diff --git a/.gitignore b/.gitignore
index 2e88651..406a33b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,7 @@ ttcn3/out/
 ttcn3/make/
 ttcn3/.run.sh
 ttcn3/usr_local
+ttcn3/var_local
 current_log
 lastlog
 autolog
diff --git a/gen_makefile.py b/gen_makefile.py
index d306364..3f6a994 100755
--- a/gen_makefile.py
+++ b/gen_makefile.py
@@ -364,7 +364,7 @@ def gen_make(proj, deps, configure_opts, jobs, make_dir, src_dir, build_dir, url
   deps_installed = ' '.join(['.make.%s.install' % d for d in deps])
   deps_reinstall = ' '.join(['%s-reinstall' %d for d in deps])
   cflags = 'CFLAGS=-g ' if args.build_debug else ''
-  docker_cmd = f'{args.docker_cmd} ' if args.docker_cmd else ''
+  docker_cmd = f'OSMODEV_PROJECT={proj} {args.docker_cmd} ' if args.docker_cmd else ''
   check = 'check' if make_check else ''
   no_ldconfig = '#' if no_ldconfig else ''
   sudo_ldconfig = '' if ldconfig_without_sudo else 'sudo '
diff --git a/ttcn3/scripts/docker_configure_make.sh b/ttcn3/scripts/docker_configure_make.sh
index 7a79ff1..e6857fd 100755
--- a/ttcn3/scripts/docker_configure_make.sh
+++ b/ttcn3/scripts/docker_configure_make.sh
@@ -4,16 +4,60 @@
 # location inside the docker container. A usr_local dir is mounted to
 # /usr/local, so 'make install' can put all files there and following builds
 # have the files available.
+# env vars: OSMODEV_PROJECT
 DIR_OSMODEV="$(readlink -f "$(dirname $0)/../..")"
 DIR_MAKE="$DIR_OSMODEV/ttcn3/make"
 DIR_USR_LOCAL="$DIR_OSMODEV/ttcn3/usr_local"
+DIR_VAR_LOCAL="$DIR_OSMODEV/ttcn3/var_local"
 DIR_CCACHE="$DIR_OSMODEV/ttcn3/ccache/osmocom-programs"
 RUN_SCRIPT="$DIR_OSMODEV/ttcn3/.run.sh"
-DOCKER_IMG="$1"
 UID="$(id -u)"
-shift
 
-mkdir -p "$DIR_MAKE" "$DIR_CCACHE"
+# Osmocom libraries and programs relevant for the current testsuite will be
+# built in this container. It must have all build dependencies available and
+# be based on the same distribution that master-* containers are based on, so
+# there are no incompatibilities with shared libraries.
+DOCKER_IMG_BUILD="debian-bookworm-build"
+DOCKER_IMG_BUILD_OGS="open5gs-master"
+
+docker_image_exists() {
+	test -n "$(docker images -q "$1")"
+}
+
+build_docker_img() {
+	local img="$1"
+	local dp="${DIR_OSMODEV}/src/docker-playground"
+
+	if ! docker_image_exists "$USER/$img"; then
+		echo "Building docker image: $USER/$img"
+		make -C "$dp/$img"
+	fi
+}
+
+build_docker_imgs() {
+	build_docker_img "$DOCKER_IMG_BUILD"
+
+	if [ "$OSMODEV_PROJECT" = "open5gs" ]; then
+		build_docker_img "$DOCKER_IMG_BUILD_OGS"
+	fi
+}
+
+set_docker_img_var() {
+	case "$OSMODEV_PROJECT" in
+	open5gs)
+		DOCKER_IMG="$USER/$DOCKER_IMG_BUILD_OGS"
+		;;
+	*)
+		DOCKER_IMG="$USER/$DOCKER_IMG_BUILD"
+		;;
+	esac
+}
+
+mkdir -p \
+	"$DIR_MAKE" \
+	"$DIR_CCACHE" \
+	"$DIR_USR_LOCAL" \
+	"$DIR_VAR_LOCAL"
 
 # Script running as user inside docker
 echo "#!/bin/sh -ex" > "$RUN_SCRIPT"
@@ -24,12 +68,16 @@ done
 echo >> "$RUN_SCRIPT"
 chmod +x "$RUN_SCRIPT"
 
+build_docker_imgs
+set_docker_img_var
+
 docker run \
 	--rm \
 	-t \
 	-e "LD_LIBRARY_PATH=/usr/local/lib" \
 	-v "$DIR_OSMODEV:$DIR_OSMODEV" \
 	-v "$DIR_USR_LOCAL:/usr/local" \
+	-v "$DIR_VAR_LOCAL:/var/local" \
 	-v "$RUN_SCRIPT:/tmp/run.sh:ro" \
 	-v "$DIR_CCACHE:/home/build/.ccache" \
 	"$DOCKER_IMG" \
diff --git a/ttcn3/ttcn3.sh b/ttcn3/ttcn3.sh
index 3426e7b..5c3fae6 100755
--- a/ttcn3/ttcn3.sh
+++ b/ttcn3/ttcn3.sh
@@ -5,16 +5,11 @@ DIR_OSMODEV="$(readlink -f "$(dirname $0)/..")"
 DIR_MAKE="${DIR_MAKE:-${DIR_OSMODEV}/ttcn3/make}"
 DIR_OUTPUT="${DIR_OUTPUT:-${DIR_OSMODEV}/ttcn3/out}"
 DIR_USR_LOCAL="$DIR_OSMODEV/ttcn3/usr_local"
+DIR_VAR_LOCAL="$DIR_OSMODEV/ttcn3/var_local"
 JOBS="$(nproc)"
 KERNEL_DIR=""
 KERNEL_SKIP_MARKER="$DIR_MAKE/.kernel_built_from_source"
 ARG_TEST_NAME=""
-
-# Osmocom libraries and programs relevant for the current testsuite will be
-# built in this container. It must have all build dependencies available and
-# be based on the same distribution that master-* containers are based on, so
-# there are no incompatibilities with shared libraries.
-DOCKER_IMG_BUILD="debian-bookworm-build"
 DOCKER_IMG_TITAN="debian-bookworm-titan"
 
