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-rw-r--r--doc/BS11-OML.txt31
-rw-r--r--doc/Makefile.am3
-rw-r--r--doc/call-routing.txt25
-rw-r--r--doc/channel_release.txt95
-rw-r--r--doc/e1-data-model.txt172
-rw-r--r--doc/examples/Makefile.am22
-rw-r--r--doc/examples/osmo-bsc/osmo-bsc.cfg106
-rw-r--r--doc/examples/osmo-bsc_mgcp/mgcp.cfg19
-rw-r--r--doc/examples/osmo-bsc_nat/black-list.cfg1
-rw-r--r--doc/examples/osmo-bsc_nat/bscs.config13
-rw-r--r--doc/examples/osmo-bsc_nat/osmo-bsc_nat.cfg66
-rw-r--r--doc/examples/osmo-gbproxy/osmo-gbproxy-legacy.cfg44
-rw-r--r--doc/examples/osmo-gbproxy/osmo-gbproxy.cfg25
-rw-r--r--doc/examples/osmo-gtphub/gtphub-example.txt90
-rw-r--r--doc/examples/osmo-gtphub/osmo-gtphub-1iface.cfg25
-rw-r--r--doc/examples/osmo-gtphub/osmo-gtphub.cfg25
-rw-r--r--doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx-hopping.cfg164
-rw-r--r--doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx.cfg84
-rw-r--r--doc/examples/osmo-nitb/bs11/openbsc-2bts-2trx.cfg148
-rw-r--r--doc/examples/osmo-nitb/bs11/openbsc.cfg56
-rw-r--r--doc/examples/osmo-nitb/nanobts/openbsc-multitrx.cfg99
-rw-r--r--doc/examples/osmo-nitb/nanobts/openbsc.cfg77
-rw-r--r--doc/examples/osmo-nitb/nokia/openbsc_nokia_3trx.cfg117
-rw-r--r--doc/examples/osmo-nitb/rbs2308/openbsc.cfg220
-rw-r--r--doc/examples/osmo-nitb/sysmobts/openbsc.cfg77
-rw-r--r--doc/examples/osmo-sgsn/osmo-sgsn.cfg26
-rw-r--r--doc/gsm-hopping.txt54
-rw-r--r--doc/handover.txt89
-rw-r--r--doc/ipa-sccp.txt94
-rw-r--r--doc/oml-interface.txt22
-rw-r--r--doc/osmo-nitb-data_structures.dot33
-rw-r--r--doc/paging.txt48
32 files changed, 2170 insertions, 0 deletions
diff --git a/doc/BS11-OML.txt b/doc/BS11-OML.txt
new file mode 100644
index 000000000..e5c3299c9
--- /dev/null
+++ b/doc/BS11-OML.txt
@@ -0,0 +1,31 @@
+The Siemens BS-11 supports the following additional GSM 12.21 OML operations:
+
+
+CREATE OBJECT
+
+abis_om_fom_hdr.obj_class can be
+A3:
+A5: ALCO, BBSIG, CCLK, GPSU, LI, PA
+A8: EnvaBTSE
+A9: BPORT
+
+the abis_om_obj_inst.trx_nr field indicates the index of object, whereas the
+abis_om_fom_hdr.bts_nr indicates the type of the object.
+
+enum abis_bs11_objtype {
+ BS11_OBJ_ALCO = 0x01,
+ BS11_OBJ_BBSIG = 0x02, /* obj_class: 0,1 */
+ BS11_OBJ_TRX1 = 0x03, /* only DEACTIVATE TRX1 */
+ BS11_OBJ_CCLK = 0x04,
+ BS11_OBJ_GPSU = 0x06,
+ BS11_OBJ_LI = 0x07,
+ BS11_OBJ_PA = 0x09, /* obj_class: 0, 1*/
+};
+
+In case of CREATE ENVABTSE, the abis_om_obj_inst.trx_nr indicates the EnvaBTSEx
+number.
+
+In case of A9 (CREAETE BPORT), the abis_om_obj_inst.bts_nr indicates which BPORT
+shall be used.
+
+
diff --git a/doc/Makefile.am b/doc/Makefile.am
new file mode 100644
index 000000000..5a231074c
--- /dev/null
+++ b/doc/Makefile.am
@@ -0,0 +1,3 @@
+SUBDIRS = \
+ examples \
+ $(NULL)
diff --git a/doc/call-routing.txt b/doc/call-routing.txt
new file mode 100644
index 000000000..3402f9e33
--- /dev/null
+++ b/doc/call-routing.txt
@@ -0,0 +1,25 @@
+Call routing in OpenBSC
+
+Flow of events:
+
+ # MO call initiated by MS, CHANNEL RQD, IMMEDIATE ASSIGN
+ # MS sends CC SETUP message, we assume already on TCH/H FACCH
+ # OpenBSC does a subscriber lookup based on the target extension
+ * If a subscriber is found:
+ # send CALL PROCEEDING message to MO
+ # page the MT subscriber and ask itI to ask for TCH/H
+ # once paging completes, we have the TCH/H for the MT end
+ # send SETUP to MT
+ # receive CALL CONFIRMED from MT
+ # set-up the TRAU mux mapping between the E1 subslots for both TCH/H
+ # receive ALERTING from MT, route ALERTING to MO
+ # receive CONNECT from MT, confirm to MT with CONNECT_ACK
+ # send a CONNECT message to MO, receive CONNECT_ACK from MO
+ * If subscriber is not found:
+ # send RELEASE COMPLETE with apropriate cause to MO (1: unalloacated 3: no route)
+
+
+
+Thoughts about RR/MM:
+
+* we allocate RR/MM entities on demand, when we need them
diff --git a/doc/channel_release.txt b/doc/channel_release.txt
new file mode 100644
index 000000000..c9cdfebca
--- /dev/null
+++ b/doc/channel_release.txt
@@ -0,0 +1,95 @@
+
+GSM 04.08 7.1.7 / 9.1.7 RR CHANNEL RELESE
+
+RSL 08.58 3.4 / ? RLL Link Release Request
+
+RSL 08.58 4.6 / 8.4.5 DEACTivate SACCH
+ * Deactivate SACCH according to Channel Release Proc 04.08
+ * to be sent after RR CHANNEL RELEASE is sent to MS
+
+RSL 08.58 4.7 / 8.4.14 RF CHANnel RELease
+ * tells the BTS to release a radio channel
+ * "when an activated radio channel is no longer needed"
+ * BTS responds with RF CHANnel RELease ACKnowledge
+
+
+GSM 04.08 3.4.13: RR connection release procedure
+
+* network sends RR CHANNEL RELEASE to MS on the DCCH
+ * start T3109
+ * deactivate SACCH
+* MS disconnects main signalling link (by sending DISC)
+ * all other data links are disconnected by local end link release
+* network receives DISC (BTS sends RLL REL IND to BSC)
+ * stop T3109
+ * start T3111
+* when T3111 times out, the network can reuse the channls
+* if T3109 times out, the network deactivates the channels
+ and can reuse them
+ * this probably means simply RF CHANnel RELease
+
+
+== Implementation in OpenBSC ==
+
+There are two possible reasons a gsm_subscriber_connection
+will be released. One is a network failure, the other is
+the completion of an operation/transaction.
+
+=== Failure ===
+The BSC API will call the gsm_04_08.c:gsm0408_clear_request callback
+and the MSC part will release all transactions, operations and such
+and the channels will be released as error case.
+
+=== Success ===
+Every time an 'operation' or 'transaction' is finished msc_release_connection
+will be called and it will determine if the gsm_subscriber_connection can
+be released.
+
+In case it can be released bsc_api.c:gsm0808_clear will be called
+which will release all lchan's associated with the connection. For the
+primary channel a SACH Deactivate will be send with the release
+reason NORMAL RELEASE.
+
+
+bsc_api.c:gsm0808_clear
+ * Release a channel used for handover
+ * Release the primary lchan with normal release, SACH deactivate
+
+chan_alloc.c:lchan_release(chan, sacch_deactivate, reason)
+ * Start the release procedure. It is working in steps with callbacks
+ coming from the abis_rsl.c code.
+ * Release all SAPI's > 0 as local end (The BTS should send a
+ REL_CONF a message)
+ * Send SACH Deactivate on SAPI=0 if required.
