running-osmo-gsm: Add MGW into the picture

4 files changed, 82 insertions, 0 deletions

diff --git a/2021/running_osmo_gsm-2021/osmo-mgw-bsc-msc.dot b/2021/running_osmo_gsm-2021/osmo-mgw-bsc-msc.dot
new file mode 100644
index 0000000..c954717
--- /dev/null
+++ b/2021/running_osmo_gsm-2021/osmo-mgw-bsc-msc.dot
@@ -0,0 +1,17 @@
+digraph G {
+    rankdir = LR;
+    BTS -> BSC [label="Abis"];
+    BSC -> OsmoMSC [label="3GPP AoIP"];
+    OsmoMSC -> OsmoMGW [label="MGCP"];
+    BSC -> OsmoMGW [label="RTP",dir=both];
+    OsmoMSC -> OsmoSIP [label="MNCC"];
+    OsmoSIP -> PBX [label="SIP Trunk"];
+    OsmoMGW -> PBX [label="RTP",dir=both];
+    {rank=same OsmoMSC OsmoMGW}
+    OsmoSIP [label="osmo-sip-connector"];
+    OsmoMGW [color=red];
+
+    hNodeB -> OsmoHNBGW [label="Iuh"];
+    OsmoHNBGW -> OsmoMSC [label="IuCS"];
+    hNodeB -> OsmoMGW [label="RTP",dir=both];
+}
diff --git a/2021/running_osmo_gsm-2021/osmo-mgw-bsc.dot b/2021/running_osmo_gsm-2021/osmo-mgw-bsc.dot
new file mode 100644
index 0000000..757ca7a
--- /dev/null
+++ b/2021/running_osmo_gsm-2021/osmo-mgw-bsc.dot
@@ -0,0 +1,10 @@
+digraph G {
+    rankdir = LR;
+    OsmoBTS -> OsmoBSC [label="Abis/IP"];
+    OsmoBSC -> OsmoMSC [label="3GPP AoIP"];
+    OsmoBSC -> OsmoMGW [label="MGCP"];
+    OsmoBTS -> OsmoMGW [label="RTP",dir=both];
+    OsmoMGW -> OsmoMSC [label="RTP",dir=both];
+    {rank=same OsmoBSC OsmoMGW}
+    OsmoMGW [color=red];
+}
diff --git a/2021/running_osmo_gsm-2021/running-osmo-gsm.adoc b/2021/running_osmo_gsm-2021/running-osmo-gsm.adoc
index a884d5b..a2da707 100644
--- a/2021/running_osmo_gsm-2021/running-osmo-gsm.adoc
+++ b/2021/running_osmo_gsm-2021/running-osmo-gsm.adoc
@@ -399,6 +399,24 @@ the home network, which has preference over others
 * interactive reference, tab-completion
 * `logging enable` adds log target to VTY session
 
+== osmo-mgw: User Plane
+
+* so far we've been looking at control plane (signalling) only
+* user plane (voice in most cases) is handled via RTP in IP based Osmocom CNI
+* control plane is separate from user plane
+* `osmo-mgw` acts as RTP proxy, both at BSC and at MSC level
+
+[graphviz]
+----
+include::osmo-mgw-bsc.dot[]
+----
+
+[graphviz]
+----
+include::osmo-mgw-bsc-msc.dot[]
+----
+
+
 == Further Reading
 
 User Manuals::
diff --git a/2021/running_osmo_gsm-2021/running-osmo-gsm.html b/2021/running_osmo_gsm-2021/running-osmo-gsm.html
index 31dd73e..53c3d74 100644
--- a/2021/running_osmo_gsm-2021/running-osmo-gsm.html
+++ b/2021/running_osmo_gsm-2021/running-osmo-gsm.html
@@ -4865,6 +4865,43 @@ interactive reference, tab-completion
 </div>

 </div>

 <div class="sect1 slide">

+<h1 id="_osmo_mgw_user_plane">osmo-mgw: User Plane</h1>

+<div class="sectionbody" style="max-width:45em">

+<ul class="">

+<li>

+<span>

+so far we&#8217;ve been looking at control plane (signalling) only

+</span>

+</li>

+<li>

+<span>

+user plane (voice in most cases) is handled via RTP in IP based Osmocom CNI

+</span>

+</li>

+<li>

+<span>

+control plane is separate from user plane

+</span>

+</li>

+<li>

+<span>

+<code>osmo-mgw</code> acts as RTP proxy, both at BSC and at MSC level

+</span>

+</li>

+</ul>

+<div class="imageblock graphviz">

+<div class="content">

+<img src="running-osmo-gsm__8.png" alt="running-osmo-gsm__8.png" />

+</div>

+</div>

+<div class="imageblock graphviz">

+<div class="content">

+<img src="running-osmo-gsm__9.png" alt="running-osmo-gsm__9.png" />

+</div>

+</div>

+</div>

+</div>

+<div class="sect1 slide">

 <h1 id="_further_reading">Further Reading</h1>

 <div class="sectionbody" style="max-width:45em">

 <div class="dlist"><dl class="">