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OCTOI - Osmocom Community TDM over IP |
||||
===================================== |
||||
:author: Harald Welte <laforge@osmocom.org> |
||||
:copyright: 2022 by Harald Welte (License: CC-BY-SA) |
||||
:backend: slidy |
||||
:max-width: 45em |
||||
|
||||
== Overview |
||||
|
||||
* WTF? Why? |
||||
* History: Telephony / TDM networks |
||||
* existing TDMoIP technology |
||||
* OCTOI Protocol |
||||
* OCTOI Software |
||||
* Current OCTOI Network |
||||
* WIP / Future Plans |
||||
|
||||
|
||||
== Introduction |
||||
|
||||
Some people collect + operate old computers (_retrocomputing_) |
||||
|
||||
... |
||||
|
||||
But what's a 1980s or 1990s computer without it's contemporary networking technology? |
||||
|
||||
== Zyxel V.32bis Modem |
||||
|
||||
image::zyxel.jpg[width=1000,align="center"] |
||||
|
||||
== ELSA MicroLink ISDN TA |
||||
|
||||
image::ELSA_MicroLink_ISDN_2ab_front.jpg[width=800,align="center"] |
||||
|
||||
== TELES S0/16.3 passiver ISDN-Adapter |
||||
|
||||
image::teles_s0_16_3.jpg[width=1000,align="center"] |
||||
|
||||
|
||||
== T-DisplayTel ISDN-BTX-Telefon |
||||
|
||||
image::displaytel.jpg[width=1000,align="center"] |
||||
|
||||
== T-View 100 ISDN-Videotelefon |
||||
|
||||
image::tview100.jpg[width=800,align="center"] |
||||
|
||||
== WTF is this all about? |
||||
|
||||
* enable people to run legacy WAN equipment |
||||
** Modems |
||||
** ISDN-Adapters |
||||
** Phones, PBXs |
||||
** Telefax |
||||
** Frame Relay / HDLC / X.25 / routers |
||||
* in a distributed fashion, over the internet |
||||
* allow to run retronetworking tech from mid-1980s to about 2010 at a time where the related transport |
||||
services are no longer available from public telephone operators / carriers |
||||
|
||||
== Migration paths for ISDN equipment |
||||
|
||||
* SIP ATA |
||||
** provides analog phone jacks on phone side, speaks SIP to operator |
||||
** works fine for voice telephony |
||||
** can occasionally work for Fax |
||||
** doesn't work well for Modems |
||||
|
||||
== Migration paths for ISDN equipment |
||||
|
||||
* Fritzbox with ISDN BRI (S0) port |
||||
** terminates Q.921/Q.931 ISDN protocol stack internally |
||||
** speaks SIP to operator |
||||
** works fine for voice telephony |
||||
** can work for Fax |
||||
** doesn't work well for Modems |
||||
** doesn't work at all for X.25/X.31 |
||||
|
||||
== Migration paths for ISDN equipment |
||||
|
||||
* _enterprise grade_ SIP/ISDN gateways |
||||
** available for BRI (S0) and PRI (E1) |
||||
** typically to help companies avoid replacing their ISDN PBX |
||||
** terminates Q.921/Q.931 ISDN protocol stack internally |
||||
** speaks SIP to operator |
||||
** works fine for voice telephony |
||||
** can work for Fax |
||||
** doesn't work well for Modems |
||||
** doesn't work at all for X.25/X.31 |
||||
|
||||
== VoIP: Why does only voice work well |
||||
|
||||
* well, it's called _voice_ over IP, not _modem_ over ip ;) |
||||
* one problem is audio codecs |
||||
** most VoIP uses lossy compression (think of MP3) |
||||
** lossy codecs work for voice, but nothing else |
||||
** can only be solved if end-to-end VoIP path can be forced to G711 or CLEARMODE |
||||
** depending on situation (involved SIP operators, ...) this may or may not be possible |
||||
* other problem is clocking |