+ * Start T3109 (stop it when the main signalling link is disconnected)
+ or when the channel released. On timeout start the error handling.
+ * abis_rsl.c schedules the RSL_MT_RF_CHAN_REL once all SAPI's are
+ released and after T3111 has timed out or there is an error.
+
+RX of RELease INDication:
+ * Calls internal rsl_handle_release which might release the RF.
+
+RX of RELease CONFirmation:
+ * Calls internal rsl_handle_release which might release the RF.
+
+* RX of RF_CHAN_REL_ACK
+ * call lchan_free()
+
+
+=== Integration with SMS ===
+
+* RX of CP_ERROR or unimplemented MT
+ * trigger trans_free() which will msc_release_connection()
+
+* CP TC1* expired while waiting for CP-ACK
+ * trigger trans_free() which will msc_release_connection()
+
+* RX of RP_ERROR
+ * trigger trans_free() which will msc_release_connection()
+
+* TX of CP-ACK in MT DELIVER
+ * trigger trans_free() which will msc_release_connection()
+
+* RX of CP-ACK in MO SUBMIT
+ * trigger trans_free() which will msc_release_connection()
+
diff --git a/doc/e1-data-model.txt b/doc/e1-data-model.txt
new file mode 100644
index 000000000..509004fe9
--- /dev/null
+++ b/doc/e1-data-model.txt
@@ -0,0 +1,172 @@
+E1 related data model
+
+This data model describes the physical relationship of the individual
+parts in the network, it is not the logical/protocol side of the GSM
+network.
+
+A BTS is connected to the BSC by some physical link. It could be an actual
+E1 link, but it could also be abis-over-IP with a mixture of TCP and RTP/UDP.
+
+To further complicate the fact, multiple BTS can share one such pysical
+link. On a single E1 line, we can easily accomodate up to three BTS with
+two TRX each.
+
+Thus, it is best for OpenBSC to have some kind of abstraction layer. The BSC's
+view of a BTS connected to it. We call this 'bts_link'. A bts_link can be
+* all the TCP and UDP streams of a Abis-over-IP BTS
+* a set of E1 timeslots for OML, RSL and TRAU connections on a E1 link
+* a serial line exclusively used for OML messages (T-Link)
+
+A bts_link can be registered with the OpenBSC core at runtime.
+
+struct trx_link {
+ struct gsm_bts_trx *trx;
+};
+
+struct bts_link {
+ struct gsm_bts *bts;
+ struct trx_link trx_links[NUM_TRX];
+};
+
+Interface from stack to input core:
+======================================================================
+int abis_rsl_sendmsg(struct msgb *msg);
+ send a message through a RSL link to the TRX specified by the caller in
+ msg->trx.
+
+int abis_rsl_rcvmsg(struct msgb *msg);
+ receive a message from a RSL link from the TRX specified by the
+ caller in msg->trx.
+
+int abis_nm_sendmsg(struct msgb *msg);
+ send a message through a OML link to the BTS specified by the caller in
+ msg->trx->bts. The caller can just use bts->c0 to get the first TRX
+ in a BTS. (OML messages are not really sent to a TRX but to the BTS)
+
+int abis_nm_rcvmsg(struct msgb *msg);
+ receive a message from a OML link from the BTS specified by the caller
+ in msg->trx->bts. The caller can just use bts->c0 to get the first
+ TRX in a BTS.
+
+int abis_link_event(int event, void *data);
+ signal some event (such as layer 1 connect/disconnect) from the
+ input core to the stack.
+
+int subch_demux_in(mx, const uint8_t *data, int len);
+ receive 'len' bytes from a given E1 timeslot (TRAU frames)
+
+int subchan_mux_out(mx, uint8_t *data, int len);
+ obtain 'len' bytes of output data to be sent on E1 timeslot
+
+Intrface by Input Core for Input Plugins
+======================================================================
+
+int btslink_register_plugin();
+
+
+Configuration for the E1 input module
+======================================================================
+
+BTS
+ BTS number
+ number of TRX
+ OML link
+ E1 line number
+ timeslot number
+ [subslot number]
+ SAPI
+ TEI
+ for each TRX
+ RSL link
+ E1 line number
+ timeslot number
+ [subslot number]
+ SAPI
+ TEI
+ for each TS
+ E1 line number
+ timeslot number
+ subslot number
+
+
+E1 input module data model
+======================================================================
+
+
+enum e1inp_sign_type {
+ E1INP_SIGN_NONE,
+ E1INP_SIGN_OML,
+ E1INP_SIGN_RSL,
+};
+
+struct e1inp_sign_link {
+ /* list of signalling links */
+ struct llist_head list;
+
+ enum e1inp_sign_type type;
+
+ /* trx for msg->trx of received msgs */
+ struct gsm_bts_trx *trx;
+
+ /* msgb queue of to-be-transmitted msgs */
+ struct llist_head tx_list;
+
+ /* SAPI and TEI on the E1 TS */
+ uint8_t sapi;
+ uint8_t tei;
+}
+
+enum e1inp_ts_type {
+ E1INP_TS_TYPE_NONE,
+ E1INP_TS_TYPE_SIGN,
+ E1INP_TS_TYPE_TRAU,
+};
+
+/* A timeslot in the E1 interface */
+struct e1inp_ts {
+ enum e1inp_ts_type type;
+ struct e1inp_line *line;
+ union {
+ struct {
+ struct llist_head sign_links;
+ } sign;
+ struct {
+ /* subchannel demuxer for frames from E1 */
+ struct subch_demux demux;
+ /* subchannel muxer for frames to E1 */
+ struct subch_mux mux;
+ } trau;
+ };
+ union {
+ struct {
+ /* mISDN driver has one fd for each ts */
+ struct osmo_fd;
+ } misdn;
+ } driver;
+};
+
+struct e1inp_line {
+ unsigned int num;
+ char *name;
+
+ struct e1inp_ts ts[NR_E1_TS];
+
+ char *e1inp_driver;
+ void *driver_data;
+};
+
+/* Call from the Stack: configuration of this TS has changed */
+int e1inp_update_ts(struct e1inp_ts *ts);
+
+/* Receive a packet from the E1 driver */
+int e1inp_rx_ts(struct e1inp_ts *ts, struct msgb *msg,
+ uint8_t tei, uint8_t sapi);
+
+/* Send a packet, callback function in the driver */
+int e1driver_tx_ts(struct e1inp_ts *ts, struct msgb *msg)
+
+
+struct e1inp_driver {
+ const char *name;
+ int (*want_write)(struct e1inp_ts *ts);
+};
diff --git a/doc/examples/Makefile.am b/doc/examples/Makefile.am
new file mode 100644
index 000000000..530c3fa8f
--- /dev/null
+++ b/doc/examples/Makefile.am
@@ -0,0 +1,22 @@
+CFG_FILES = find $(srcdir) -name '*.cfg*' | sed -e 's,^$(srcdir),,'
+
+dist-hook:
+ for f in $$($(CFG_FILES)); do \
+ j="$(distdir)/$$f" && \
+ mkdir -p "$$(dirname $$j)" && \
+ $(INSTALL_DATA) $(srcdir)/$$f $$j; \
+ done
+
+install-data-hook:
+ for f in $$($(CFG_FILES)); do \
+ j="$(DESTDIR)$(docdir)/examples/$$f" && \
+ mkdir -p "$$(dirname $$j)" && \
+ $(INSTALL_DATA) $(srcdir)/$$f $$j; \
+ done
+
+uninstall-hook:
+ @$(PRE_UNINSTALL)
+ for f in $$($(CFG_FILES)); do \
+ j="$(DESTDIR)$(docdir)/examples/$$f" && \
+ $(RM) $$j; \
+ done
diff --git a/doc/examples/osmo-bsc/osmo-bsc.cfg b/doc/examples/osmo-bsc/osmo-bsc.cfg
new file mode 100644
index 000000000..56e47243b
--- /dev/null
+++ b/doc/examples/osmo-bsc/osmo-bsc.cfg
@@ -0,0 +1,106 @@
+!
+! OsmoBSC (0.9.14+gitr1+3d331c0062bb0c9694dbd4d1eab7adc58138c3ae) configuration saved from vty
+!!
