diff options
authorNeels Hofmeyr <>2017-12-07 19:39:18 +0100
committerHarald Welte <>2017-12-07 22:30:42 +0000
commit7b06baccd60b0f02e4d7f8be29f8a24fc1764a06 (patch)
parentda63831ef9eca0afc32aa90e72001793ba3488e0 (diff)
common: bts: dyn ts: explain dyn_ts_allow_tch_f from OsmoBSC viewpoint
1 files changed, 14 insertions, 3 deletions
diff --git a/common/chapters/bts.adoc b/common/chapters/bts.adoc
index b8d9f1b..116b69d 100644
--- a/common/chapters/bts.adoc
+++ b/common/chapters/bts.adoc
@@ -317,9 +317,20 @@ messaging for `TCH/F_TCH/H_PDCH` timeslots is compatible with Ericsson RBS.
BTS models supporting this timeslot kind are shown in <<dyn_ts_compat>>.
-NOTE: At the time of writing, OsmoNITB disables TCH/F on this timeslot type due
-to transcoding limitations. Operation of OsmoBSC with a third-party MSC is not
-affected by this limitation. See
+In the lack of transcoding capabilities, this timeslot type may cause
+mismatching codecs to be selected for two parties of the same call, which would
+cause call routing to fail ("`Cannot patch through call with different channel
+types: local = TCH_F, remote = TCH_H`"). A workaround is to disable TCH/F on
+this timeslot type, i.e. to allow only TCH/H. To disable TCH/F on Osmocom
+style dynamic timeslots, use a configuration of
+ dyn_ts_allow_tch_f 0
+In OsmoNITB, disabling TCH/F on Osmocom dynamic timeslots is the default. In
+OsmoBSC, the default is to allow both.
==== ip.access Style Dynamic Timeslots (TCH/F_PDCH)