Osmocom Libraries » libosmo-abis

h1. libosmo-abis

{{>toc}}

h2. General description

This is a library containing common/shared code regarding the A-bis interface between BTS and BSC.

It implements drivers for mISDN and DAHDI based E1 cards, as well as some A-bis/IP dialects.

{{graphviz_link()

digraph G{

  //rankdir = LR;

  Application -> loa;

  loa -> mISDN;

  loa -> DAHDI;

  loa -> e1d;

  loa -> IPA;

  mISDN -> HW;

  DAHDI -> HW;

  e1d -> HW;

  IPA -> IP;

  e1d -> vpair;

  HW -> BTS;

  IP -> BTS;

  Application [label="Application\nosmo-nitb / osmo-bsc"];

  e1d [label="osmo-e1d"];

  loa [label="libosmo-abis\ne1_input"];

  IP [label="Abis/IP"];

  HW [label="E1 Hardware"];

  vpair [label="Virtual E1 pair"];

}

}}

h2. Preconditions 

To compile libosmo-abis you will need the following tools:

<pre>

sudo apt-get install build-essential libtool libortp-dev dahdi-source libsctp-dev shtool autoconf automake git-core pkg-config make gcc

</pre>

h2. Obtaining it

To obtain libosmo-abis, you can use the following git URL:

<pre>

git clone https://gitea.osmocom.org/osmocom/libosmo-abis.git

</pre>

h2. Compiling and installing it

To compile and install it as standalone:

<pre>

cd libosmo-abis/

autoreconf -i

./configure

make

sudo make install

sudo ldconfig -i

cd ..

</pre>

h2. Licensing

This library is GPL licensed. This means you *cannot use this library from non-GPL licensed code without infringing copyright!

h2. Browsing its source code

You can do that using our gitea installation at https://gitea.osmocom.org/osmocom/libosmo-abis

h2. Input Drivers

There are currently the following input drivers available:

h3. misdn

This input driver supports the mISDN code as it is present in mainline linux-2.6 kernels.

It uses the in-kernel LAPD implementation, and is thus bound to some restrictions.  Specifically,

you can only have one signalling timeslot (D-channel) in every E1 line, which may cause problems

with multi-BTS or multi-TRX setups (particularly in the case of Nokia A-bis)

You have to configure which E1 timeslot is to be used for signalling by module parameters, e.g.

<pre>

modprobe hfcmulti dslot=1

</pre>

will configure TS1 as signalling.

h3. misdn_lapd

This input driver supports the mISDN code as it is present in mainline linux-2.6 kernels.

However, unlike the "misdn" driver, it runs LAPD in userspace, as part of libosmo-abis.

In order to be able to use it, you will need to make sure the mISDN kernel driver does not

configure any timeslot to signalling, e.g.

<pre>

modprobe hfcmulti dslot=-1

</pre>

(notice the "-" in front of 1 to indicate "no signalling timeslot").

h3. dahdi

This driver supports the DAHDI (formerly known as zaptel) out-of-tree drivers for e.g.

the various Digium and Digium compatible E1/T1/J1 cards.

h3. ipa

This implements A-bis over IP, as implemented by ip.access nanoBTS as well as all BTSs running [[OsmoBTS:]].

h3. hsl

Experimental driver for support of the [HSL_Femto]

h3. e1d

This driver supports [[osmo-e1d:]], the software-defined E1 inplementation of Osmocom.

osmo-e1d in turn supports the Osmocom open hardware ICE40 FPGA core, as well as virtual E1 loops for testing ([[osmo-e1d:vpair]]).

*You must build with @./configure --enable-e1d@ to support this driver*

{{include(cellular-infrastructure:MacroCommercialSupport)}}