+password foo
+!
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver ipa
+network
+ network country code 1
+ mobile network code 1
+ short name OsmoBSC
+ long name OsmoBSC
+ auth policy closed
+ location updating reject cause 13
+ encryption a5 0
+ neci 1
+ paging any use tch 0
+ rrlp mode none
+ mm info 1
+ handover 0
+ handover window rxlev averaging 10
+ handover window rxqual averaging 1
+ handover window rxlev neighbor averaging 10
+ handover power budget interval 6
+ handover power budget hysteresis 3
+ handover maximum distance 9999
+ timer t3101 10
+ timer t3103 0
+ timer t3105 0
+ timer t3107 0
+ timer t3109 0
+ timer t3111 0
+ timer t3113 60
+ timer t3115 0
+ timer t3117 0
+ timer t3119 0
+ timer t3122 0
+ timer t3141 0
+ subscriber-keep-in-ram 0
+ bts 0
+ type nanobts
+ band DCS1800
+ cell_identity 0
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ ms max power 15
+ cell reselection hysteresis 4
+ rxlev access min 0
+ channel allocator ascending
+ rach tx integer 9
+ rach max transmission 7
+ dtx uplink force
+ dtx downlink
+ ip.access unit_id 0 0
+ oml ip.access stream_id 255 line 0
+ neighbor-list mode manual-si5
+ neighbor-list add arfcn 100
+ neighbor-list add arfcn 200
+ si5 neighbor-list add arfcn 10
+ si5 neighbor-list add arfcn 20
+ gprs mode none
+ trx 0
+ rf_locked 0
+ arfcn 871
+ nominal power 23
+ max_power_red 20
+ rsl e1 tei 0
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ hopping enabled 0
+ timeslot 1
+ phys_chan_config TCH/F
+ hopping enabled 0
+ timeslot 2
+ phys_chan_config TCH/F
+ hopping enabled 0
+ timeslot 3
+ phys_chan_config TCH/F
+ hopping enabled 0
+ timeslot 4
+ phys_chan_config TCH/F
+ hopping enabled 0
+ timeslot 5
+ phys_chan_config TCH/F
+ hopping enabled 0
+ timeslot 6
+ phys_chan_config TCH/F
+ hopping enabled 0
+ timeslot 7
+ phys_chan_config TCH/F
+ hopping enabled 0
+msc
+ ip.access rtp-base 4000
+ timeout-ping 20
+ timeout-pong 5
+ dest 192.168.100.11 6666 0
+ access-list-name msc-list
+ no access-list-name
+bsc
+ no access-list-name
+ access-list-name bsc-list
diff --git a/doc/examples/osmo-bsc_mgcp/mgcp.cfg b/doc/examples/osmo-bsc_mgcp/mgcp.cfg
new file mode 100644
index 000000000..791497f84
--- /dev/null
+++ b/doc/examples/osmo-bsc_mgcp/mgcp.cfg
@@ -0,0 +1,19 @@
+!
+! MGCP configuration hand edited
+! !
+password foo
+!
+line vty
+ no login
+!
+mgcp
+! local ip 213.167.134.14
+ bts ip 172.16.252.43
+ bind ip 127.0.0.1
+ bind port 2427
+ rtp base 4000
+ rtp force-ptime 20
+ sdp audio payload number 98
+ sdp audio payload name AMR/8000
+ number endpoints 31
+ loop 1
diff --git a/doc/examples/osmo-bsc_nat/black-list.cfg b/doc/examples/osmo-bsc_nat/black-list.cfg
new file mode 100644
index 000000000..d36179d37
--- /dev/null
+++ b/doc/examples/osmo-bsc_nat/black-list.cfg
@@ -0,0 +1 @@
+678012512671923:6:6:
diff --git a/doc/examples/osmo-bsc_nat/bscs.config b/doc/examples/osmo-bsc_nat/bscs.config
new file mode 100644
index 000000000..176debe42
--- /dev/null
+++ b/doc/examples/osmo-bsc_nat/bscs.config
@@ -0,0 +1,13 @@
+nat
+ bsc 0
+ token lol
+ location_area_code 1234
+ description bsc
+ max-endpoints 32
+ paging forbidden 0
+ bsc 1
+ token wat
+ location_area_code 5678
+ description bsc
+ max-endpoints 32
+ paging forbidden 0
diff --git a/doc/examples/osmo-bsc_nat/osmo-bsc_nat.cfg b/doc/examples/osmo-bsc_nat/osmo-bsc_nat.cfg
new file mode 100644
index 000000000..6b48e970e
--- /dev/null
+++ b/doc/examples/osmo-bsc_nat/osmo-bsc_nat.cfg
@@ -0,0 +1,66 @@
+!
+! OsmoBSCNAT (0.12.0.266-2daa9) configuration saved from vty
+!!
+!
+log stderr
+ logging filter all 1
+ logging color 1
+ logging timestamp 0
+ logging level all debug
+ logging level rll notice
+ logging level cc notice
+ logging level mm notice
+ logging level rr notice
+ logging level rsl notice
+ logging level nm info
+ logging level mncc notice
+ logging level pag notice
+ logging level meas notice
+ logging level sccp notice
+ logging level msc notice
+ logging level mgcp notice
+ logging level ho notice
+ logging level db notice
+ logging level ref notice
+ logging level gprs debug
+ logging level ns info
+ logging level bssgp debug
+ logging level llc debug
+ logging level sndcp debug
+ logging level nat notice
+ logging level ctrl notice
+ logging level smpp debug
+ logging level lglobal notice
+ logging level llapd notice
+ logging level linp notice
+ logging level lmux notice
+ logging level lmi notice
+ logging level lmib notice
+ logging level lsms notice
+!
+line vty
+ no login
+!
+mgcp
+ bind ip 0.0.0.0
+ bind port 2427
+ rtp bts-base 4000
+ rtp net-base 16000
+ rtp ip-dscp 0
+ no rtcp-omit
+ sdp audio-payload number 126
+ sdp audio-payload name AMR/8000
+ loop 0
+ number endpoints 1
+ call-agent ip 127.0.0.1
+ rtp transcoder-base 0
+ transcoder-remote-base 4000
+nat
+ msc ip 127.0.0.1
+ msc port 5000
+ timeout auth 2
+ timeout ping 20
+ timeout pong 5
+ ip-dscp 0
+ bscs-config-file bscs.config
+ access-list bla imsi-allow ^11$
diff --git a/doc/examples/osmo-gbproxy/osmo-gbproxy-legacy.cfg b/doc/examples/osmo-gbproxy/osmo-gbproxy-legacy.cfg
new file mode 100644
index 000000000..15fd74a2b
--- /dev/null
+++ b/doc/examples/osmo-gbproxy/osmo-gbproxy-legacy.cfg
@@ -0,0 +1,44 @@
+!
+! OsmoGbProxy (UNKNOWN) configuration saved from vty
+!!
+!
+log stderr
+ logging filter all 1
+ logging color 1
+ logging timestamp 0
+ logging level all debug
+ logging level gprs debug
+ logging level ns info
+ logging level bssgp debug
+ logging level lglobal notice
+ logging level llapd notice
+ logging level linp notice
+ logging level lmux notice
+ logging level lmi notice
+ logging level lmib notice
+ logging level lsms notice
+!
+line vty
+ no login
+!
+ns
+ nse 666 nsvci 666
+ nse 666 remote-role sgsn
+! nse 666 encapsulation framerelay-gre
+! nse 666 remote-ip 172.16.1.70
+! nse 666 fr-dlci 666
+ timer tns-block 3
+ timer tns-block-retries 3
+ timer tns-reset 3
+ timer tns-reset-retries 3
+ timer tns-test 30
+ timer tns-alive 3
+ timer tns-alive-retries 10
+ encapsulation udp local-port 23000
+! encapsulation framerelay-gre enabled 1
+gbproxy
+ sgsn nsei 666
+ core-mobile-country-code 666
+ core-mobile-network-code 6
+ core-access-point-name none match-imsi ^666066|^66607
+ tlli-list max-length 200
diff --git a/doc/examples/osmo-gbproxy/osmo-gbproxy.cfg b/doc/examples/osmo-gbproxy/osmo-gbproxy.cfg
new file mode 100644
index 000000000..0c3917a3e
--- /dev/null
+++ b/doc/examples/osmo-gbproxy/osmo-gbproxy.cfg
@@ -0,0 +1,25 @@
+!
