Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 1 | OsmoPCU Gb Protocol Specification |
| 2 | ================================= |
Max | c182b98 | 2016-03-02 16:44:13 +0100 | [diff] [blame] | 3 | Harald Welte <hwelte@sysmocom.de> |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 4 | |
| 5 | == Introduction |
| 6 | |
| 7 | This document describes the Gb interface of *OsmoPCU*. Based on 3GPP TS |
Max | c182b98 | 2016-03-02 16:44:13 +0100 | [diff] [blame] | 8 | 08.16 and 08.18, this document indicates which of the 3GPP specified Gb |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 9 | messages and IEs are implemented according to 3GPP specifications, which of |
| 10 | these are not or not fully implemented, as well as OsmoPCU-specific extensions |
| 11 | to the Gb interface not specified by 3GPP. |
| 12 | |
| 13 | Extensions to the Gb interface specific to OsmoPCU are detailed in this |
| 14 | document. For details on the messages and IEs that comply with abovementioned |
| 15 | 3GPP specifications, please refer to those documents. |
| 16 | |
| 17 | .3GPP document versions referred to by this document |
| 18 | [cols="20%,80%"] |
| 19 | |=== |
| 20 | |3GPP TS 08.56 | version 8.0.1 Release 1999 |
| 21 | |3GPP TS 08.58 | version 8.6.0 Release 1999 |
| 22 | |3GPP TS 08.60 | version 8.2.1 Release 1999 |
| 23 | |3GPP TS 12.21 | version 8.0.0 Release 1999 |
Max | c182b98 | 2016-03-02 16:44:13 +0100 | [diff] [blame] | 24 | |3GPP TS 08.16 | version 8.0.1 Release 1999 |
| 25 | |3GPP TS 08.18 | version 8.12.0 Release 1999 |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 26 | |=== |
| 27 | |
| 28 | .IETF documents referred to by his document |
| 29 | [cols="20%,80%"] |
| 30 | |=== |
| 31 | |IETF RFC 768 | User Datagram Protocol |
| 32 | |IETF RFC 791 | Internet Protocol |
| 33 | |=== |
| 34 | |
| 35 | == Overview |
| 36 | |
| 37 | The OsmoPCU Gb interface consists of the NS (Network Services) and |
| 38 | BSSGP (Base Station Subsystem Gateway Protocol), encapsulated in UDP |
| 39 | (User Datagram Protocol) and IP (Internet Protocol) version 4. |
Max | 4e2a1e3 | 2016-03-02 18:30:33 +0100 | [diff] [blame^] | 40 | Use of other underlying protocols (e. g. FrameRelay) is not supported. |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 41 | |
| 42 | .UDP port numbers used by OsmoPCU Gb/IP |
| 43 | [options="header",width="50%",cols="35%,65%"] |
| 44 | |=== |
| 45 | |TCP Port Number|Usage |
| 46 | |23000|NS over UDP |
| 47 | |=== |
| 48 | |
| 49 | The NS-over-UDP link is established in the PCU -> SGSN direction, i.e. |
| 50 | the PCU is running as client while the SGSN is running as server. |
| 51 | |
| 52 | Establishment of the NS-over-UDP link is only possible after OsmoPCU |
| 53 | has been configured viat the *PCU socket* interface from OsmoBTS. |
| 54 | |
| 55 | OsmoBTS in turn receives relevant configuration parameters from |
| 56 | OsmoBSC or the BSC component inside OsmoNITB. |
| 57 | |
| 58 | .Overview of Gb link establishment |
| 59 | ["mscgen"] |
| 60 | ---- |
| 61 | include::gb/gb-startup.msc[] |
| 62 | ---- |
| 63 | |
Max | 4e2a1e3 | 2016-03-02 18:30:33 +0100 | [diff] [blame^] | 64 | [[ident]] |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 65 | === Identities |
| 66 | |
| 67 | The Gb interface identities of the PCU are configured via BSC -> |
| 68 | OsmoBTS -> PCU Socket. They consist of |
| 69 | |
| 70 | NSEI:: NS Equipment Identifier |
| 71 | NSVCI:: NS Virtual Connection Identifier |
| 72 | BVCI:: BSSGP Virtual Connection Identifier |
| 73 | |
| 74 | For an explanation of those identifiers and their use in the NS and |
Max | 4e2a1e3 | 2016-03-02 18:30:33 +0100 | [diff] [blame^] | 75 | BSSGP protocols, please see the reelvant 3GPP specifications for NS (TS 08.16) |
| 76 | and BSSGP (TS 08.18). |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 77 | |
| 78 | In most cases, all above identities belong to different namespaces and |
| 79 | must be unique within their respective namespace and within the SGSN |
| 80 | they connect to. |
| 81 | |
| 82 | This means that typically each OsmoPCU has one unique set of NSEI, |
| 83 | NSVCI and BVCI in your network. |
| 84 | |
| 85 | include::gb/ns.adoc[] |
| 86 | |
| 87 | include::gb/bssgp.adoc[] |
| 88 | |
| 89 | include::../common/chapters/port_numbers.adoc[] |
| 90 | |
| 91 | include::../common/chapters/glossary.adoc[] |
| 92 | |
| 93 | include::../common/chapters/gfdl.adoc[] |