 clean() {
@@ -29,7 +24,8 @@ clean() {
 	rm -rf \
 		"$DIR_MAKE" \
 		"$DIR_OUTPUT" \
-		"$DIR_USR_LOCAL"
+		"$DIR_USR_LOCAL" \
+		"$DIR_VAR_LOCAL"
 
 	if [ -d "$DIR_OSMODEV/src/osmo-ttcn3-hacks" ]; then
 		make -C "$DIR_OSMODEV/src/osmo-ttcn3-hacks" clean
@@ -98,6 +94,7 @@ parse_args() {
 			echo "  $name -d ggsn"
 			echo "  $name -k ggsn"
 			echo "  $name -k -f ggsn"
+			echo "  $name ggsn-ogs"
 			exit 1
 			;;
 		esac
@@ -134,7 +131,7 @@ get_testsuite_dir() {
 	case "$PROJECT" in
 		bsc-*) echo "$hacks/bsc" ;;
 		bts-*) echo "$hacks/bts" ;;
-		ggsn) echo "$hacks/ggsn_tests" ;;
+		ggsn|ggsn-ogs) echo "$hacks/ggsn_tests" ;;
 		pcu-sns) echo "$hacks/pcu" ;;
 		*) echo "$hacks/$PROJECT" ;;
 	esac
@@ -145,6 +142,7 @@ get_testsuite_config() {
 		bts-gprs) echo "BTS_Tests_GPRS.cfg" ;;
 		bts-oml) echo "BTS_Tests_OML.cfg" ;;
 		pcu-sns) echo "PCU_Tests_SNS.cfg" ;;
+		ggsn-ogs) echo "GGSN_Tests.cfg" ;;
 		*) echo "$(get_testsuite_name).cfg" ;;
 	esac
 }
@@ -156,6 +154,9 @@ get_testsuite_dir_docker() {
 		bsc-*)
 			echo "$dp/ttcn3-bsc-test-$(echo "$PROJECT" | cut -d - -f 2-)"
 			;;
+		ggsn-ogs)
+			echo "$dp/ttcn3-ggsn-test-ogs"
+			;;
 		*)
 			echo "$dp/ttcn3-$PROJECT-test"
 			;;
@@ -167,6 +168,9 @@ get_testsuite_image() {
 		bsc-*)
 			echo "$USER/ttcn3-bsc-test"
 			;;
+		ggsn-ogs)
+			echo "$USER/ttcn3-ggsn-test"
+			;;
 		*)
 			echo "$USER/ttcn3-$PROJECT-test"
 			;;
@@ -185,6 +189,7 @@ get_programs() {
 	case "$PROJECT" in
 		bsc|bsc-*) echo "osmo-stp osmo-bsc osmo-bts-omldummy" ;;
 		bts) echo "osmo-bsc osmo-bts-trx" ;;
+		ggsn-ogs) echo "open5gs" ;;
 		msc) echo "osmo-stp osmo-msc" ;;
 		pcu-sns) echo "osmo-pcu" ;;
 		pcu) echo "osmo-pcu osmo-bsc osmo-bts-virtual" ;;
@@ -218,7 +223,6 @@ setup_dir_make() {
 	cd "$DIR_OSMODEV"
 
 	local docker_cmd="$DIR_OSMODEV/ttcn3/scripts/docker_configure_make.sh"
-	docker_cmd="$docker_cmd $USER/$DOCKER_IMG_BUILD"
 
 	./gen_makefile.py \
 		default.opts \
@@ -294,17 +298,6 @@ prepare_local_bin() {
 	done
 }
 
-prepare_docker_build_container() {
-	local dp="${DIR_OSMODEV}/src/docker-playground"
-
-	if docker_image_exists "$USER/$DOCKER_IMG_BUILD"; then
-		return
-	fi
-
-	echo "Building docker image: $USER/$DOCKER_IMG_BUILD"
-	make -C "$dp/$DOCKER_IMG_BUILD"
-}
-
 prepare_docker_testsuite_container() {
 	local testsuite_image="$(get_testsuite_image)"
 
@@ -352,6 +345,12 @@ build_osmo_programs() {
 	set +x
 
 	for program in $programs; do
+		if [ "$program" = "open5gs" ]; then
+			# open5gs binaries have different names (open5gs-mmed,
+			# etc.)
+			continue
+		fi
+
 		local repo="$(get_program_repo "$program")"
 		local usr_local_bin="$DIR_USR_LOCAL/bin"
 
@@ -472,6 +471,7 @@ run_docker() {
 	DOCKER_ARGS="\
 		-e LD_LIBRARY_PATH=/usr/local/lib \
 		-v "$DIR_USR_LOCAL":/usr/local:ro \
+		-v "$DIR_VAR_LOCAL":/var/local:ro \
 		-v $hacks:/osmo-ttcn3-hacks:ro \
 		"
 	if [ -n "$ARG_TEST_NAME" ]; then
@@ -513,7 +513,6 @@ clone_repo "osmo-ttcn3-hacks"
 clone_repo "docker-playground"
 check_dir_testsuite
 prepare_local_bin
-prepare_docker_build_container
 build_extra_libraries
 build_osmo_programs
 build_kernel