Miscellaneous Projects » Core testing infrastructure » osmo-uecups

h1. osmo-uecups

*osmo-uecups* (for _UE Control/User Plane Separation_) is a special-purpose project which emulates the UE/MME/SGW/SGSN side of GTP tunnels.  This can be used in a variety of test use cases where a P-GW or GGSN (or GTP roaming hub) should be tested with a variety of GTP sessions/tunnels/bearers.

This project is currently under development, hence there's no documentation yet.

An initial announcment can be found in the Eclipse TITAN Forum at https://www.eclipse.org/forums/index.php/t/1103391/

h2. Usage in PGW testing

The diagram below illustrates how the @osmo-uecups-daemon@ is used in testing of a PGW:

{{graphviz_link()

digraph G {

  rankdir=LR;

  ATS [label="Test Suite"];

  PGW [label="PGW (under test)"];

  daemon [label="osmo-uecups-daemon",color="red"];

  ATS -> PGW [label="GTP2C"];

  ATS -> daemon [label="UECUPS/SCTP"];

  daemon -> PGW [label="GTP1U"];

  PGW -> Internet [label="Gi"];

  subgraph cluster_foo {

    label="netns";

    program [label="program\n(e.g. ping)"];

  }

  program -> daemon [label="IP"];

}

}}

h3. osmo-uecups-daemon

@osmo-uecups-daemon@ has the following functionality

* receives instructions from the Test Suite via a JSON based "UECUPS" protcol

** *create_tun* creates a tunnel and an associaed network namespace with tun device inside

** *destroy_tun* destroys a previously created tunnel

** *start_program* executes a specified command/program within the network namespace of the tunnel

** *reset_all_state* deletes all tunnels, tun devices, network namespaces and kills all started programs

* encapsulates packets arriving on the tun devices into GTP1U and sends them to the PGW

* decapsulates GTP1u received from the PGW and passses them via the respective tun device [in the respective netns]

h3. TTCN3 integration

There are the following TTCN3 modules for integration into TTCN3 test suites, specifically using Eclipse TITAN:

* *UECUPS_Types.ttcn* contains abstract types used for the UECUPS protocol with the daemon (encoding/decoding of JSON performed automatically/implicitly by TITAN)

* *UECUPS_CodecPort.ttcn* contains the definition of a transcoding port on top of the IPL4asp_PT (SCTP)

** *UECUPS_CodecPort_CtrlFunct.ttcn* and *UECUPS_CodecPort_CtrlFunctDef.cc* are related helpers

For an example using all of the above, see the code in 

http://git.osmocom.org/osmo-ttcn3-hacks/tree/pgw/PGW_Tests.ttcn

h2. Source Code

Source code can be found in git at https://git.osmocom.org/osmo-uecups/