node (SGSN) depending on the option selected by the customer.
Trillium SNDCP software enables telecom equipment manufacturers of soft switches, signaling gateways, signal transfer points, service control points, media gateway controllers or other products to:
- Accelerate time to market
- Reduce development costs
- Reduce project risk of internally developed SDNCP applications
Product deliverables consist of C source software, documentation, training, a warranty and technical support.
Features + Benefits
- Allows software architectural flexibility by receiving uplink traffic at the SGSN from multiple instances of LLC. The SNDCP software also receives downlink traffic at the SGSN from multiple instances of the SNDCP user.
- Distributes uplink traffic at SGSN to multiple instances of an SNDCP user and distributes downlink traffic at SGSN to multiple instances of LLC.
- Multiplexes Network Protocol Data Units (N-PDUs) from several network layer entities onto the appropriate LLC connection.
- Establishes, reestablishes and releases acknowledged peer-to-peer LLC operations.
- Transfers acknowledged and unacknowledged information.
- Manages delivery sequences for each Network Service Access Point ID (NSAPI) independently.
- Manages compression entities. SNDCP maintains a compression entity for an algorithm type with a specific set of parameters on each SAPI, at the request of its service user (NSAPI). To conserve resources, multiple users (NSAPIs) can access the same compression entity if they use the same SAPI and compression parameters. There is a separate entity for acknowledged and unacknowledged operations. The customer provides the compression algorithm. Trillium SNDCP software provides an Application Program Interface for the compression algorithm.
- Buffers N-PDUs for acknowledged mode services. SNDCP buffers N-PDUs until LLC acknowledges them in the acknowledged mode of operation.
- Segments and reassembles the user PDU.
- Negotiates eXchange Identification (XID) parameters between peer SNDCP entities using XID exchange.
- Performs congestion control by transmitting N-PDUs to LLC based on the precedence class of Packet Data Protocol (PDP) contexts.
- Buffers N-PDUs in the acknowledged mode when LLC reports congestion.
- Performs buffer retrieval during an inter-SGSN Routing Area (RA) update.
- Conforms to Trillium Advanced Portability Architecture (TAPA)
- Benefits of licensing Trillium software from Continuous Computing
Product Interworking
Trillium SNDCP software interworks with Trillium Logical Link Control (LLC) software.
Professional Services
Continuous Computing also offers Trillium Professional Services to integrate Trillium software into customers' products.
Conformance
Trillium SNDCP software conforms to the following standard:
- SubNetwork-Dependent Convergence Protocol (SNDCP), ETSI, GSM 04.65, Release 98
