Pau Espin Pedrol | f605f3d | 2017-08-31 16:32:40 +0200 | [diff] [blame] | 1 | :gfdl-enabled: |
| 2 | |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 3 | OsmoPCU Gb Protocol Specification |
| 4 | ================================= |
Max | c182b98 | 2016-03-02 16:44:13 +0100 | [diff] [blame] | 5 | Harald Welte <hwelte@sysmocom.de> |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 6 | |
| 7 | == Introduction |
| 8 | |
| 9 | This document describes the Gb interface of *OsmoPCU*. Based on 3GPP TS |
Max | c182b98 | 2016-03-02 16:44:13 +0100 | [diff] [blame] | 10 | 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] | 11 | messages and IEs are implemented according to 3GPP specifications, which of |
| 12 | these are not or not fully implemented, as well as OsmoPCU-specific extensions |
| 13 | to the Gb interface not specified by 3GPP. |
| 14 | |
| 15 | Extensions to the Gb interface specific to OsmoPCU are detailed in this |
Harald Welte | a27873f | 2016-03-10 12:35:09 +0700 | [diff] [blame] | 16 | document. For details on the messages and IEs that comply with above-mentioned |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 17 | 3GPP specifications, please refer to those documents. |
| 18 | |
| 19 | .3GPP document versions referred to by this document |
| 20 | [cols="20%,80%"] |
| 21 | |=== |
| 22 | |3GPP TS 08.56 | version 8.0.1 Release 1999 |
| 23 | |3GPP TS 08.58 | version 8.6.0 Release 1999 |
| 24 | |3GPP TS 08.60 | version 8.2.1 Release 1999 |
| 25 | |3GPP TS 12.21 | version 8.0.0 Release 1999 |
Max | c182b98 | 2016-03-02 16:44:13 +0100 | [diff] [blame] | 26 | |3GPP TS 08.16 | version 8.0.1 Release 1999 |
| 27 | |3GPP TS 08.18 | version 8.12.0 Release 1999 |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 28 | |=== |
| 29 | |
| 30 | .IETF documents referred to by his document |
| 31 | [cols="20%,80%"] |
| 32 | |=== |
| 33 | |IETF RFC 768 | User Datagram Protocol |
| 34 | |IETF RFC 791 | Internet Protocol |
| 35 | |=== |
| 36 | |
| 37 | == Overview |
| 38 | |
| 39 | The OsmoPCU Gb interface consists of the NS (Network Services) and |
| 40 | BSSGP (Base Station Subsystem Gateway Protocol), encapsulated in UDP |
| 41 | (User Datagram Protocol) and IP (Internet Protocol) version 4. |
Harald Welte | a27873f | 2016-03-10 12:35:09 +0700 | [diff] [blame] | 42 | Use of other underlying protocols (e. g. Frame Relay) is not supported. |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 43 | |
| 44 | .UDP port numbers used by OsmoPCU Gb/IP |
| 45 | [options="header",width="50%",cols="35%,65%"] |
| 46 | |=== |
| 47 | |TCP Port Number|Usage |
Harald Welte | 6fb2963 | 2016-03-10 12:53:06 +0700 | [diff] [blame] | 48 | |23000|NS over UDP (default port) |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 49 | |=== |
| 50 | |
| 51 | The NS-over-UDP link is established in the PCU -> SGSN direction, i.e. |
| 52 | the PCU is running as client while the SGSN is running as server. |
| 53 | |
| 54 | Establishment of the NS-over-UDP link is only possible after OsmoPCU |
Harald Welte | a27873f | 2016-03-10 12:35:09 +0700 | [diff] [blame] | 55 | has been configured via the *PCU socket* interface from OsmoBTS. |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 56 | |
| 57 | OsmoBTS in turn receives relevant configuration parameters from |
| 58 | OsmoBSC or the BSC component inside OsmoNITB. |
| 59 | |
| 60 | .Overview of Gb link establishment |
| 61 | ["mscgen"] |
| 62 | ---- |
Oliver Smith | 47aab58 | 2018-11-14 10:47:01 +0100 | [diff] [blame] | 63 | include::{srcdir}/gb/gb-startup.msc[] |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 64 | ---- |
| 65 | |
Max | 4e2a1e3 | 2016-03-02 18:30:33 +0100 | [diff] [blame] | 66 | [[ident]] |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 67 | === Identities |
| 68 | |
| 69 | The Gb interface identities of the PCU are configured via BSC -> |
| 70 | OsmoBTS -> PCU Socket. They consist of |
| 71 | |
| 72 | NSEI:: NS Equipment Identifier |
| 73 | NSVCI:: NS Virtual Connection Identifier |
| 74 | BVCI:: BSSGP Virtual Connection Identifier |
| 75 | |
| 76 | For an explanation of those identifiers and their use in the NS and |
Jonathan Brielmaier | 58721eb | 2016-05-25 15:01:11 +0200 | [diff] [blame] | 77 | BSSGP protocols, please see the relevant 3GPP specifications for NS (TS 08.16) |
Max | 4e2a1e3 | 2016-03-02 18:30:33 +0100 | [diff] [blame] | 78 | and BSSGP (TS 08.18). |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 79 | |
| 80 | In most cases, all above identities belong to different namespaces and |
| 81 | must be unique within their respective namespace and within the SGSN |
| 82 | they connect to. |
| 83 | |
| 84 | This means that typically each OsmoPCU has one unique set of NSEI, |
| 85 | NSVCI and BVCI in your network. |
| 86 | |
Oliver Smith | 47aab58 | 2018-11-14 10:47:01 +0100 | [diff] [blame] | 87 | include::{srcdir}/gb/ns.adoc[] |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 88 | |
Oliver Smith | 47aab58 | 2018-11-14 10:47:01 +0100 | [diff] [blame] | 89 | include::{srcdir}/gb/bssgp.adoc[] |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 90 | |
Oliver Smith | 47aab58 | 2018-11-14 10:47:01 +0100 | [diff] [blame] | 91 | include::./common/chapters/port_numbers.adoc[] |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 92 | |
Oliver Smith | 47aab58 | 2018-11-14 10:47:01 +0100 | [diff] [blame] | 93 | include::./common/chapters/glossary.adoc[] |
Harald Welte | b682cd6 | 2016-02-29 15:09:55 +0100 | [diff] [blame] | 94 | |
Oliver Smith | 47aab58 | 2018-11-14 10:47:01 +0100 | [diff] [blame] | 95 | include::./common/chapters/gfdl.adoc[] |