Section: 3.4 Mobile Station Roaming Number (MSRN) for PSTN/ISDN routeing
Content: The Mobile Station Roaming Number (MSRN) is used to route calls directed to an MS. On request from the Gateway MSC via the HLR it is temporarily allocated to an MS by the VLR with which the MS is registered; it addresses the Visited MSC collocated with the assigning VLR. More than one MSRN may be assigned simultaneously to an MS. The MSRN is passed by the HLR to the Gateway MSC to route calls to the MS. The Mobile Station Roaming Number for PSTN/ISDN routing shall have the same structure as international E.164 numbers in the area in which the roaming number is allocated, i.e.: - the country code of the country in which the visitor location register is located; - the national destination code of the visited PLMN or numbering area; - a subscriber number with the appropriate structure for that numbering area. The MSRN shall not be used for subscriber dialling. It should be noted that the MSRN can be identical to the MSISDN (clause 3.3) in certain circumstances. In order to discriminate between subscriber generated access to these numbers and re-routeing performed by the network, re-routeing or redirection indicators or other signalling means should be used, if available.