Osmocom TTCN-3 Test Suites

developed in 2017+2018
compiled using Eclipse TITAN
- uses just a command-line compiler + Makefiles
- no IDE needed at all, don’t let Eclipse fool you
containerized in Docker
executed by Jenkins CI

Terminology

ATS: Abstract Test Suite
MTC: Main Test Component
PTC: Parallel Test Component
IUT: Implementation Under Test

Test Suite Philosophy

test one network element (our IUT)
test external behavior (3GPP and non-3GPP)
emulate entire environment from TTCN-3
don’t reuse Osmocom C-code protocol implementations in the tests
test against independent TTCN-3 implementations!

What to test?

successful cases
erroneous cases (no answer, NACK, …)
- many difficult to reproduce with real phones/devices
load / resource exhaustion
spec compliance
focus on functionality actually relevant to IUT

Why TTCN-3 + TITAN

TTCN-3 specifically designed for telecom protocol testing
TITAN team released many telecom protocols in TTCN-3, such as
- BSSAP, L3 (RR/MM/CC), SMS (CP/RP/TP), SS, M3UA, SCCP, GTP, NS, BSSGP, …
- shortens our test development cycle
- permits us to test against known working industry implementations

Test suites for Osmocom CNI components

osmo-bts
osmo-bsc
osmo-msc
osmo-mgw
osmo-hlr
osmo-sip-connector
osmo-sgsn
osmo-ggsn

Test suites in progress

osmo-pcu
osmo-bsc_nat

BTS_Tests.ttcn

external interfaces
- A-bis side: RSL (emulates BSC-side server)
- Um side: L1CTL to control MS
- PCU side: pcu_socket

BSC_Tests.ttcn

external interfaces
- A-bis side: RSL (emulates BTS-side client)
- A-side: BSSAP/SCCP/M3UA (emulates MSC-side)
- MGW side: MGCP (emulates MGW side)

MSC_Tests.ttcn

external interfaces
- A: BSSAP/SCCP/M3UA (emulates BSC-side)
- MNCC: MNCC/unix-domain (emulates ext. MNCC side)
- MGW: MGCP (emulates MGW side)
- GSUP (impllements HLR side)

MGCP_Test.ttcn

external interfaces
- MGCP (emulates call agent)
- RTP (stream source/sink)

HLR_Tests.ttcn

external interfaces
- GSUP (emulates VLR/SGSN side)

SIP_Tests.ttcn

external interfaces
- MNCC (emulates MSC side)
- SIP (emulates SIP switch)

SGSN_Tests.ttcn

external interfaces
- Gb (emulates PCU side NS/BSSGP + MS)
- GSUP (emulates HLR)

GGSN_Tests.ttcn

external interfaces
- Gp: GTP (emulates SGSN)
- Gi: IP (emulates Internet)

Dockerized Setup

one process per container
packages either
- IUT (e.g. osmo-bsc)
- ATS (compiled docker test suite)
- other utility (e.g. trxcon or osmo-bts-omldummy)
why?
- no need for local ip/network configuration
- standardized / packaged setup on every machine
- run older/newer versions of ATS against older/newer IUT

Jenkins CI Execution

update docker-playground.git
1. contains Dockerfile for ATS + IUT
rebuild IUT container[s] (e.g. osmo-bts-master)
1. git magic ensures re-build only if osmo-bts.git master changed
rebuild ATS container (e.g. ttcn3-bts-test)
1. git magic ensures re-build only if osmo-ttcn3-hacks.git master changed
run docker-playground/ttcn3-bts-test/jenkins.sh
1. creates docker network
2. starts IUT + ATS docker containers
3. collects test results

Jenkins CI Reporting

junit-xml generation
store artefacts
- pcap file of every test case
- ATS log file (TTCN-3 testsuite)
- IUT log file[s] (osmo-*.log)
- IUT config file[s] (osmo-*.cfg)
see https://jenkins.osmocom.org/jenkins/view/TTCN3/

Further Reading

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