||||
** impossible to solve / work around |
||||
|
||||
== Clocking in synchronous networks vs VoIP |
||||
|
||||
* classic analog networks had analog connection end-to-end. There's constant phase / delay |
||||
* ISDN networks used PDH and later SDH for transmission |
||||
** tight synchronization between the clocks of all central offices |
||||
** clocks means both the sample clock of ADCs/DACs as well as bit clock of ISDN PRI/BRI |
||||
* In VoIP networks everyone uses their own clock source |
||||
** typically a normal XTAL in your ATA / FritzBox with as much as 20 ppm tolerance |
||||
* if clocks between two partners drift, there will be underruns or overruns |
||||
** if this happens, you drop samples or insert samples |
||||
** this creates phase discontinuity |
||||
** modem standards were *not* designed for this |
||||
|
||||
== Modem/ISDN in the VoIP world |
||||
|
||||
* VoIP really is designed for voice only |
||||
** codec issue can be worked around if you can control codecs end-to-end |
||||
** clock issue requires hardware modding your ATA/FritzBox/Gateway |
||||
* you still have no transparency |
||||
** what about ISDN signaling subtleties like HLC/LLC in SETUP? |
||||
** what about X.25 over ISDN D-Channel (X.31) |
||||
|
||||
What you really want a *transparent* way of transporting ISDN/PSTN over IP, not some gateway that's way too high up the protocol stack. |
||||
|
||||
// *********************************************************************** |
||||
// History: TDM networks |
||||
// *********************************************************************** |
||||
|
||||
== History: Analog Telephony Networks |
||||
|
||||
* analog telephony exited (in Germany) since 1877 |
||||
* analog electrical circuit from end to end |
||||
* switching initially manually |
||||
* automatic (electromechanical) switching introduced 1908-1966 |
||||
|
||||
== History: Digitization inside the network |
||||
|
||||
* analog pairs of copper lines |
||||
* carrier frequency systems (TF-Systeme) over coaxial wire |
||||
* first digital PCM (pulse code modulation) links between exchanges |
||||
* digital switching with analog switch matrix (EWS) |
||||
* digital switching with digital switch matrix (EWSD, S12) |
||||
* 1979: decision to migrate entire German PSTN to digital switching |
||||
** estimated completion date in 2018 |
||||
** actual completion of all 6200 exchanges in 1997 |
||||
|
||||
== History: TDM networks |
||||
|
||||
* at some point (1970s?), digital PCM technology was introduced between exchanges |
||||
** initially PDH, later SDH (which can transport PDH) |
||||
** see https://media.ccc.de/v/osmodevcall-20211112-laforge-tdm[OsmoDevCall on TDM/PDH/SDH] |
||||
* external interfaces, particularly to subscriber, still analog until mid-1980s |
||||
* ISDN changed that: Introduced digital subscriber lines |
||||
** Basic Rate ISDN (BRI): 2x B, 1x D-Channel |
||||
*** German: Basisanschluss (Anlagenanschluss, Mehrgeraeteanschluss) |
||||
** Primary Rate ISDN (PRI): 30x B, 1x D-Channel |
||||
*** German: Primaermultiplexer / S2M |
||||
|
||||
== Present: TDM networks mostly dead |
||||
|
||||
* Telcos have meanwhile mostly migrated to All-IP telephony |
||||
* PDH/SDH networks mostly shut down, occasionally still in operation for legacy customers or some internal |
||||
legacy services. Not actively sold anymore. |
