8 Oct
2025
8 Oct
'25
6:14 a.m.
Dear Osmocom community,
A little over a month ago I announced availability of this new MGW:
https://osmocom.org/projects/retro-gsm/wiki/ThemWi_E1_Abis_MGW
So far only two people responded to this news: Csaba has been testing
this new MGW on his Nokia MetroSite (he and I are working toward adding
AMR support), while Keith took only a passing notice - if I understood
him correctly (please forgive me if I misunderstood!), it looks like
Rhizomatica/TIC no longer operate GSM networks with Ericsson RBS gear,
hence no more need for improved E1 MGW from their side.
However, I am getting a sense that the larger Osmocom community may be
disappointed regarding my choice to develop this improved E1 Abis MGW
as a "rogue" project external to Osmocom, rather than in the form of
patches to osmo-mgw. Therefore, I have given some thought to how it
might be possible to merge this new E1 MGW into mainline Osmocom.
Here are my current thoughts:
1) Integrating improved functionality of tw-e1abis-mgw into osmo-mgw
in a fully unified manner, full coexistence of all existing osmo-mgw
functionality plus all tw-e1abis-mgw functionality within a single
program/process, running on one MGCP port and providing both rtpbridge
and E1 endpoints, is beyond my ability, or at least beyond what I can
do using only my own volunteer time. osmo-mgw code base is extremely
complex, and as much as I dread to say it, insanely and needlessly so
- it is a Gordian knot, and I tend to approach those the way Alexander
did...
2) As an intermediate compromise between the too-difficult goal of
point 1 above and the current status quo of tw-e1abis-mgw existing
externally to Osmocom, how would Osmocom community feel about a
hypothetical osmo-e1-mgw program? Suppose I were to produce patches
that add osmo-e1-mgw as a new program to osmo-mgw git source tree,
such that osmo-mgw and osmo-e1-mgw binaries would be built side by
side in the same source tree - any interest? The actual code bases
compiling into these two binaries would still be mostly separate, just
the autotools infra of osmo-mgw git tree would be shared, but the new
osmo-e1-mgw program would carry Osmocom branding, and it would live in
a mainline Osmocom repository where people other than me can shape its
future direction.
Please note that I don't need this integration for myself: for our own
use on our to-be-built network, we (A2GC) are quite happy running the
hybrid software stack where some components are built from Osmocom
source repositories while other components are built from ThemWi repos.
Instead I am making this offer to Osmocom community for social reasons:
I wish to continue as an active member of this community, if possible,
and fork-like activities are certainly _not_ the way to go, socially.
I am also making this integration offer to the community as food for
thought, without any urgency. If the greater Osmocom community does
wish to see tw-e1abis-mgw turned into something like osmo-e1-mgw,
integrated into mainline Osmocom, it will probably be another few
months before I can start submitting patches in this direction. The
reason for the delay is that tw-e1abis-mgw is not quite finished at
the present moment: two big missing features are AMR support and
UL-to-DL transform (aka TFO transform) for EFR. I would like to fill
these two functional gaps in the new MGW while staying in my own
tw-e1abis-mgw source tree, before beginning the process of merging
into Osmocom mainline - hence the time delay prognosis.
If Osmocom community does wish to see the improved E1 MGW as part of
mainline Osmocom code base, I would need an explicit "green light"
go-ahead before I start preparing any patches. The patch process
would need to proceed as follows:
1) I will need to prepare a patch for libosmocore, adding a header file
with definitions from 3GPP TS 48.103 Table 5.4.2.2.1. Right now ThemWi
software, including tw-e1abis-mgw, uses <themwi/common/aoip_rtp_pt.h>
header file - but of course the latter won't be available in pure
Osmocom environment without ThemWi dependencies.
2) There will need to be a whole bunch of patches to libosmo-abis.git
(libosmotrau portion thereof), adding various functions which I
currently collect in libtwtrau and which will be used by the upcoming
AMR-capable version of tw-e1abis-mgw.
3) Only after 1 and 2 above are merged, then I'll able to produce a
big patch for osmo-mgw.git, adding osmo-e1-mgw (or whatever other name
the community comes up with) as a new program.
In any case, in the immediate short term I am going to continue
improving tw-e1abis-mgw where it lives currently, in ThemWi area of
Osmocom Gitea. Once AMR support and UL-to-DL transform for EFR are
there, I will make another post here. At that point if the greater
community would like to see this work merged, I will need feedback
in this ML thread.
GSM/2G Forever,
Mother Mychaela
9 Oct
9 Oct
10:36 p.m.
I can't tell the future at the moment; I updated the OS on my crystal
ball a few months ago and it still hasn't rebooted yet.
It's quite possible that at some point, somebody might want more 2G
systems, Ericsson or not. Run by Telecomunicaciones Indígenas
Comunitarias, or not, - and/or 2G/LTE or even whateverG else is around then.
Improved MGW support for E1 is of course, er.. an improvement. Lack of
AMR there would be on my list of laments for what I was unable to get
done (yet), along with all those other things to do with audio quality
with AMR + DTX and all those weird things to do with RTP streams and
audio on the radio interface, that Mychaela seems to be quite passionate
about.
Also listed would be, multiple radio support in osmo-bsc on the DUG, and
quite a big lament; - Lack of dual mode radio support for a 2G/4G
combination on one RUS/sector. Anyway, no, I don't have any use case for
it at the moment, and my motivations for spending hours coding 2G had
diminished somewhat along with TIC-AC's changes in direction, and the
pandemic... and the war.. and the genocide.... Besides, after all these
years, well.. the femto BTS (osmo-bts) based systems are working now
very stable, although rough working conditions has taken its toll on a
lot of that radio equipment.
And, it seems the the flood of Ericsson equipment onto the second hand
market that was once anticipated has yet to materialise.
Anyway, all I really wanted to say was that I don't see any evidence
that osmocom community considers anything "rogue" and if that was
interpreted from a comment* of mine, it should not have been.
* now as I write realising that comment was offlist.
12 Oct
12 Oct
7:15 p.m.
On Tue, Oct 07, 2025 at 08:14:39PM -0800, Mychaela Falconia wrote:
So far only two people responded to this news: Csaba
has been testing
...
while Keith took only a passing notice
...
him correctly (please forgive me if I misunderstood!),
it looks like
Rhizomatica/TIC no longer operate GSM networks with Ericsson RBS gear,
hence no more need for improved E1 MGW from their side.
However, I am getting a sense that the larger Osmocom community may be
disappointed
Hi Mychaela,
I would like to reflect that the above paragraphs are very uncomfortable for me
to read.
You do have improved your communication dramatically from the first time we
discussed mailing list netiquette, thank you for that. However, I feel that
this is a subtle gem, and I do see the need to give some feedback.
The points in particular:
Be aware that this is a public forum:
- I would prefer if you let the other developers step into a public thread *if*
they choose to, and not publicly call out names when you don't have to.
- Please do not infer, hypothesize, let alone leak details about how someone else
runs their site. It is their choice to disclose those details publicly -- or
not! It is inappropriate to poke for details there.
Reading that you "sense" that all of us are disappointed by your work reads
like a provocative overstep. We are not close enough that I could in any way be
disappointed.
Let's keep a neutral tone on a technical mailing list:
Please keep your assumptions on low profile,
and please invite instead of poking and prodding.
Thank you!
~N
1
days inactive
5
days old
2 comments
3 participants
participants (3)
-
Keith -
Mychaela Falconia -
Neels Hofmeyr