Cellular Network Infrastructure

Context¶

TITAN did not support ASN.1 PER until recently, so we worked this around by encoding/decoding to/from BER first, and then using proprietary libfftranscode to convert to/from PER.

https://gerrit.osmocom.org/c/osmo-ttcn3-hacks/+/13652

commit a013e68fc9024ce680f43e6fe53a3e9efb1cd42e
Author: Harald Welte <laforge@gnumonks.org>
Date:   Mon Jun 18 19:49:39 2018 +0200

    HNBAP, RUA and RANAP protocol codecs

    This patch introduces protocol codecs for the HNBAP, RUA and RANAP
    protocols, which is mandatory for testing IuCS, IuPS or Iuh in
    the future.

    As Eclipse TITAN ASN.1 only supports the BER codec and the above
    protocols all use APER, we need to use an external transcoder from
    APER to BER and vice-versa.  This was implemented using a proprietary
    ASN.1 compiler / trnaslator which sysmocom is packaging as
    libfftranscode, which is made available as binary package
    for Debian 9 at https://ftp.osmocom.org/binaries/libfftranscode/

Release notes¶

TITAN version 10.0.0 finally brings support for the ASN.1 PER codec:

https://gitlab.eclipse.org/eclipse/titan/titan.core/-/blob/master/usrguide/releasenotes/releasenotes.adoc?ref_type=heads#version-10-0-0

TITAN version 10.1.0 brings some more ASN.1 PER related features/improvements:

https://gitlab.eclipse.org/eclipse/titan/titan.core/-/blob/master/usrguide/releasenotes/releasenotes.adoc?ref_type=heads#version-10-1-0

sadly, version 10.1.0 has a serious regression, so I suggest migrating directly to a path release:

https://gitlab.eclipse.org/eclipse/titan/titan.core/-/blob/master/usrguide/releasenotes/releasenotes.adoc?ref_type=heads#version-10-1-1

Stability, possible regressions, testing¶

Version 10.1.1 was tagged recently, so there may be regressions in the relatively new ASN.1 PER codec or even in other modules of TITAN.
I am running the bleeding edge version 10.1.1 (https://aur.archlinux.org/packages/eclipse-titan) locally and so far haven't caught any bugs (yet).
We'll first need to make sure that all our testsuites are executing fine and exhibit no new regressions, especially those involving the ASN.1 stuff.

Patches¶

Below are patches dropping libfftranscode dependency and migrating to TITAN's new PER codec:

https://gerrit.osmocom.org/c/osmo-ttcn3-hacks/+/37225 {hnbap,ranap,rua,s1ap,sabp,sbcap}: use TITAN's ASN.1 PER codec [NEW]
https://gerrit.osmocom.org/c/osmo-ttcn3-hacks/+/37226 s1ap: add {enc,dec}_S1AP_Global_ENB_ID() API [NEW]

I am marking them Work-in-Progress for now.