||||
* You cannot get a real PRI line anymore to connect your ISDN PBX or your Cisco router |
||||
* Idea: Create community network of people who want to play with ISDN / TDM stuff |
||||
* Naive approach: Use existing, off-the-shelf TDMoIP devices |
||||
|
||||
|
||||
== Wanted: TDMoIP network |
||||
|
||||
[graphviz] |
||||
---- |
||||
graph G { |
||||
hub [shape=box, label="TDMoIP hub\ncross-connect\nin public internet"]; |
||||
subgraph cluster_1 { |
||||
label="Hobbyist A"; |
||||
ad1 [label="Access Device\n"]; |
||||
pbx1 [label="PBX"]; |
||||
phone1a [label="Phone"]; |
||||
modem1b [label="Modem"]; |
||||
ta1c [label="ISDN TA"]; |
||||
pbx1 -- ad1 [label="E1"]; |
||||
phone1a -- pbx1 [label="POTS"]; |
||||
modem1b -- pbx1 [label="POTS"]; |
||||
ta1c -- pbx1 [label="ISDN-BRI"]; |
||||
} |
||||
subgraph cluster_2 { |
||||
label="Hobbyist B"; |
||||
ad2 [label="Access Device\n"]; |
||||
pbx2 [label="PBX"]; |
||||
phone2a [label="Phone"]; |
||||
modem2b [label="Modem"]; |
||||
ta2c [label="ISDN TA"]; |
||||
pbx2 -- ad2 [label="E1"]; |
||||
phone2a -- pbx2 [label="POTS"]; |
||||
modem2b -- pbx2 [label="POTS"]; |
||||
ta2c -- pbx2 [label="ISDN-BRI"]; |
||||
} |
||||
subgraph cluster_3 { |
||||
label="Hobbyist C"; |
||||
ad3 [label="Access Device\n"]; |
||||
pbx3 [label="PBX"]; |
||||
phone3a [label="Phone"]; |
||||
modem3b [label="Modem"]; |
||||
ta3c [label="ISDN TA"]; |
||||
pbx3 -- ad3 [label="E1"]; |
||||
phone3a -- pbx3 [label="POTS"]; |
||||
modem3b -- pbx3 [label="POTS"]; |
||||
ta3c -- pbx3 [label="ISDN-BRI"]; |
||||
} |
||||
ad1 -- hub [label="TDMoIP\nInternet"]; |
||||
ad2 -- hub [label="TDMoIP\nInternet"]; |
||||
ad3 -- hub [label="TDMoIP\nInternet"]; |
||||
} |
||||
---- |
||||
|
||||
// *********************************************************************** |
||||
// Existing TDMoIP technology |
||||
// *********************************************************************** |
||||
|
||||
== Existing TDMoIP: SAToP / CESoPSN |
||||
|
||||
So we just get some of these and all is good? |
||||
|
||||
image::RAD_IPmux-1_front.jpg[width=1000,align="center"] |
||||
|
||||
== Existing TDMoIP: SAToP / CESoPSN |
||||
|
||||
Examples for _transparent_ TDMoIP technologies |
||||
|
||||
* SAToP (Structure Agnostic TDM over IP) |
||||
** RFC 4553 |
||||
* CESoPSN (Circuit Emulation Service over Packet Switched Network) |
||||
** RFC 5086 |
||||
* transport of raw E1 frames over MPLS or UDP |
||||
* designed for use in LAN or carrier backbone networks |
||||
* waste a lot of bandwidth, even if TDM circuits are completely idle |
||||
** > 2Mbps plus header/packet overhead, bi-directional |
||||
* typically no support for dynamic IP addresses |
||||
|
||||
== Existing TDMoIP: SIGTRAN IUA, EL2TPD |
||||
|
||||
Examples for _non-transparent_ TDMoIP technologies |
||||
|
||||
* SIGTRAN IUA (ISDN User Adaptation) |
||||
** RFC 3057 |
||||
** works only for ISDN BRI/PRI with Q.921 as Layer 2 on signaling channel |
||||
** uses SCTP as transport (might not pass all middleboxes in public internet) |
||||
** no specification how the B-channels are handled, pure signaling solution |
||||
* Ericsson L2TP / PacketAbis over IP |
||||
** proprietary, but FOSS implementation in @osmo-el2tpd@ |
||||
** makes specific assumption of use of E1 as Ericsson Abis (GSM BTS back-haul) |
||||
|
||||
// *********************************************************************** |
