aboutsummaryrefslogtreecommitdiffstats
path: root/openbsc/doc/call-routing.txt
diff options
context:
space:
mode:
Diffstat (limited to 'openbsc/doc/call-routing.txt')
-rw-r--r--openbsc/doc/call-routing.txt25
1 files changed, 25 insertions, 0 deletions
diff --git a/openbsc/doc/call-routing.txt b/openbsc/doc/call-routing.txt
new file mode 100644
index 000000000..3402f9e33
--- /dev/null
+++ b/openbsc/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