+! Osmocom Gb Proxy (0.9.0.404-6463) configuration saved from vty
+!!
+!
+line vty
+ no login
+!
+gbproxy
+ sgsn nsei 101
+ns
+ nse 101 nsvci 101
+ nse 101 remote-role sgsn
+ nse 101 encapsulation udp
+ nse 101 remote-ip 192.168.100.239
+ nse 101 remote-port 7777
+ timer tns-block 3
+ timer tns-block-retries 3
+ timer tns-reset 3
+ timer tns-reset-retries 3
+ timer tns-test 30
+ timer tns-alive 3
+ timer tns-alive-retries 10
+ encapsulation framerelay-gre enabled 0
+ encapsulation framerelay-gre local-ip 0.0.0.0
+ encapsulation udp local-port 23000
diff --git a/doc/examples/osmo-gtphub/gtphub-example.txt b/doc/examples/osmo-gtphub/gtphub-example.txt
new file mode 100644
index 000000000..9c65f925f
--- /dev/null
+++ b/doc/examples/osmo-gtphub/gtphub-example.txt
@@ -0,0 +1,90 @@
+Here is a simple setup to test GTPHub operations. The IP addresses picked will
+work well only on a system that creates local addresses (127.0.0.123) on the
+fly (like linux) -- you may pick of course different IP addresses.
+
+Overview of the example setup:
+
+ sgsnemu gtphub ggsn
+ 127.0.0.1 <--> 127.0.0.3 127.0.0.4 <--> 127.0.0.2
+
+Prerequisites: openggsn.
+
+Have a local directory where you store config files and from which you launch
+the GSNs and the hub (they will store restart counter files in that dir).
+In it, have these config files:
+
+ggsn.conf:
+
+ # GGSN local address
+ listen 127.0.0.2
+
+ # End User Addresses are picked from this range
+ net 10.23.42.0/24
+
+ pcodns1 8.8.8.8
+
+ logfile /tmp/foo
+
+gtphub.conf:
+
+ gtphub
+ bind-to-sgsns 127.0.0.3
+ bind-to-ggsns 127.0.0.4
+ ggsn-proxy 127.0.0.2
+ end
+
+
+(
+You may omit the ggsn-proxy if GRX ares is working, or if you add the GRX
+address and GGSN IP address to /etc/hosts something like:
+
+ 127.0.0.2 internet.mnc070.mcc901.gprs
+
+)
+
+
+Once the config files are in place, start the programs, in separate terminals.
+GGSN and SGSN need to be started with root priviliges to be able to create tun
+interfaces. GTPHub may run as unprivileged user.
+
+The LD_LIBRARY_PATH below may be needed if OpenGGSN installed to /usr/local.
+
+
+1. GGSN:
+
+ sudo -s
+ cd <your-test-dir>
+ LD_LIBRARY_PATH=/usr/local/lib /usr/local/bin/ggsn -f -c ./ggsn.conf
+
+2. GTPHub:
+
+ cd <your-test-dir>
+ path/to/openbsc/openbsc/src/gprs/osmo-gtphub -c gtphub.conf #-e 1 #for DEBUG level
+
+3. SGSN tests:
+
+ sudo -s
+ cd <your-test-dir>
+ /usr/local/bin/sgsnemu --createif -l 127.0.0.1 -r 127.0.0.3 --imsi 420001214365100 --contexts=3
+
+Add more SGSNs using different IMSIs and local ports (if the same IMSI is used,
+the GGSN will reuse TEIs and tunnels will be discarded automatically):
+
+ /usr/local/bin/sgsnemu --createif -l 127.0.0.11 -r 127.0.0.3 --imsi 420001214365300 --contexts=3
+
+This shows the basic setup of GTPHub. Testing internet traffic via sgsnemu
+still needs some effort to announce a mobile subscriber or the like (I have
+used a real BTS, osmo-sgsn and a testing SIM in a web phone, instead).
+
+The core capability of GTPHub is to manage more than two GSNs, e.g. an SGSN
+contacting various GGSNs over the single GTPHub link. You would configure the
+SGSN to use one fixed GGSN (sending to gtphub) and gtphub will resolve the
+GGSNs once it has received the messages. So the SGSN may be behind NAT (add
+"sgsn-use-sender" to gtphub.conf) and communicate to various GGSNs over a
+single link to gtphub.
+
+I hope this helps to get you going.
+Any suggestions/patches are welcome!
+
+~Neels
+
diff --git a/doc/examples/osmo-gtphub/osmo-gtphub-1iface.cfg b/doc/examples/osmo-gtphub/osmo-gtphub-1iface.cfg
new file mode 100644
index 000000000..3913d2c3c
--- /dev/null
+++ b/doc/examples/osmo-gtphub/osmo-gtphub-1iface.cfg
@@ -0,0 +1,25 @@
+!
+! Osmocom gtphub configuration
+!
+! This file is used for VTY tests, referenced by openbsc/osmoappdesc.py
+! For the test, try to use most config commands.
+!
+
+line vty
+ no login
+
+gtphub
+ ! Local addresses to listen on and send from, both on one interface.
+ ! The side towards SGSN uses nonstandard ports.
+ bind-to-sgsns ctrl 127.0.0.1 12123 user 127.0.0.1 12153
+ ! The GGSN side with standard ports.
+ bind-to-ggsns 127.0.0.1
+
+ ! Proxy: unconditionally direct all traffic to...
+ sgsn-proxy 127.0.0.4
+
+ ! Proxy with nonstandard ports or separate IPs:
+ ggsn-proxy ctrl 127.0.0.3 2123 user 127.0.0.5 2152
+
+ ! Add a name server for GGSN resolution
+ grx-dns-add 192.168.0.1
diff --git a/doc/examples/osmo-gtphub/osmo-gtphub.cfg b/doc/examples/osmo-gtphub/osmo-gtphub.cfg
new file mode 100644
index 000000000..0dc415047
--- /dev/null
+++ b/doc/examples/osmo-gtphub/osmo-gtphub.cfg
@@ -0,0 +1,25 @@
+!
+! Osmocom gtphub configuration
+!
+
+line vty
+ no login
+
+gtphub
+ ! Local addresses to listen on and send from, each on standard ports
+ ! 2123 and 2152. Setting these addresses is mandatory.
+ bind-to-sgsns 127.0.0.1
+ bind-to-ggsns 127.0.0.2
+
+ ! Local nonstandard ports or separate IPs:
+ !bind-to-sgsns ctrl 127.0.0.1 2342 user 127.0.0.1 4223
+
+ ! Proxy: unconditionally direct all traffic to...
+ !ggsn-proxy 127.0.0.3
+ !sgsn-proxy 127.0.0.4
+
+ ! Proxy with nonstandard ports or separate IPs:
+ !ggsn-proxy ctrl 127.0.0.3 2123 user 127.0.0.5 2152
+
+ ! Add a name server for GGSN resolution
+ !grx-dns-add 192.168.0.1
diff --git a/doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx-hopping.cfg b/doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx-hopping.cfg
new file mode 100644
index 000000000..673064491
--- /dev/null
+++ b/doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx-hopping.cfg
@@ -0,0 +1,164 @@
+!
+! OpenBSC (0.9.0.845-57c4) configuration saved from vty
+!!