||||
// OCTOI TDMoIP protocol |
||||
// *********************************************************************** |
||||
|
||||
== The case for a new TDMoIP protocol |
||||
|
||||
There's room for a new protocol based on the following goals: |
||||
|
||||
* *transparent*. Should work for ISDN and other use cases (Frame Relay, Abis, SS7, ATM, ...) |
||||
* *efficient*. Should not waste a lot of bandwidth on an otherwise idle/unused link |
||||
* *dynamic IP*. End-user internet access normally has dynamic IP addresses |
||||
* *nat friendly*. Should work through any number of NATs and CG-NAT without special ALG/helper |
||||
* *IPv6 support*. Should support IPv6 just like IPv4 |
||||
* *authentication*. Should have built-in mutual authentication |
||||
|
||||
== OCTOI Protocol: Bandwidth |
||||
|
||||
* Timeslot Suppression |
||||
** Transmitter has history of 1 TDM frame |
||||
** Before Tx, to-be-transmitted frame is compared with last frame |
||||
** only those timeslots with value != that of last frame are transmitted |
||||
* Batching |
||||
** Batch 32 (up to 40) E1 frames per UDP packet |
||||
*** 8000 frames/s / 32 => 250 packets/s |
||||
|
||||
Result: About 70 kbit/s internet bandwidth use (including UDP + IPv4 overhead) for an idle E1 link |
||||
|
||||
== OCTOI Protocol: dynamic IP / NAT-friendly |
||||
|
||||
* Classic client/server approach |
||||
* Server currently requires fixed IP (no STUN/ICE/...) |
||||
* Clients can have dynamic IPs |
||||
* All messages (control plane + TDM user plan) in one UDP flow |
||||
|
||||
// *********************************************************************** |
||||
// OCTOI Software |
||||
// *********************************************************************** |
||||
|
||||
== First supported OCTOI hardware: icE1usb |
||||
|
||||
* osmocom icE1usb is an open source hardware/gateware/firmware/driver E1 interface |
||||
* originally developed for talking to GSM base stations |
||||
* contains a GPS disciplined oscillator for high-precision bit clock timing |
||||
* further reading |
||||
** https://osmocom.org/projects/e1-t1-adapter/wiki/IcE1usb |
||||
** https://media.ccc.de/v/osmodevcon2019-97-software-defined-e1 |
||||
|
||||
image::icE1usb-usb_side.jpg[width=550,align="center"] |
||||
|
||||
== E1oIP: osmo-e1d + icE1usb |
||||
|
||||
* osmo-e1d was the first (libusb, userspace) driver for the icE1usb hardware |
||||
* traditionally, it sits between icE1usb hardware and applications using E1 like osmo-bsc |
||||
* instead of a local application, it can now interface icE1usb to OCTOI |
||||
** `octoi-server` mode |
||||
** `octoi-client` mode |
||||
|
||||
First 5 OCTOI users were connected to the hub that way |
||||
|
||||
[graphviz] |
||||
---- |
||||
graph { |
||||
rankdir=LR; |
||||
subgraph cluster_L { |
||||
label="Site L"; |
||||
PBX_L [label="PBX"]; |
||||
icE1usb_L [label="icE1usb"]; |
||||
GW_L [label="GW L"]; |
||||
PBX_L -- icE1usb_L [label="E1"]; |
||||
icE1usb_L -- GW_L [label="USB"]; |
||||
} |
||||
subgraph cluster_R { |
||||
label="Site R"; |
||||
PBX_R [label="PBX"]; |
||||
icE1usb_R [label="icE1usb"]; |
||||
GW_R [label="GW R"]; |
||||
PBX_R -- icE1usb_R [label="E1"]; |
||||
icE1usb_R -- GW_R [label="USB"]; |
||||
} |
||||
Internet; |
||||
GW_L -- Internet [label="IP"]; |
||||
GW_R -- Internet [label="IP"]; |
||||
} |
||||
