Yesterday, laforge and manawyrm have managed to establish the first successful calls between two ISDN PBX interconnected via the Proposed_efficient_TDMoIP protocol implemented in osmo-e1d using the icE1usb hardware.
The setup looks as follows:
Using this setup we could validate so far:
- the new, efficient and transparent OCTOI TDMoIP protocol works over public consumer internet access (VDSL on one end / DOCSIS on another end)
- GPS-locked oscillators on both sides provide stable shared clock for cycle-slip free operation
Contrary to other established TDMoIP protocols, it is both transparent / protocol-agnostic and only transmits those timeslots of a E1 PRI circuit that are in use.
We are therefore fairly certain that this setup can be the basis of the larger intended Community_TDMSS7_Network we have in mind. There is lots of work to do, and we appreciate any help (see project issue tracker).
We're happy to announce the next incarnation of OsmoDevCall
This time, laforge will be presenting on Advanced SIM card topics: GlobalPlatform SCP02, OTA, ARA-M, ISIM
The talk covers some of the more advanced topics related to SIM cards:
- GlobalPlatform commands / SCP02 protocol
- OTA (Over The Air) RFM/RAM via TS 03.34
- The ARA-M applet
- The ISIM application
It is expected that the audience is familiar with SIM card basics, such as SIM/UICC/USIM concepts and the general file system abstraction.
When: Friday, February 25, 2022 from 20:00 CET
| Time |
Topic |
Who |
| 20:00 |
Meet and Greet |
everyone |
| 20:10 |
Advanced SIM card topics: GlobalPlatform SCP02, OTA, ARA-M, ISIM |
laforge |
| 21:00 |
USSE (Unstructured Supplementary Social Event) |
everyone |
Where: https://meeting5.franken.de/b/har-xbc-bsx-wvs (Big Blue Button of https://franken.de/) NOTE: URL has changed
We're happy to announce the 23nd incarnation of OsmoDevCall
In this edition, we will not have any presentation, as sadly nobody has volunteered to present this time. Nevertheless, we still hold the call in case anyone wants to chat about random stuff.
When: Friday, February 11, 2022 from 20:00 CET
| Time |
Topic |
Who |
| 20:00 |
Meet and Greet |
everyone |
| 20:10 |
USSE (Unstructured Supplementary Social Event) |
everyone |
Where: https://meeting5.franken.de/b/har-xbc-bsx-wvs (Big Blue Button of https://franken.de/) NOTE: URL has changed!
The pySim source code has contained built-in sphinx based documentation for quite some time, but users had to build the manual locally from source.
A HTML rendering of the [latest git master] pySim user manual is now published at https://downloads.osmocom.org/docs/latest/pysim/ - it is automatically updated via our jenkins CI.
A number of previously unavailable historical German national standards related to (mainly) ISDN have been uncovered and are now availale as PDFs from https://people.osmocom.org/laforge/ftz/ (and in more structured presentation with metadata at German_FTZ_ISDN_Specifications).
The standards include, among many others
- 1TR6 - German National ISDN variant of the 1980ies, before Euro-ISDN was introduced in the 1990ies
- 1TR7 - German National SS7 dialect
- various physical layer specs for interfaces such as S2M, V2M, Uk0, Uk2, UG2 and more
Yesterday, the concepts of the Proposed_efficient_TDMoIP could be validated in practice for the first time using the work-in-progress implementation in the laforge/e1oip branch of osmo-e1d
The setup consisted of two icE1usb USB-E1 interfaces with built-in GPS-DO transporting an E1 line over an intermediate IP network. The clock synchronization has been monitored and sufficient stability over a period of several hours was confirmed, with no underruns/overruns or cycle slips.
The compression feature was working as expected: E1 timeslots with no change compared to the previous frame were supressed. The batching feature (32 E1 frames per UDP packet) was equally working as expected.
There's still a lot of work to do to make this more usable via consume internet connections with NAT and dynamic IP addresses, but the concepts could be shown to work in practice:
- using GPS-DO clocked icE1usb to avoid clock drift
- using batching of E1 frames
- suppressing transmission of timeslots with no data
We're happy to announce the 22nd incarnation of OsmoDevCall
In this edition,
laforge will present a number of brief (
lightning) talks about a number of projects he's currently been thinking about or working on, including
- efficient TDMoIP protocol
- TDMoIP community network
- hardware design of ISDN BRI interface for TDMoIP community network
- continuous testing setup for simtrace2 "cardem" firmware
- non-transparent ISA-over-USB bridge attached to qemu
The idea is to ping-pong some ideas wit others and maybe find somebody interested in helping out.
When: Friday, January 28, 2022 from 20:00 CET
| Time |
Topic |
Who |
| 20:00 |
Meet and Greet |
everyone |
| 20:10 |
series of brief talks on topics stated above |
laforge |
| 21:00 |
USSE (Unstructured Supplementary Social Event) |
everyone |
Where: https://meeting4.franken.de/b/har-xbc-bsx-wvs (Big Blue Button of https://franken.de/)
We're happy to announce the 21st incarnation of OsmoDevCall
In this inaugural 2022 edition, neels will be presenting on Codecs in OsmoMSC, MNCC and SIP.
The talk covers the handling and negotiation of GSM/UMTS voice codecs in the core network, both in current master as well as in a long-standing to-be-merged branch.
When: Friday, January 14, 2022 from 20:00 CET
| Time |
Topic |
Who |
| 20:00 |
Meet and Greet |
everyone |
| 20:10 |
Codecs in OsmoMSC, MNCC and SIP |
neels |
| 21:00 |
USSE (Unstructured Supplementary Social Event) |
everyone |
Where: https://meeting4.franken.de/b/har-xbc-bsx-wvs (Big Blue Button of https://franken.de/)
We're happy to announce the 20th incarnation of OsmoDevCall
In this X-mas special retronetworking edition, laforge will be presenting on The ETSI V5 interface in digital telephone exchanges
The ETSI/ITU V5 interface is an internal interface of a digital telephone exchange (aka "central office") for POTS and ISDN in the PSTN. The talk will introduce the interface and present some ongoing efforts towards a FOSS implementation of it.
When: Tuesday, December 28, 2021 from 20:00 CET (yes, Tuesday instead of Friday this time due to Christmas)
| Time |
Topic |
Who |
| 20:00 |
Meet and Greet |
everyone |
| 20:10 |
ETSI V5 in [historical] digital telephone exchanges |
laforge |
| 21:00 |
USSE (Unstructured Supplementary Social Event) |
everyone |
Where: https://meeting4.franken.de/b/har-xbc-bsx-wvs (Big Blue Button of https://franken.de/)
The history of Osmocom is intertwined with a group of poeple that used to meet at the Chaos Communication Congress.
For more than the past decade, before the pandemic, Osmocom always used to have a physical room at the annual Chaos Communication Congress. Attendees of the event interested in open source mobile communications could just come over and ahve a chat with like-minded people.
In 2021, like in 2020, there is no Chaos Communcation Congress due to the global pandemic.
However, we have created a virtual room (big blue button audio/video conference) where we invite anyone interested to join during the traditional December 27 to December 30 time frame.
The room is called OsmoC3 and you can find it at https://meeting4.franken.de/b/har-ohz-mqu-irn
Merry Christmas, and a Happy New Year,
Harald "LaF0rge" Welte