+password foo
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver misdn
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ auth policy closed
+ location updating reject cause 13
+ encryption a5 0
+ neci 1
+ rrlp mode none
+ mm info 0
+ handover 0
+ handover window rxlev averaging 10
+ handover window rxqual averaging 1
+ handover window rxlev neighbor averaging 10
+ handover power budget interval 6
+ handover power budget hysteresis 3
+ handover maximum distance 9999
+ timer t3101 10
+ timer t3103 0
+ timer t3105 0
+ timer t3107 0
+ timer t3109 4
+ timer t3111 0
+ timer t3113 60
+ timer t3115 0
+ timer t3117 0
+ timer t3119 0
+ timer t3141 0
+ bts 0
+ type bs11
+ band GSM900
+ cell_identity 0
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ ms max power 15
+ cell reselection hysteresis 4
+ rxlev access min 0
+ channel allocator descending
+ rach tx integer 9
+ rach max transmission 7
+ oml e1 line 0 timeslot 1 sub-slot full
+ oml e1 tei 25
+ gprs mode none
+ trx 0
+ rf_locked 0
+ arfcn 121
+ nominal power 24
+ max_power_red 12
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 1
+ timeslot 0
+ phys_chan_config CCCH
+ hopping enabled 0
+ e1 line 0 timeslot 1 sub-slot full
+ timeslot 1
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 2 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 2 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 2 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 3
+ trx 1
+ rf_locked 0
+ arfcn 119
+ nominal power 24
+ max_power_red 12
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 2
+ timeslot 0
+ phys_chan_config SDCCH8
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ timeslot 1
+ phys_chan_config TCH/F
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ e1 line 0 timeslot 4 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ e1 line 0 timeslot 4 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ e1 line 0 timeslot 4 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ e1 line 0 timeslot 5 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ e1 line 0 timeslot 5 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ e1 line 0 timeslot 5 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ hopping enabled 1
+ hopping sequence-number 0
+ hopping maio 0
+ hopping arfcn add 117
+ hopping arfcn add 119
+ e1 line 0 timeslot 5 sub-slot 3
diff --git a/doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx.cfg b/doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx.cfg
new file mode 100644
index 000000000..ca5689fd5
--- /dev/null
+++ b/doc/examples/osmo-nitb/bs11/openbsc-1bts-2trx.cfg
@@ -0,0 +1,84 @@
+!
+! OpenBSC configuration saved from vty
+! !
+password foo
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver misdn
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ timer t3101 10
+ timer t3113 60
+ bts 0
+ type bs11
+ band GSM900
+ cell_identity 1
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ oml e1 line 0 timeslot 1 sub-slot full
+ oml e1 tei 25
+ trx 0
+ arfcn 121
+ max_power_red 0
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 1
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ e1 line 0 timeslot 1 sub-slot full
+ timeslot 1
+ phys_chan_config SDCCH8
+ e1 line 0 timeslot 2 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 3
+ trx 1
+ arfcn 123
+ max_power_red 0
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 2
+ timeslot 0
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 3
diff --git a/doc/examples/osmo-nitb/bs11/openbsc-2bts-2trx.cfg b/doc/examples/osmo-nitb/bs11/openbsc-2bts-2trx.cfg
new file mode 100644
index 000000000..4f194c00c
--- /dev/null
+++ b/doc/examples/osmo-nitb/bs11/openbsc-2bts-2trx.cfg
@@ -0,0 +1,148 @@
+!
+! OpenBSC configuration saved from vty
+! !
+password foo
+!
+line vty
+ no login
+!
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ timer t3101 10
+ timer t3113 60
+ bts 0
+ type bs11
+ band GSM900
+ cell_identity 1
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ oml e1 line 0 timeslot 1 sub-slot full
+ oml e1 tei 25
+ trx 0
+ arfcn 121
+ max_power_red 0
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 1
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ e1 line 0 timeslot 1 sub-slot full
+ timeslot 1
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 3
+ trx 1
+ arfcn 123
+ max_power_red 0
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 2
+ timeslot 0
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 4 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 5 sub-slot 3
+ bts 1
+ type bs11
+ band GSM900
+ location_area_code 2
+ training_sequence_code 7
+ base_station_id_code 63
+ oml e1 line 1 timeslot 6 sub-slot full
+ oml e1 tei 25
+ trx 0
+ arfcn 122
+ max_power_red 0
+ rsl e1 line 1 timeslot 6 sub-slot full
+ rsl e1 tei 1
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ e1 line 1 timeslot 7 sub-slot 0
+ timeslot 1
+ phys_chan_config SDCCH8
+ e1 line 1 timeslot 7 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 7 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 7 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 8 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 8 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 8 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 8 sub-slot 3
+ trx 1
+ arfcn 124
+ max_power_red 0
+ rsl e1 line 1 timeslot 6 sub-slot full
+ rsl e1 tei 2
+ timeslot 0
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 9 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 9 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 9 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 9 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 10 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 10 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 10 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 1 timeslot 10 sub-slot 3
diff --git a/doc/examples/osmo-nitb/bs11/openbsc.cfg b/doc/examples/osmo-nitb/bs11/openbsc.cfg
new file mode 100644
index 000000000..6c47a902d
--- /dev/null
+++ b/doc/examples/osmo-nitb/bs11/openbsc.cfg
@@ -0,0 +1,56 @@
+!
+! OpenBSC configuration saved from vty
+! !
+password foo
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver misdn
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ timer t3101 10
+ timer t3113 60
+ bts 0
+ type bs11
+ band GSM900
+ cell_identity 1
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ oml e1 line 0 timeslot 1 sub-slot full
+ oml e1 tei 25
+ trx 0
+ arfcn 121
+ max_power_red 0
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 1
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ e1 line 0 timeslot 1 sub-slot full
+ timeslot 1
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 2 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 3 sub-slot 3
+
diff --git a/doc/examples/osmo-nitb/nanobts/openbsc-multitrx.cfg b/doc/examples/osmo-nitb/nanobts/openbsc-multitrx.cfg
new file mode 100644
index 000000000..3277bea56
--- /dev/null
+++ b/doc/examples/osmo-nitb/nanobts/openbsc-multitrx.cfg
@@ -0,0 +1,99 @@
+!
+! OpenBSC configuration saved from vty
+! !
+password foo
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver ipa
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ auth policy closed
+ location updating reject cause 13
+ encryption a5 0
+ neci 1
+ rrlp mode none
+ mm info 0
+ handover 0
+ handover window rxlev averaging 10
+ handover window rxqual averaging 1
+ handover window rxlev neighbor averaging 10
+ handover power budget interval 6
+ handover power budget hysteresis 3
+ handover maximum distance 9999
+ timer t3101 10
+ timer t3103 0
+ timer t3105 0
+ timer t3107 0
+ timer t3109 4
+ timer t3111 0
+ timer t3113 60
+ timer t3115 0
+ timer t3117 0
+ timer t3119 0
+ timer t3141 0
+ bts 0
+ type nanobts
+ band DCS1800
+ cell_identity 0
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ ms max power 15
+ cell reselection hysteresis 4
+ rxlev access min 0
+ channel allocator ascending
+ rach tx integer 9
+ rach max transmission 7
+ ip.access unit_id 1800 0
+ oml ip.access stream_id 255 line 0
+ gprs mode none
+ trx 0
+ rf_locked 0
+ arfcn 871
+ nominal power 23
+ max_power_red 0
+ rsl e1 tei 0
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ timeslot 1
+ phys_chan_config SDCCH8
+ timeslot 2
+ phys_chan_config TCH/F
+ timeslot 3
+ phys_chan_config TCH/F
+ timeslot 4
+ phys_chan_config TCH/F
+ timeslot 5
+ phys_chan_config TCH/F
+ timeslot 6
+ phys_chan_config TCH/F
+ timeslot 7
+ phys_chan_config TCH/F
+ trx 1
+ rf_locked 0
+ arfcn 873
+ nominal power 23
+ max_power_red 0
+ rsl e1 tei 0
+ timeslot 0
+ phys_chan_config SDCCH8
+ timeslot 1
+ phys_chan_config TCH/F
+ timeslot 2
+ phys_chan_config TCH/F
+ timeslot 3
+ phys_chan_config TCH/F
+ timeslot 4
+ phys_chan_config TCH/F
+ timeslot 5
+ phys_chan_config TCH/F
+ timeslot 6
+ phys_chan_config TCH/F
+ timeslot 7
+ phys_chan_config TCH/F
diff --git a/doc/examples/osmo-nitb/nanobts/openbsc.cfg b/doc/examples/osmo-nitb/nanobts/openbsc.cfg
new file mode 100644
index 000000000..cfc1be6b0
--- /dev/null
+++ b/doc/examples/osmo-nitb/nanobts/openbsc.cfg
@@ -0,0 +1,77 @@
+!
+! OpenBSC configuration saved from vty
+! !