---- |
||||
|
||||
== E1oIP: osmo-e1d + dahdi-trunkdev |
||||
|
||||
* having one icE1usb per peer/user doesn't scale at the hub |
||||
* this triggered the development of `dahdi-trunkdev` |
||||
** virtual E1 _span_ for DAHDI without any real hardware |
||||
** simply provides stream of E1 frames on a character-device |
||||
** can be used to implement any virtual TDM interface/protocol |
||||
* osmo-e1d was extended to open dahdi-trunkdev instead of icE1usb |
||||
|
||||
This has become the only method of connecting to the OCTOI hub in September 2022 |
||||
|
||||
[graphviz] |
||||
---- |
||||
graph { |
||||
rankdir=LR; |
||||
subgraph cluster_L { |
||||
label="Site L"; |
||||
PBX_L [label="PBX"]; |
||||
icE1usb_L [label="icE1usb"]; |
||||
GW_L [label="GW L"]; |
||||
PBX_L -- icE1usb_L [label="E1"]; |
||||
icE1usb_L -- GW_L [label="USB"]; |
||||
} |
||||
subgraph cluster_R { |
||||
label="Site R"; |
||||
PBX_R [label="PBX\n(Virtual DAHDI)"]; |
||||
} |
||||
Internet; |
||||
GW_L -- Internet [label="IP"]; |
||||
PBX_R -- Internet [label="IP"]; |
||||
} |
||||
---- |
||||
|
||||
// *********************************************************************** |
||||
// Current OCTOI Network |
||||
// *********************************************************************** |
||||
|
||||
== Current OCTOI network hub |
||||
|
||||
[graphviz] |
||||
---- |
||||
graph G { |
||||
subgraph cluster_colo { |
||||
label = "Co-Located Hub"; |
||||
divf [label="DIVF\nCentral Switch",shape="house"]; |
||||
icE1usb; |
||||
pm3 [label="Livingston Portmaster 3"]; |
||||
as54 [label="Cisco AS5400"]; |
||||
icE1usb -- divf [label="E1 (timing master)"]; |
||||
pm3 -- divf [label="E1"]; |
||||
as54 -- divf [label="7xE1"]; |
||||
} |
||||
divf -- laforge [label="TDMoIP"]; |
||||
divf -- manawyrm [label="TDMoIP"]; |
||||
divf -- gruetzkopf [label="TDMoIP"]; |
||||
divf -- roox [label="TDMoIP"]; |
||||
divf -- DrDeke [label="TDMoIP"]; |
||||
etc [label="other users..."]; |
||||
divf -- etc [label="TDMoIP"]; |
||||
} |
||||
---- |
||||
|
||||
* DIVF: Debian 11 with `dahdi-trunkdev`, `osmo-e1d` and `yate` |
||||
* 2x TE820 8-port E1 cards, attaching to |
||||
** icE1usb (clock source) |
||||
** Livingston PortMaster 3 RAS |
||||
** Cisco AS5400 RAS |
||||
|
||||
== Rack view |
||||
|
||||
image::octoi_hub-colocated.jpg[width=900] |
||||
|
||||
== 1U Enclosure with APU, icE1usb, OVP |
||||
|
||||
image::octoi_hub-ice1usb.jpg[width=1100] |
||||
|
||||
== GPS Antenna mounted on the roof |
||||
|
||||
image::octoi_hub-gpsant.jpg[width=600] |
||||
|
||||
this is an old antenna mount previously used for a satellite dish |
||||
|
||||
== GPS Antenna mounted on the roof |
||||
|
||||
image::octoi_hub-gps.jpg[width=1200] |
||||
|
||||
|
||||
|
||||
== Current OCTOI participants |
||||
|
||||
The hub currently has the following clients / participants: |
||||
|
||||
* using icE1usb at hub side |
||||
** laforge |
||||
** manawyrm |
||||
** gruetzkopf |
||||
** roox |
||||
** cquirin |
||||
** drdeke |
||||
** tmwawpl |
||||
** tom/sirtux |
||||
** tnt |
||||
** marrold |
||||
|
||||
== Current OCTOI services |
||||
|
||||
* E1 / TDM as "transport" layer |
||||
* ISDN network as "routing" layer |
||||
** hub simulates the network / central office / switch side |
||||
** client devices implement the "user" side, just like when attaching to ISDN/PSTN |
||||
