diff --git a/src/osmo_gsm_tester/obj/hss_open5gs.py b/src/osmo_gsm_tester/obj/hss_open5gs.py
new file mode 100644
index 0000000..211d09a
--- /dev/null
+++ b/src/osmo_gsm_tester/obj/hss_open5gs.py
@@ -0,0 +1,158 @@
+# osmo_gsm_tester: specifics for running an Open5GS hssd process
+#
+# Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH
+#
+# Author: Pau Espin Pedrol <pespin@sysmocom.de>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+import pprint
+
+from ..core import log, util, config, template, process, remote
+from ..core import schema
+from . import epc
+
+def on_register_schemas():
+    pass
+
+class Open5gsHSS(log.Origin):
+
+    REMOTE_DIR = '/osmo-gsm-tester-open5gs'
+    BINFILE = 'open5gs-hssd'
+    CFGFILE = 'open5gs-hssd.yaml'
+    LOGFILE = 'open5gs-hssd.log'
+    DIAMETERFILE = 'open5gs-freediameter.conf'
+
+    def __init__(self, testenv, o5gs_epc):
+        super().__init__(log.C_RUN, 'open5gs-hssd')
+        self.testenv = testenv
+        self.o5gs_epc = o5gs_epc
+        self._run_node = o5gs_epc.run_node()
+        self.run_dir = None
+        self.config_file = None
+        self.log_file = None
+        self.diameter_file = None
+        self.process = None
+        self.rem_host = None
+        self.remote_inst = None
+        self.remote_config_file = None
+        self.remote_log_file = None
+        self.remote_diameter_file = None
+
+    def cleanup(self):
+        if self.process is None:
+            return
+        if self._run_node.is_local():
+            return
+        # copy back files (may not exist, for instance if there was an early error of process):
+        try:
+            self.rem_host.scpfrom('scp-back-log', self.remote_log_file, self.log_file)
+        except Exception as e:
+            self.log(repr(e))
+
+    def start(self):
+        self.log('Starting %s' % Open5gsHSS.BINFILE)
+        if self._run_node.is_local():
+            self.start_locally()
+        else:
+            self.start_remotely()
+
+    def start_remotely(self):
+        remote_env = { 'LD_LIBRARY_PATH': self.remote_inst.child('lib') }
+        remote_lib = self.remote_inst.child('lib')
+        remote_binary = self.remote_inst.child('bin', Open5gsHSS.BINFILE)
+
+        args = (remote_binary, '-c', self.remote_config_file)
+
+        self.process = self.rem_host.RemoteProcess(Open5gsHSS.BINFILE, args, remote_env=remote_env)
+        self.testenv.remember_to_stop(self.process)
+        self.process.launch()
+
+    def start_locally(self):
+        binary = self.inst.child('bin', Open5gsHSS.BINFILE)
+        lib = self.inst.child('lib')
+        env = { 'LD_LIBRARY_PATH': util.prepend_library_path(lib) }
+
+        args = (binary, '-c', os.path.abspath(self.config_file))
+
+        self.process = process.Process(self.name(), self.run_dir, args, env=env)
+        self.testenv.remember_to_stop(self.process)
+        self.process.launch()
+
+    def configure(self, values):
+        self.run_dir = util.Dir(self.o5gs_epc.run_dir.new_dir(self.name()))
+        self.inst = util.Dir(os.path.abspath(self.testenv.suite().trial().get_inst('open5gs', self._run_node.run_label())))
+        if not os.path.isdir(self.inst.child('lib')):
+            raise log.Error('No lib/ in', self.inst)
+        if not self.inst.isfile('bin', Open5gsHSS.BINFILE):
+            raise log.Error('No %s binary in' % Open5gsHSS.BINFILE, self.inst)
+
+        self.config_file = self.run_dir.child(Open5gsHSS.CFGFILE)
+        self.log_file = self.run_dir.child(Open5gsHSS.LOGFILE)
+        self.diameter_file = self.run_dir.child(Open5gsHSS.DIAMETERFILE)
+
+        if not self._run_node.is_local():
+            self.rem_host = remote.RemoteHost(self.run_dir, self._run_node.ssh_user(), self._run_node.ssh_addr())
+            remote_prefix_dir = util.Dir(Open5gsHSS.REMOTE_DIR)
+            self.remote_inst = util.Dir(remote_prefix_dir.child(os.path.basename(str(self.inst))))
+            remote_run_dir = util.Dir(remote_prefix_dir.child(Open5gsHSS.BINFILE))
+
+            self.remote_config_file = remote_run_dir.child(Open5gsHSS.CFGFILE)
+            self.remote_log_file = remote_run_dir.child(Open5gsHSS.LOGFILE)
+            self.remote_diameter_file = remote_run_dir.child(Open5gsHSS.DIAMETERFILE)
+
+        logfile = self.log_file if self._run_node.is_local() else self.remote_log_file
+        diameter_file = self.diameter_file if self._run_node.is_local() else self.remote_diameter_file
+        inst_prefix = str(self.inst) if self._run_node.is_local() else str(self.remote_inst)
+        config.overlay(values, dict(hss=dict(log_filename=logfile,
+                                             diameter_filename=diameter_file,
+                                             inst_prefix=inst_prefix)))
+        config.overlay(values, dict(diameter=dict(identity=self.diameter_name(),
+                                                  inst_prefix=inst_prefix,
+                                                  listen_address=self.o5gs_epc.addr(),
+                                                  listen_port=self.diameter_port(),
+                                                  connect_name=self.o5gs_epc.mme.diameter_name(),
+                                                  connect_address=self.o5gs_epc.addr(),
+                                                  connect_port=self.o5gs_epc.mme.diameter_port())))
+
+        self.dbg('OPEN5GS-HSS CONFIG:\n' + pprint.pformat(values))
+
+        with open(self.config_file, 'w') as f:
+            r = template.render(Open5gsHSS.CFGFILE, values)
+            self.dbg(r)
+            f.write(r)
+
+        with open(self.diameter_file, 'w') as f:
+            r = template.render(Open5gsHSS.DIAMETERFILE, values)
+            self.dbg(r)
+            f.write(r)
+
+        if not self._run_node.is_local():
+            self.rem_host.recreate_remote_dir(self.remote_inst)
+            self.rem_host.scp('scp-inst-to-remote', str(self.inst), remote_prefix_dir)
+            self.rem_host.recreate_remote_dir(remote_run_dir)
+            self.rem_host.scp('scp-cfg-to-remote', self.config_file, self.remote_config_file)
+            self.rem_host.scp('scp-diam-to-remote', self.diameter_file, self.remote_diameter_file)
+
+    def running(self):
+        return not self.process.terminated()
+
+    def diameter_name(self):
+        return 'hss'
+
+    def diameter_port(self):
+        return 3868;
+
+# vim: expandtab tabstop=4 shiftwidth=4