+password foo
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver ipa
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ auth policy closed
+ location updating reject cause 13
+ encryption a5 0
+ neci 1
+ rrlp mode none
+ mm info 1
+ handover 0
+ handover window rxlev averaging 10
+ handover window rxqual averaging 1
+ handover window rxlev neighbor averaging 10
+ handover power budget interval 6
+ handover power budget hysteresis 3
+ handover maximum distance 9999
+ timer t3101 10
+ timer t3103 0
+ timer t3105 0
+ timer t3107 0
+ timer t3109 4
+ timer t3111 0
+ timer t3113 60
+ timer t3115 0
+ timer t3117 0
+ timer t3119 0
+ timer t3141 0
+ bts 0
+ type nanobts
+ band DCS1800
+ cell_identity 0
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ ms max power 15
+ cell reselection hysteresis 4
+ rxlev access min 0
+ channel allocator ascending
+ rach tx integer 9
+ rach max transmission 7
+ ip.access unit_id 1801 0
+ oml ip.access stream_id 255 line 0
+ gprs mode none
+ trx 0
+ rf_locked 0
+ arfcn 514
+ nominal power 23
+ max_power_red 20
+ rsl e1 tei 0
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ timeslot 1
+ phys_chan_config SDCCH8
+ timeslot 2
+ phys_chan_config TCH/F
+ timeslot 3
+ phys_chan_config TCH/F
+ timeslot 4
+ phys_chan_config TCH/F
+ timeslot 5
+ phys_chan_config TCH/F
+ timeslot 6
+ phys_chan_config TCH/F
+ timeslot 7
+ phys_chan_config TCH/F
diff --git a/doc/examples/osmo-nitb/nokia/openbsc_nokia_3trx.cfg b/doc/examples/osmo-nitb/nokia/openbsc_nokia_3trx.cfg
new file mode 100644
index 000000000..90386bec2
--- /dev/null
+++ b/doc/examples/osmo-nitb/nokia/openbsc_nokia_3trx.cfg
@@ -0,0 +1,117 @@
+!
+! OpenBSC configuration saved from vty
+! !
+password foo
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver misdn
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ timer t3101 10
+ timer t3113 60
+ bts 0
+ type nokia_site
+ band GSM1800
+ cell_identity 1
+ location_area_code 1
+ base_station_id_code 63
+ training_sequence_code 7
+
+ oml e1 line 0 timeslot 1 sub-slot full
+ oml e1 tei 1
+
+ trx 0
+ arfcn 866
+ max_power_red 24
+ rsl e1 line 0 timeslot 2 sub-slot full
+ rsl e1 tei 1
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ e1 line 0 timeslot 6 sub-slot full
+ timeslot 1
+ phys_chan_config SDCCH8
+ e1 line 0 timeslot 6 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 6 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 6 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 7 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 7 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 7 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 7 sub-slot 3
+
+ trx 1
+ arfcn 870
+ max_power_red 24
+ rsl e1 line 0 timeslot 3 sub-slot full
+ rsl e1 tei 2
+ timeslot 0
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 8 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 8 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 8 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 8 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 9 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 9 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 9 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 9 sub-slot 3
+
+ trx 2
+ arfcn 874
+ max_power_red 24
+ rsl e1 line 0 timeslot 4 sub-slot full
+ rsl e1 tei 3
+ timeslot 0
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 10 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 10 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 10 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 10 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 11 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 11 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 11 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ e1 line 0 timeslot 11 sub-slot 3
diff --git a/doc/examples/osmo-nitb/rbs2308/openbsc.cfg b/doc/examples/osmo-nitb/rbs2308/openbsc.cfg
new file mode 100644
index 000000000..0226920e1
--- /dev/null
+++ b/doc/examples/osmo-nitb/rbs2308/openbsc.cfg
@@ -0,0 +1,220 @@
+!
+! OpenBSC (0.9.11.308-62d46) configuration saved from vty
+!!
+password foo
+!
+line vty
+ no login
+!
+network
+ network country code 262
+ mobile network code 42
+ short name OpenBSC
+ long name OpenBSC
+ auth policy closed
+ location updating reject cause 13
+ encryption a5 0
+ neci 0
+ paging any use tch 0
+ rrlp mode none
+ mm info 0
+ handover 0
+ handover window rxlev averaging 10
+ handover window rxqual averaging 1
+ handover window rxlev neighbor averaging 10
+ handover power budget interval 6
+ handover power budget hysteresis 3
+ handover maximum distance 9999
+ timer t3101 10
+ timer t3103 0
+ timer t3105 0
+ timer t3107 0
+ timer t3109 4
+ timer t3111 0
+ timer t3113 60
+ timer t3115 0
+ timer t3117 0
+ timer t3119 0
+ timer t3122 0
+ timer t3141 0
+ subscriber-keep-in-ram 0
+ bts 0
+ type rbs2000
+ band GSM900
+ cell_identity 0
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ ms max power 15
+ cell reselection hysteresis 4
+ rxlev access min 0
+ channel allocator descending
+ rach tx integer 9
+ rach max transmission 7
+ oml e1 line 0 timeslot 1 sub-slot full
+ oml e1 tei 62
+ neighbor-list mode automatic
+ gprs mode none
+ is-connection-list add 4 512 12
+ is-connection-list add 16 524 12
+ is-connection-list add 28 536 12
+ is-connection-list add 40 548 12
+ trx 0
+ rf_locked 0
+ arfcn 55
+ nominal power 24
+ max_power_red 12
+ rsl e1 line 0 timeslot 1 sub-slot full
+ rsl e1 tei 0
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ hopping enabled 0
+ e1 line 0 timeslot 1 sub-slot full
+ timeslot 1
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 2 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 2 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 2 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 3 sub-slot 3
+ trx 1
+ rf_locked 0
+ arfcn 57
+ nominal power 24
+ max_power_red 12
+ rsl e1 line 0 timeslot 4 sub-slot full
+ rsl e1 tei 1
+ timeslot 0
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 5 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 5 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 5 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 5 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 6 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 6 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 6 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 6 sub-slot 3
+ trx 2
+ rf_locked 0
+ arfcn 59
+ nominal power 24
+ max_power_red 12
+ rsl e1 line 0 timeslot 7 sub-slot full
+ rsl e1 tei 2
+ timeslot 0
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 8 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 8 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 8 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 8 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 9 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 9 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 9 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 9 sub-slot 3
+ trx 3
+ rf_locked 0
+ arfcn 61
+ nominal power 24
+ max_power_red 12
+ rsl e1 line 0 timeslot 10 sub-slot full
+ rsl e1 tei 3
+ timeslot 0
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 11 sub-slot 0
+ timeslot 1
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 11 sub-slot 1
+ timeslot 2
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 11 sub-slot 2
+ timeslot 3
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 11 sub-slot 3
+ timeslot 4
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 12 sub-slot 0
+ timeslot 5
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 12 sub-slot 1
+ timeslot 6
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 12 sub-slot 2
+ timeslot 7
+ phys_chan_config TCH/F
+ hopping enabled 0
+ e1 line 0 timeslot 12 sub-slot 3
+
+e1_input
+ e1_line 0 driver dahdi
diff --git a/doc/examples/osmo-nitb/sysmobts/openbsc.cfg b/doc/examples/osmo-nitb/sysmobts/openbsc.cfg
new file mode 100644
index 000000000..7c078f63d
--- /dev/null
+++ b/doc/examples/osmo-nitb/sysmobts/openbsc.cfg
@@ -0,0 +1,77 @@
+!
+! OpenBSC configuration saved from vty
+! !
+password foo
+!
+line vty
+ no login
+!