* Services on top of ISDN |
||||
** Audio Telephony |
||||
** Video Telephony (T-View 100 / H.320) |
||||
** ISDN Data Calls |
||||
** Analog Modem Calls |
||||
** Telefax |
||||
|
||||
== OCTOI ISDN / Modem calls |
||||
|
||||
* hub currently has a https://osmocom.org/projects/retronetworking/wiki/Livingston_Portmaster_3[Livingston Portmaster 3] RAS |
||||
** up to 30 ISDN data or analog modem calls (up to V.90) |
||||
* services can be created in RADIUS, identified by Called Party Number |
||||
** PPP dial-up locally terminated |
||||
** PPP dial-up with forwarding of data via L2TP to remote LAC |
||||
** telnet or TCP clear forwarding to remote BBSs |
||||
* Cisco AS5400 with much higher capacity is waiting to be provisioned |
||||
|
||||
== Challenges: Clocking |
||||
|
||||
* TDM networks need a stable bitclock at all parts of the network |
||||
* everyone must transmit and receive at the same rate of bits / frames |
||||
* we use GPS disciplined oscillators (GPS-DO) to ensure same clock everywhere |
||||
** this avoids overruns / underruns resulting in cycle slips that would create phase discontinuity for |
||||
any modem signals carried over the network |
||||
|
||||
== Challenges: Packet Re-ordering |
||||
|
||||
* It seems like particularly on DOCSIS there is quite a bit of UDP packet re-ordering |
||||
* Initially, osmo-e1d used a FIFO and dropped all out-of-order packets |
||||
* later, we introduced a RIFO (Random In, First Out) to support re-ordering without loss |
||||
|
||||
== Challenges: Packet Loss |
||||
|
||||
* There is quite a bit of packet loss on the public internet |
||||
* People probably don't generally notice much, as most services use TCP or retransmit UDP |
||||
* Surprisingly, I couldn't find any comprehensive studies / research papers on packet loss behaviour of |
||||
consumer internet that are less than 10 years old? |
||||
* Right now we just accept it exists |
||||
* Some early thoughts and experiments on FEC (Forward Error Correction) |
||||
|
||||
== Challenges: Latency |
||||
|
||||
* intercontinental public IP can easily reach >= 200ms RTT |
||||
* ISDN timers in Q.921 and Q.931 are luckily working just fine over that kind of RTT |
||||
* some suspicion that the high latency might have negative impact on Fax (T.30 timers) and modems (buffer |
||||
sizes). I'm personally not yet convinced it is really an issue. |
||||
|
||||
== Current Services on top of OCTOI ISDN |
||||
|
||||
* Participants can call each other for any ISDN call/bearer type |
||||
* Central hub provides |
||||
** Dial-Up (Modem up to V.90 + ISDN V.120/X.75) access |
||||
*** Tons of telnet-reachable BBSs all around the world |
||||
*** BTX (an instance of Neu-Ulm courtesy of https://btx-museum.de/) |
||||
**** unfortunately currently still crashes ISDN BTX Terminal T-DisplayTel |
||||
*** Fax gateway (WIP) |
||||
* Some other users provide |
||||
** Video on demand for ISDN video telephony |
||||
** Remote DOOM for ISDN video telephony |
||||
** Chiptune audio on demand via voice calls |
||||
|
||||
https://osmocom.org/projects/octoi/wiki/Phonebook |
||||
|
||||
== What do I need to connect to the network? |
||||
|
||||
* Currently, we only offer PRI (E1) service, so you need |
||||
** an icE1usb plus some Linux USB host (Raspi, beaglebone, ...) |
||||
** some equipment that talks E1, like an _enterprise_ PBX |
||||
