The General Packet Radio Service (GPRS) Tunneling Protocol (GTP) portable software defines the protocol between the General Packet Radio Service Support Nodes (GSNs) within the GPRS backbone network. It includes both signaling and data transfer procedures. GTP is defined for the following interfaces:

  • The Gn interface between GSNs in a Public Land Mobile Network (PLMN)
  • The Gp interface between GSNs in different PLMNs

GTP tunnels multiprotocol packets through the GPRS backbone between GSNs. In the signaling plane, GTP specifies a tunnel control and management protocol allowing the Serving GPRS Support Node (SGSN) to provide GPRS services for a Mobile Station (MS). Signaling creates, modifies and deletes tunnels.

The User Datagram Protocol (UDP) is used as the path protocol to transfer signaling messages between GSNs. In the transmission plane, GTP uses a tunneling mechanism to carry user data packets.

UNIVERSAL MOBILE TELECOMMUNICATIONS SYSTEM (UMTS)

The GTP software product also supports the user plane protocol, GTP-u, between the Radio Network Controller (RNC) in the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) and the Third Generation SGSN (3G-SGSN). At this interface, the corresponding control plane is the Radio Access Network Application Protocol (RANAP).

SUPPORTING GTP ON THE SGSN, GGSN, CGF, AND RNC

The GTP product supports the:

  • GTP, in the control and user plane, between the 2G-SGSN and 2G-GGSN across the Gn and Gp interfaces
  • GTP, in the control plane and user plane, between the 3G-SGSN and 3G-GGSN across the Gn and Gp interfaces
  • GTP user plane (GTP-u) protocol between the 2G-SGSN and 2G-GGSN
  • GTP user plane (GTP-u) protocol between the 3G-SGSN and 3G-GGSN
  • GTP-u protocol between the 3G-SGSN and RNC
  • GTP protocol between the Call Detail Record (CDR) generating the GSNs and the Charging Gateway Functionality (CGF).

CHARGING

The GTP software product supports the GTP’ across the Ga interface to reliably transfer CDR-related information between the GPRS nodes, generating the CDRs (SGSN and GGSN) and CFG. This functionality applies to both GPRS and UMTS networks.

PRODUCT INFORMATION

The GTP software is portable C source code that can be compiled to run on any processor, under any operating system, and with any system architecture. The modular design and simple interfaces allow the GTP software to be easily ported into any environment.

Trillium GTP software enables telecom equipment manufacturers of SGSNs, GGSNs, RNCs, or other products to:

  • Accelerate time to market
  • Reduce development costs
  • Reduce project risk of internally developed GTP applications

Product deliverables consist of C source software, documentation, training information, a warranty and technical support.

Extensive debugging capabilities are provided. Where terminal printing support is available, debug printing can be enabled by using compile-time and run-time options to print information about protocol flows through the layer. Further, every function call contains a trace macro at its entry that can be mapped to print information about the function invocation. This is useful in embedded systems in which other symbolic debugging is unavailable.

Extensive error-checking and recovery mechanisms make the GTP software robust enough to deal with normal error conditions. Although error checks are important, disabling them will enhance the performance of the software. In this way, the GTP software permits the user to select the granularity of error checking using compile-time options.

FEATURES + BENEFITS

Trillium GTP software provides the following capabilities.