+e1_input
+ e1_line 0 driver ipa
+network
+ network country code 1
+ mobile network code 1
+ short name OpenBSC
+ long name OpenBSC
+ auth policy closed
+ location updating reject cause 13
+ encryption a5 0
+ neci 1
+ rrlp mode none
+ mm info 1
+ handover 0
+ handover window rxlev averaging 10
+ handover window rxqual averaging 1
+ handover window rxlev neighbor averaging 10
+ handover power budget interval 6
+ handover power budget hysteresis 3
+ handover maximum distance 9999
+ timer t3101 10
+ timer t3103 0
+ timer t3105 0
+ timer t3107 0
+ timer t3109 4
+ timer t3111 0
+ timer t3113 60
+ timer t3115 0
+ timer t3117 0
+ timer t3119 0
+ timer t3141 0
+ bts 0
+ type sysmobts
+ band DCS1800
+ cell_identity 0
+ location_area_code 1
+ training_sequence_code 7
+ base_station_id_code 63
+ ms max power 15
+ cell reselection hysteresis 4
+ rxlev access min 0
+ channel allocator ascending
+ rach tx integer 9
+ rach max transmission 7
+ ip.access unit_id 1801 0
+ oml ip.access stream_id 255 line 0
+ gprs mode none
+ trx 0
+ rf_locked 0
+ arfcn 514
+ nominal power 23
+ max_power_red 20
+ rsl e1 tei 0
+ timeslot 0
+ phys_chan_config CCCH+SDCCH4
+ timeslot 1
+ phys_chan_config SDCCH8
+ timeslot 2
+ phys_chan_config TCH/F
+ timeslot 3
+ phys_chan_config TCH/F
+ timeslot 4
+ phys_chan_config TCH/F
+ timeslot 5
+ phys_chan_config TCH/F
+ timeslot 6
+ phys_chan_config TCH/F
+ timeslot 7
+ phys_chan_config TCH/F
diff --git a/doc/examples/osmo-sgsn/osmo-sgsn.cfg b/doc/examples/osmo-sgsn/osmo-sgsn.cfg
new file mode 100644
index 000000000..49559830a
--- /dev/null
+++ b/doc/examples/osmo-sgsn/osmo-sgsn.cfg
@@ -0,0 +1,26 @@
+!
+! Osmocom SGSN configuration
+!
+!
+line vty
+ no login
+!
+sgsn
+ gtp local-ip 127.0.0.1
+ ggsn 0 remote-ip 127.0.0.1
+ ggsn 0 gtp-version 1
+!
+ns
+ timer tns-block 3
+ timer tns-block-retries 3
+ timer tns-reset 3
+ timer tns-reset-retries 3
+ timer tns-test 30
+ timer tns-alive 3
+ timer tns-alive-retries 10
+ encapsulation udp local-ip 127.0.0.1
+ encapsulation udp local-port 23000
+ encapsulation framerelay-gre enabled 0
+!
+bssgp
+!
diff --git a/doc/gsm-hopping.txt b/doc/gsm-hopping.txt
new file mode 100644
index 000000000..c964963c0
--- /dev/null
+++ b/doc/gsm-hopping.txt
@@ -0,0 +1,54 @@
+according to GSM 05.02:
+
+general parameters from CCCH:
+* CA cell allocation of ARFCN's (System Information / BCCH)
+* FN: TDMA frame number (t1,t2,t3') in SCH
+
+specific parameters from channel assignment:
+* MA: mobile allocation, defines set of ARFCN's, up to 64
+* MAIO: index
+* HSN: hopping sequence generator number (0..64)
+
+
+hopping sequence generation (6.2.3):
+
+uint8_t rntable[114] = {
+ 48, 98, 63, 1, 36, 95, 78, 102, 94, 73,
+ 0, 64, 25, 81, 76, 59, 124, 23, 104, 100,
+ 101, 47, 118, 85, 18, 56, 96, 86, 54, 2,
+ 80, 34, 127, 13, 6, 89, 57, 103, 12, 74,
+ 55, 111, 75, 38, 109, 71, 112, 29, 11, 88,
+ 87, 19, 3, 68, 110, 26, 33, 31, 8, 45,
+ 82, 58, 40, 107, 32, 5, 106, 92, 62, 67,
+ 77, 108, 122, 37, 60, 66, 121, 42, 51, 126,
+ 117, 114, 4, 90, 43, 52, 53, 113, 120, 72,
+ 16, 49, 7, 79, 119, 61, 22, 84, 9, 97,
+ 125, 99, 17, 123
+};
+
+/* mai=0 represents lowest ARFCN in the MA */
+
+
+uint8_t hopping_mai(uint8_t hsn, uint32_t fn, uint8_t maio,
+ uint8_t t1, uint8_t t2, uint8_t t3_)
+{
+ uint8_t mai;
+
+ if (hsn == 0) /* cyclic hopping */
+ mai = (fn + maio) % n;
+ else {
+ uint32_t m, m_, t_, s;
+
+ m = t2 + rntable[(hsn xor (t1 % 64)) + t3];
+ m_ = m % (2^NBIN);
+ t_ = t3 % (2^NBIN);
+ if (m_ < n then)
+ s = m_;
+ else
+ s = (m_ + t_) % n;
+ mai = (s + maio) % n;
+ }
+
+ return mai;
+}
+
diff --git a/doc/handover.txt b/doc/handover.txt
new file mode 100644
index 000000000..ac19e8725
--- /dev/null
+++ b/doc/handover.txt
@@ -0,0 +1,89 @@
+Ideas about a handover algorithm
+======================================================================
+
+This is mostly based on the results presented in Chapter 8 of "Performance
+Enhancements in a Frequency Hopping GSM Network" by Thomas Toftegaard Nielsen
+and Joeroen Wigard.
+
+
+=== Reasons for performing handover ===
+
+Section 2.1.1: Handover used in their CAPACITY simulation:
+
+1) Interference Handover
+
+Average RXLEV is satisfactory high, but average RXQUAL too low indicates
+interference to the channel. Handover should be made.
+
+2) Bad Quality
+
+Averaged RXQUAL is lower than a threshold
+
+3) Low Level / Signal Strength
+
+Average RXLEV is lower than a threshold
+
+4) Distance Handover
+
+MS is too far away from a cell (measured by TA)
+
+5) Power budget / Better Cell
+
+RX Level of neighbor cell is at least "HO Margin dB" dB better than the
+current serving cell.
+
+=== Ideal parameters for HO algorithm ===
+
+Chapter 8, Section 2.2, Table 24:
+
+Window RXLEV averaging: 10 SACCH frames (no weighting)
+Window RXQUAL averaging: 1 SACCH frame (no averaging)
+Level Threashold: 1 of the last 1 AV-RXLEV values < -110dBm
+Quality Threshold: 3 of the last 4 AV-RXQUAL values >= 5
+Interference Threshold: 1 of the last AV-RXLEV > -85 dBm &
+ 3 of the last 4 AV-RXQUAL values >= 5
+Power Budget: Level of neighbor cell > 3 dB better
+Power Budget Interval: Every 6 SACCH frames (6 seconds ?!?)
+Distance Handover: Disabled
+Evaluation rule 1: RXLEV of the candidate cell a tleast -104 dBm
+Evaluation rule 2: Level of candidate cell > 3dB better own cell
+Timer Successful HO: 5 SACCH frames
+Timer Unsuccessful HO: 1 SACCH frame
+
+In a non-frequency hopping case, RXQUAL threshold can be decreased to
+RXLEV >= 4
+
+When frequency hopping is enabled, the following additional parameters
+should be introduced:
+
+* No intra-cell handover
+* Use a HO Margin of 2dB
+
+=== Handover Channel Reservation ===
+
+In loaded network, each cell should reserve some channels for handovers,
+rather than using all of them for new call establishment. This reduces the
+need to drop calls due to failing handovers, at the expense of failing new call
+attempts.
+
+=== Dynamic HO Margin ===
+
+The handover margin (hysteresis) should depend on the RXQUAL. Optimal results
+were achieved with the following settings:
+* RXQUAL <= 4: 9 dB
+* RXQUAL == 5: 6 dB
+* RXQUAL >= 6: 1 dB
+
+
+
+== Actual Handover on a protocol level ==
+
+After the BSC has decided a handover shall be done, it has to
+
+# allocate a channel at the new BTS
+# allocate a handover reference
+# activate the channel on the BTS side using RSL CHANNEL ACTIVATION,
+ indicating the HO reference
+# BTS responds with CHAN ACT ACK, including GSM frame number
+# BSC sends 04.08 HO CMD to MS using old BTS
+
diff --git a/doc/ipa-sccp.txt b/doc/ipa-sccp.txt
new file mode 100644
index 000000000..5d6719e98
--- /dev/null
+++ b/doc/ipa-sccp.txt
@@ -0,0 +1,94 @@
+
+IPA SCCP message flow in the BSC
+
+February, 2013 Holger Hans Peter Freyther
+
+CONTENTS
+
+1. SCCP inside the IPA header
+2. Supported SCCP message types
+3. Receiving SCCP messages
+4. Sending SCCP messages
+
+
+1. SCCP inside the IPA header
+
+Many Soft-MSCs implement something that is called SCCP/lite. This means
+that SCCP messages are transported inside a small multiplexing protocol
+over TCP/IP. This is an alternative to a full SIGTRAN implementation.