*** Auerswald COMmander2 Basic with S2M is a popular and widely available choice |
||||
*** this PBX then offers analog and BRI ports for your phones / modems / TAs |
||||
|
||||
== The setup used to connect KNF-Kongress |
||||
|
||||
* 19" Version of Auerswald COMmander2 Basic PBX |
||||
* sufficient space internally to put Beaglebone + icE1usb inside |
||||
|
||||
image::octoi-event-pbx.jpg[width=1100] |
||||
|
||||
|
||||
== What will I need to connect to the network? |
||||
|
||||
* We're working on a small, low-power fully integrated device |
||||
* Ethernet/IP connection towards Internet / OCTOI hub |
||||
* 2x S0 (BRI) ports for your ISDN equipment, or analog phones via a/b TA |
||||
* First prototype looks promising. Main work pending is the uC software. |
||||
|
||||
image::osmo-xhfc2su-breakout.jpg[width=1100] |
||||
|
||||
// *********************************************************************** |
||||
// Future Plans |
||||
// *********************************************************************** |
||||
|
||||
== Future Plans |
||||
|
||||
* ISDN BRI (S/T) access to OCTOI network |
||||
** more end-user friendly; many people have S0 equipment and no E1/S2M PBX at home |
||||
* Frame Relay switch / hub |
||||
** second, additional service, completely independent of the current ISDN service |
||||
** initial testing has confirmed HDLC / FR over OCTOI works without problems |
||||
* X.25 network support |
||||
** X.25 access via ISDN D-Channel (X.31) |
||||
* exhibits at hacker and vintage computing events (like VCFB!) |
||||
|
||||
== ISDN BRI (S/T) access to OCTOI |
||||
|
||||
* BRI (ISDN basic rate aka "S/T" aka "S0") support in OCTOI protocol |
||||
* BRI hardware with 2x S/T interface and GPS-DO |
||||
** unlike icE1usb: Ethernet/IP support, not USB |
||||
** complete _appliance_ for OCTOI client mode: no need for computer |
||||
** Status: design of first break-out / evaluation board for ISDN BRI side complete |
||||
** Software not even started yet. Idea is to use Nuttx on Atmel SAMV71 |
||||
|
||||
== Longer-Term Future Plans |
||||
|
||||
* improve FOSS soft-modem situation (linmodem, spandsp) |
||||
* investigate somewhat limited V.90 performance so far |
||||
* support for other Q.931 dialects than DSS1 (like 1TR6 or even NI1) |
||||
* dive into H.320 / H.221 to have software endpoint for ISDN video phones |
||||
|
||||
|
||||
== Thanks |
||||
|
||||
Thanks to |
||||
|
||||
* Sylvain "tnt" Munaut for icE1usb and all his help |
||||
* All of the early OCTOI network participants manawyrm, gruetzkopf, roox, DrDeke, tmwawpl, cquirin |
||||
* noris.net for sponsoring the co-location of the OCTOI hub |
||||
|
||||
== Further Reading |
||||
|
||||
* https://osmocom.org/projects/octoi/wiki[OCTOI Project Homepage/Wiki] |
||||
* https://osmocom.org/projects/octoi/wiki/Proposed_efficient_TDMoIP[OCTOI Protocol Description] |
||||
* https://osmocom.org/projects/retronetworking/wiki[Retronetworking Wiki] |
||||
* https://osmocom.org/projects/osmo-e1d/wiki/Wiki[osmo-e1d software] |
||||
* https://osmocom.org/projects/octoi/wiki/Proposed_efficient_TDMoIP[icE1usb hardware] |
||||
|
||||
|
||||
== Grafana / Stats |
||||
|
||||
Let's have a look at the statistics... |
||||
|
||||
|
||||
== Modem call |
||||
|
||||
Let's demo a modem call |
||||
|
||||
== EOF |
||||
|
||||
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