rewrite README

Change-Id: I2487ddbd37f989eb29b45bbf07beb5be468b867d

README

@@ -1,39 +1,26 @@
-About OpenBSC
+About OsmoBSC
 =============
 
-OpenBSC started as a minimalistic all-in-one implementation of the GSM Network,
-with particular emphasis on the functionality typically provided by the BSC,
-MSC, HLR, VLR and SMSC.  Today it is a growing suite of libraries and programs,
-implementing protocol stacks and functional elements, including
+OsmoBSC originated from the OpenBSC project, which started as a minimalistic
+all-in-one implementation of the GSM Network. In 2017, OpenBSC had reached
+maturity and diversity (including M3UA SIGTRAN and 3G support in the form of
+IuCS and IuPS interfaces) that naturally lead to a separation of the all-in-one
+approach to fully independent separate programs as in typical GSM networks.
 
- * OsmoBSC - a pure GSM BSC, speaking Abis/IP to the BTS and A/IP to the MSC
- * OsmoBSC-MGCP - MGCP helper to the OsmoBSC software
- * OsmoNITB - a BSC+MSC+VLR+HLR+SMSC "Network in the box".
- * OsmoMSC - a voice CN with A/IP and IuCS/IP towards the BSC and/or HNB-GW
- * OsmoSGSN - a GPRS SGSN with Gb/IP and IuPS/IP towards the PCU and/or HNB-GW
- * Osmo-GbProxy - a Proxy to aggregate many Gb links as one Gb link to the SGSN
- * OsmoBSCNAT - a gateway aggregating many A links as one A link to the MSC
- * OsmoGTPHUB - a hub aggregating many GTP links (between SGSN and GGSN)
- * ipaccess-utils - some tools to discover + configure ip.access nanoBTS
- * bs11_config - a tool to configure the Siemens BS-11 microBTS
+OsmoBSC was one of the parts split off from the old openbsc.git. Before, it
+worked as a standalone osmo-bsc binary as well as a combination of libbsc and
+libmsc, i.e. the old OsmoNITB. Since the standalone OsmoMSC with a true A
+interface (and IuCS for 3G support) is available, OsmoBSC exists only as a
+separate standalone entity.
 
-Various interfaces towards the BTS are supported, among which are:
+OsmoBSC exposes
+- A over IP towards an MSC (e.g. OsmoMSC);
+- Abis interfaces towards various kinds of BTS;
+- The Osmocom typical telnet VTY and CTRL interfaces.
 
- * Classic A-bis over E1 using a mISDN based E1 interface. In other
-   words, you can connect existing GSM Base Transceiver Station (BTS)
-   through E1 to OpenBSC.  So far, we have made it work with the Siemens BS-11,
-   various Ericsson RBS2xxx BTS models and the Nokia MetroSite.
+Find OsmoBSC issue tracker and wiki online at
+https://osmocom.org/projects/osmobsc
+https://osmocom.org/projects/osmobsc/wiki
 
- * A-bis over IP as used by the ip.access nanoBTS product family as well as
-   the Open Source OsmoBTS software (by the same authors as OpenBSC).  OsmoBTS
-   in turn supports various transceiver hardware, including the sysmoBTS
-   product family, as well as SDR transceivers supported by OsmoTRX, such as
-   the UmTRX or USRP boardss.
-
- * IuCS and IuPS over IP towards an HNB-GW (see osmo-iuh) for UMTS (3G)
-   voice and data links.
-
-Find OpenBSC online at
-http://openbsc.osmocom.org/
-
-	Harald Welte <laforge@gnumonks.org>
+OsmoBSC-NAT is a specialized solution to navigating RTP streams through a NAT.
+(Todo: describe in more detail)