+
+The multiplexing protocol is the same as used with the sysmoBTS and the
+ip.access nanoBTS. It is a three byte header with two bytes for the length
+in network byte order and one byte for the type. The type to be used for
+SCCP is 0xFD.
+
+ struct ipa_header {
+ uint16_t length_in_network_order;
+ uint8_t type;
+ } __attribute__((packed));
+
+
+
+2. Supported SCCP message types
+
+To implement GSM 08.08 only a subset of SCCP messages need to be implemented.
+For transporting paging and reset messages SCCP UDT messages are used. For
+the connections with a Mobile Station (MS) a SCCP connection is opened. This
+means that the SCCP CR, SCCP CC, SCCP CREF, SCCP RLC, SCCP RLSD, SCCP DT1
+and SCCP IT messages are supported.
+
+
+3. Receiving SCCP UDT messages
+
+This is an illustration of the flow of messages. The IPA multiplexing protocol
+is used for various protocols. This means there is a central place where the
+multiplexing stream terminates. The stream is terminated in the osmo_bsc_msc.c
+file and the ipaccess_a_fd_cb method. For SCCP messages the SCCP dispatching
+sccp_system_incoming method is called. This function is implemented in the
+libosmo-sccp library.
+
+To receive UDT messages osmo_bsc_sccp.c:osmo_bsc_sccp_init is using the
+sccp_set_read function to register a callback for UDT messages. The callback
+is msc_sccp_read and it is calling bsc_handle_udt that is implemented in the
+osmo_bsc_bssap.c. This function will handle the GSM 08.08 BSSAP messages.
+Currently only the reset acknowledge and the paging messages are handled.
+
+The BSC currently does not accept incoming SCCP messages and is only opening
+SCCP connections to the MSC. When opening a connection the callbacks for state
+changes (connection confirmed, released, release complete) are set and a routine
+for handling incoming data. This registration is done in the osmo_bsc_sccp.c
+file and the bsc_create_new_connection method. The name of the callback is
+msc_outgoing_sccp_data and this will call bsc_handle_dt1 that is implemented
+in the osmo_bsc_bssap.c file. This will forward the messages to the right
+Mobile Station (MS).
+
+
+4. Sending SCCP messages
+
+There are three parts to sending that will be explained below. The first part
+is to send an entire SCCP frame (which includes the GSM 08.08 data) to the
+MSC. This is done by first registering the low level sending. sccp_system_init
+is called with the function that is responsible for sending a message. The
+msc_sccp_write_ipa will call the msc_queue_write function with the data and
+the right MSC connection. Below the msc_queue_write the IPA header will be
+prepended to the msg and then send to the MSC.
+
+The BSC supports multiple different A-link connections, the decision to pick
+the right MSC is done in this method. It is either done via the SCCP connection
+or the ctx pointer.
+
+When the BSC is starting a BSS RESET message will be sent to the MSC. The reset
+is created in osmo_bsc_msc.c:initialize_if_needed and sccp_write is called with
+the GSM 08.08 data and the connection to use. The libosmo-sccp library will
+embed it into a SCCP UDT message and call the msc_sccp_write_ipa method.
+
+When a new SCCP connection is to be created the bsc_create_new_connection
+in the osmo_bsc_sccp.c file. The sccp_connection_socket method will create
+the context for a SCCP connection. The state and data callback will be used
+to be notified about data and changes. Once the connection is configured the
+bsc_open_connection will be called that will ask the libosmo-sccp library to
+create a SCCP CR message using the sccp_connection_connect method. For active
+connections the sccp_connection_write method will be called.
+
+
+
diff --git a/doc/oml-interface.txt b/doc/oml-interface.txt
new file mode 100644
index 000000000..02bead77a
--- /dev/null
+++ b/doc/oml-interface.txt
@@ -0,0 +1,22 @@
+oml interface design notes
+
+problems:
+
+* there is no way how to tag a command sent to the BTS, with the response
+ having the same tag to identify the originator of the command
+* therefore, we can have e.g. both the BSC and the OML interface send a
+ SET ATTRIBUTE message, where the responses would end up at the wrong
+ query.
+* The BTS has 10s to ACK/NACK a command. We do not run any timers.
+
+the only possible solutions i can imagine:
+* have some kind of exclusive locking, where the OML interface gets blocked
+ from the BSC and is exclusively assigned to the OML console until all commands
+ of the OML console have terminated. This can either be done explicitly
+ dynamically or on demand
+
+* use the OML interface synchronously, i.e. always wait for the response from
+ the BTS before
+
+* unilateral / unsolicited messages need to be broadcasted to both the BSC and
+ the OML console
diff --git a/doc/osmo-nitb-data_structures.dot b/doc/osmo-nitb-data_structures.dot
new file mode 100644
index 000000000..81955e8b9
--- /dev/null
+++ b/doc/osmo-nitb-data_structures.dot
@@ -0,0 +1,33 @@
+digraph G {
+ net [label="gsm_network"]
+ bts [label="gsm_bts"]
+ trx [label="gsm_bts_trx"]
+ ts [label="gsm_bts_trx_ts"]
+ lchan [label="gsm_lchan"]
+ sub [label="gsm_subscriber"]
+ subcon [label="gsm_subscriber_conn"]
+ sccpcon [label="osmo_bsc_sccp_con"]
+ subgrp [label="gsm_subscriber_group"]
+
+ net -> bts
+ bts -> trx
+ trx -> ts
+ ts -> lchan
+
+ lchan -> ts
+ ts -> trx
+ trx -> bts
+ bts -> net
+
+ lchan -> subcon
+
+ subcon -> sub
+ subcon -> sccpcon
+ subcon -> lchan
+ subcon -> lchan [label="ho_lchan"]
+ subcon -> bts
+ subcon -> lchan [label="secondary_lchan"]
+
+ sub -> subgrp
+ subgrp -> net
+}
diff --git a/doc/paging.txt b/doc/paging.txt
new file mode 100644
index 000000000..c597c22b4
--- /dev/null
+++ b/doc/paging.txt
@@ -0,0 +1,48 @@
+
+GSM Paging implementation in OpenBSC
+
+== Code structure ==
+
+The code is implemented in the libbsc/paging.c file. The external
+interface is documented/specified in the include/openbsc/paging.h
+header file. The code is used by the NITB and BSC application.
+
+
+== Implementation ==
+
+Paging can be initiated in two ways. The standard way is to page by
+LAC. Each BTS has its own list/queue of outstanding paging operation.
+When a subscriber is paged one "struct paging_request" per BTS will
+be allocated and added to the tail of the list. The BTS is supposed
+to be configured to not repeat the paging.
+
+A paging_request will remain in the queue until a paging response or at
+the expiry of the T3113. Every 500 milliseconds a RSL paging command is
+send to the BTS. The 500 milliseconds is a throttling to not crash the
+ip.access nanoBTS. Once one paging_request has been handled it will be
+put at the end of the queue/list and the available slots for the BTS
+will be decreased.
+
+The available slots will be updated based on the paging load information
+element of the CCCH Load indication. If no paging slots are considered
+to be available and no load indication is sent a timer is started. The
+current timeout is 500 milliseconds and at the expiry of the timer the
+available slots will be set to 20.
+
+OpenBSC has the " paging free <-1-1024>" configuration option. In case
+there are less free channels than required no paging request will be
+sent to the BTS. Instead it will be attempted to send the paging request
+at the next timeout (500 milliseconds).
+
+== Limitation ==
+
+The paging throughput could be higher but this has lead to crashes on the
+ip.access nanoBTS in the past.
+
+== Configuration ==
+
+=== ip.access nanoBTS ===
+
+The current CCCH Load indication threshold is 10% and the period is 1 second.
+The code can be found inside the src/libbsc/bts_ipaccess_nanobts.c inside the
+nanobts_attr_bts array.