manual: add "Configuring Primary Links" and "Multiple instances"
Change-Id: I0919392b716e2812ff19d7efa5d1ba535b08eb91
diff --git a/doc/manuals/chapters/running.adoc b/doc/manuals/chapters/running.adoc
index 41909e2..57b8231 100644
--- a/doc/manuals/chapters/running.adoc
+++ b/doc/manuals/chapters/running.adoc
@@ -35,3 +35,83 @@
Set the global log level for logging to stderr. This has mostly
been deprecated by VTY based logging configuration, see
<<logging>> for more information.
+
+
+=== Multiple instances
+
+Running multiple instances of `osmo-hnbgw` on the same computer is possible if
+all interfaces (VTY, CTRL, Iuh) are separated using the appropriate
+configuration options. The IP based interfaces are binding to local host by
+default. In order to separate the processes, the user has to bind those
+services to specific but different IP addresses and/or ports.
+
+The VTY and the Control interface can be bound to IP addresses from the loopback
+address range, for example:
+
+----
+line vty
+ bind 127.0.0.2
+ctrl
+ bind 127.0.0.2
+----
+
+The Iuh interface can be bound to an individual port:
+
+----
+hnbgw
+ iuh
+ local-ip 0.0.0.0
+ local-port 29169
+----
+
+For the following links, OsmoHNBGW acts as a client and does not listen/bind to a
+specific interface, and will hence not encounter conflicts for multiple instances
+running on the same interface:
+
+- The SCCP/M3UA links are established by OsmoHNBGW contacting an STP.
+
+To run multiple OsmoHNBGW instances on the same SCCP routing, each HNBGW has to
+configure a distinct point-code, see <<configure_iucs_iups>>.
+
+
+=== Configuring Primary Links
+
+[[configure_iucs_iups]]
+==== Configure SCCP/M3UA to connect to an MSC's _IuCS_ and an SGSN's _IuPS_ interface
+
+OsmoHNBGW acts as client to contact an STP instance and establish an SCCP/M3UA
+link.
+
+An example configuration of OsmoHNBGW's SCCP link:
+
+----
+cs7 instance 0
+ point-code 0.23.5
+ asp asp-clnt-OsmoHNBGW 2905 0 m3ua
+ remote-ip 127.0.0.1
+ sctp-role client
+ sccp-address msc
+ routing-indicator PC
+ point-code 0.23.1
+ sccp-address sgsn
+ routing-indicator PC
+ point-code 0.23.2
+hnbgw
+ iucs
+ remote-addr msc
+ iups
+ remote-addr sgsn
+----
+
+==== Configure RUA to accept Iuh connections from hNodeB
+
+OsmoHNBGW acts as server to accept Iuh connections from hNodeB devices.
+
+An example configuration for OsmoHNBGW's RUA server:
+
+----
+hnbgw
+ iuh
+ local-ip 10.9.8.7
+ local-port 29169
+----