  • Transfers the GTP control plane signaling PDUs to manage the tunneling, mobility, location, and path between the 2G-SGSN and 2G-GGSN.
  • Transfers the GTP control plane signaling PDUs to manage the tunneling, mobility, location, and path between the 3G-SGSN and 3G-GGSN.
  • Transfers the GTP control plane signaling PDUs for MBMS to manage the tunneling between the 3G-SGSN and 3G-GGSN.
  • Interacts with the GPRS DNS server for the APN Resolution to get the GGSN IP address.
  • Transfers the CDR-related information between the 2G-GSN/3G-GSN and CGF. This includes support for the transfer of LCS related CDRs in Rel 4, Rel 5, Rel 6 and Rel 7of GTP’.
  • Reliably delivers the signaling messages.
  • Provides a tunneling mechanism to carry the user data packets between the 2G-SGSN and 2G-GGSN.
  • Provides a tunneling mechanism to carry the user data packets between the 2G-SGSNs during the Inter-SGSN RA Update and Intersystem Handover procedures.
  • Provides a tunneling mechanism to carry the user data packets between the RNC and 3G-SGSN, and between the 3G-SGSN and 3G-GGSN.
  • Provides a tunneling mechanism to carry the user data packets between the source and target RNCs, during the inter-SRNC relocation procedure.
  • Checks the sequence numbers of received T-PDUs.
  • Reorders the received T-PDUs, if required, for a PDP context.
  • Reorders the received T-PDUs, if required, for a MBMS context.
  • Supports the option to distribute traffic to different IWs at a GGSN, based on a PDP type. Each instance of an IW handles the traffic for a particular PDP type.
  • Provides support for use of IPv6 node addresses in the tunnel management and charging messages.
  • Supports Intra-domain connection of RAN nodes to multiple CN nodes by allowing relay of Identity Request and SGSN Context Request to the old SGSN in the pool area.
  • Supports RAN Information Management procedure to transfer information between two BSSs through the SGSN.
  • Supports enhanced QoS for HSDPA.
  • Supports IPv6 addressing.
  • Conforms to Trillium Advanced Portability Architecture (TAPA).
  • Benefits of licensing Trillium software from Continuous Computing.

CONFORMANCE

The GTP software complies with these standards:

  • GSM 09.60, version 7.7.1, release 1998, for GTP in version 0.
  • GSM 09.60, version 7.7.0, release 1998, for GTP in version 0.
  • 3G TS 29.060, version 3.13.0, release 1999, June 2002, for GTP in version 1.
  • 3G TS 29.060, version 3.16.0, release 1999, March 2003, for GTP in version 1.
  • 3G TS 29.060, version 3.19.0, release 1999, March 2004, for GTP in version 1.
  • 3G TS 29.060, version 4.4.0, release 4, June 2002, for GTP in version 1.
  • 3G TS 29.060, version 4.7.0, release 4, March 2003, for GTP in version 1.
  • 3G TS 29.060, version 4.11.0, release 4, March 2004, for GTP in version 1.
  • 3G TS 29.060, version 5.5.0, release 5, March 2003, for GTP in version 1.
  • 3G TS 29.060, version 5.14.0, release 5, October 2005, for GTP in version 1.
  • 3G TS 29.060, version 6.0.0, release 6, March 2003, for GTP in version 1.
  • 3G TS 29.060, version 6.13.0, release 6, June 2006, for GTP in version 1.
  • 3G TS 29.060, version 7.2.0, release 7, June 2006, for GTP in version 1.
  • GSM 12.15, version 7.6.0, release 1998, for GTP’.
  • 3G TS 32.015, version 3.9.0, release 1999, June 2002, for GTP’.
  • 3G TS 32.015, version 3.11.0, release 1999, March 2003, for GTP’.
  • 3G TS 32.015, version 3.12.0, release 1999, January 2004, for GTP’.
  • 3G TS 32.215, version 4.3.0, release 4, June 2002, for GTP’.
  • 3G TS 32.215, version 4.4.0, release 4, March 2003, for GTP’.
  • 3G TS 32.215, version 4.9.0, release 5, June 2005, for GTP’.
  • 3G TS 32.215, version 5.3.0, release 5, March 2003, for GTP’.
  • 3G TS 32.215, version 5.9.0, release 5, June 2005, for GTP’.
  • 3G TS 32.251, version 6.7.0, release 6, June 2006, for GTP’.
  • 3G TS 32.251, version 7.0.1, release 7, June 2006, for GTP’.
  • 3G TS 32.298, version 6.4.1, release 6, June 2006, for GTP’.

The GTP software supports the message transport for transferring the charging information, according to 32.015 (R99), 32.215 (Rel 4 and higher), 32.251 (Rel 6 and 7) and 32.298 (Rel 6). The GTP user supports the procedures associated with the charging messages, as shown in GSM 12.15. The GTP software assumes the support of these standards, by the underlying transport layer.

  • The UDP complies with STD 0006, which transfers the GTP signalling messages and tunnels the connectionless T-PDUs.
  • Transmission Control Protocol (TCP), complies with STD 0007, is used to tunnel the connection-oriented T-PDUs.

The GTP software supports establishing the connections with the server IP hosts, as suggested in the GPRS Tunneling Protocol Specifications, GSM 09.60 and 3G TS 29.060. The address is in the form of an IP address (4-byte network address).