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Diffstat (limited to 'openbsc/doc/call-routing.txt')
-rw-r--r-- | openbsc/doc/call-routing.txt | 25 |
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 |