gprs: Honor GSM 04.64 8.4.2 Receipt of unacknowledged information
GSM 04.64 8.4.2 asks to ignore UI frames if the DLCI is not known,
or if the "(V(UR)- 32) <= N(U) < V(UR)". E.g. if we want to have
V(UR) == 511 and this frame is dropped, we would ignore N(U)'s
0 to 510. Calculate the delta.
The code is based on Jonathan Santos's "LLC UI window" fix but the
issue was discovered independly.
diff --git a/openbsc/tests/Makefile.am b/openbsc/tests/Makefile.am
index 64667c9..73e8b89 100644
--- a/openbsc/tests/Makefile.am
+++ b/openbsc/tests/Makefile.am
@@ -1,4 +1,4 @@
-SUBDIRS = debug gsm0408 db channel mgcp
+SUBDIRS = debug gsm0408 db channel mgcp gprs
if BUILD_NAT
SUBDIRS += bsc-nat