General Packet Radio Service (GPRS); Serving GPRS Support Node (SGSN) - Visitors Location Register (VLR); Gs interface network service specification
The present document specifies or references the subset of MTP and SCCP which is used for the reliable transport of BSSAP+ messages in the Gs interface. The present document references the 3GPP TS 29.202 which specifies alternative transport layers that can be applied instead of the MTP. The present document also specifies the SCCP addressing capabilities to be provided in the Gs interface.
The present document is divided into two main parts, clause 5 dealing with the use of MTP and clauses 6 and 7 dealing with the use of SCCP.
Clause 5 of the present document deals with the subset of the MTP that is required between an SGSN and a VLR. It is intended that this implementation of MTP is compatible with a full MTP implementation. Clause 4 references the 3GPP TS 29.202 which specifies alternatives to the MTP.
The SCCP is used to provide message routing between the SGSN and the VLR. The SCCP routing principles specified in the present document allow to connect one SGSN to several VLR. No segmentation at SCCP level is needed on the Gs interface. Only SCCP class 0 is used on the Gs interface. Clauses 6 and 7 identify the SCCP subset that should be used between an SGSN and an VLR.