Setting up Dummy and LogCollector for a TETRAPack connection

Disclaimer:

Please note you follow this guide at your own risk! This is an experimental bridge, and we can't be held responsible if anything bad happens to your precious CTS!

This guide is for a Single-BS (one CTS) subnet. If you wish to interconnect more CTSes locally, you'll need to modify the network topology + E1 time slotting accordingly.

Hardware requirements

Raspberry Pi (4 is ideal, 2GB is ok), with PSU and SD card
icE1USB
A USB-Ethernet Adapter
A CTS (DUH)

Prep work

Make sure you understand how TetraPack works, its topology, how Dummy and LogCollector operate with each other, etc.
Before going any further, read this!
Open up the icE1USB (from the back, with the SMA connector), and swap the jumpers so they match this picture:

CTS Setup

Get a clear view of how the CTS is configured, and its necessary configuration files: bssparams.txt, set_x_gp, gm, sc, sub.csv, etc. Please make sure everything works as a standalone site before starting this entire endeavour!
You also need good way to remotely connect to the CTS management interface (VNC is a good option).
Plan ahead and make a list of the BrandMeister TGs you want your CTS to handle. Add them already to set_x_gp and gm.csv, reboot everything and make sure they already work locally in standalone mode.

Open up bssparams.txt on your CTS, and do the following edits. Don't change anything else at this state:

## Base-Station Parameters ################################################################
#### Set the name to something simple, short, no special caracters
/base-station/name = "CTSNAME";
#### set this to id 1
/base-station/base-station-id = 1;
#### add or replace:
/base-station/standalone-mode = false;
#### add or replace:
/base-station/use-local-site-fall-back = false;

## SDS Gateway Parameters #################################################################
#### Remove all other lines, replace by:
/system/sds-gateway/host-1 = { issi = 262999; ip-address = "44.225.64.18";};
/system/sds-gateway/host-2 = { issi = 250999; ip-address = "44.225.64.19";};
/system/sds-gateway/host-3 = { issi = 16777184; ip-address = "44.225.64.20";};

## E1 Layout Parameters ###################################################################
### Remove all other E1 layout lines, and replace byt this:
/network/E1-layout/time-slot-01 = { source-type = "SIGNALLING"; };
/network/E1-layout/time-slot-02 = { source-type = "SIGNALLING"; };
/network/E1-layout/time-slot-03 = { source-type = "SIGNALLING"; };
/network/E1-layout/time-slot-04 = { source-type = "SIGNALLING"; };

/network/E1-layout/time-slot-17 = { source-type = "BS"; base-station-id = 1; l-transceiver-id = 11; };
#Dummy transceivers
/network/E1-layout/time-slot-22 = { source-type = "BS"; base-station-id = 7; l-transceiver-id = 11; u-transceiver-id = 12;};
/network/E1-layout/time-slot-23 = { source-type = "BS"; base-station-id = 7; l-transceiver-id = 13; u-transceiver-id = 14;};
/network/E1-layout/time-slot-24 = { source-type = "BS"; base-station-id = 7; l-transceiver-id = 15; u-transceiver-id = 16;};

/network/E1-layout/time-slot-25 = { source-type = "DISP"; };
/network/E1-layout/time-slot-26 = { source-type = "ISDN"; };

/network/E1-layout/time-slot-27 = { source-type = "ISDN"; };
/network/E1-layout/time-slot-28 = { source-type = "ISDN"; };
/network/E1-layout/time-slot-29 = { source-type = "ISDN"; };


## Network Topology Parameters ############################################################
#### Remove all other network topology parameters, and replace by this. Don't forget to change CTSNAME to the same name as in line 3!
/network/topology/gateway-pc     = { name = "Gateway Server"; E1-connection-1 = "BS-7"; };
/network/topology/base-station-1 = { name = "CTSNAME"; E1-connection-1 = "BS-7"; };
/network/topology/base-station-7 = { name = "DUMMY"; E1-connection-1 = "BS-1"; E1-connection-2 = "GW-PC"; };

Save and reboot the CTS, make sure it still works.
Copy bssparams.txt over to your local PC, you'll need it for your Raspberry Pi.
Write down the IP address of your CTS BSC computer (mine was 10.10.15.31, but yours will probably be different).

Software Stack Install

Prepare an SD card with a 64-bit Raspbian Bullseye (Debian 11)

Update/Upgrade the OS after boot:

sudo apt get update && sudo apt upgrade
reboot

Add the Osmocom repo, as per Osmocom's documentation:

sudo su
OSMOCOM_REPO="https://downloads.osmocom.org/packages/osmocom:/latest/Debian_11" 
wget $OSMOCOM_REPO/Release.key
mv Release.key /etc/apt/trusted.gpg.d/osmocom-latest.asc
echo "deb [signed-by=/etc/apt/trusted.gpg.d/osmocom-latest.asc] $OSMOCOM_REPO/ ./" > /etc/apt/sources.list.d/osmocom-latest.list
apt get update

Install Osmocom E1D:
```
sudo apt install osmo-e1d
```

Add the TetraPack repository:

wget https://packages.tetrapack.online/install/public.key
mv public.key tetrapack.asc
sudo apt-key add tetrapack.asc
sudo echo "deb [arch=arm64] http://packages.tetrapack.online/repository/ bullseye main" > /etc/apt/sources.list.d/tetrapack.list
sudo apt update

Install TetraPack dummy and cts-logcollector

sudo apt install tetrapack-dummy cts-logcollector

Plug in the icE1USB to your Rpi, recover the interface serial number:
```
sudo lsusb -d 1d50:6145 -v 2> /dev/null | grep iSerial
```

Open (with for instance nano) /etc/osmocom/osmo-e1d.cfg, copy/paste this:

log syslog daemon
e1d
	interface 0 icE1usb
	usb-serial [interface serial number]
	line 0

Reload the service:
```
sudo systemctl restart osmo-e1d
```

Dummy - E1 Link setup

Make sure Dummy is off with:

sudo systemctl stop dummy@default.service

Open/Create /opt/TetraPack/bssparams.txt, and copy/paste the contents from the file created at the CTS setup step. Edit the following lines


## System Parameters #####################################################################
### Edit/Replace
/system/name = "DUMMY";


## Base-Station Parameters ################################################################
### Edit/Replace
/base-station/name = "DUMMY";
/base-station/base-station-id = 7;

Open/Create /opt/TetraPack/default.env

# E1D interface and line in format [interface number].[line number]
DUMMY_LINE=0.0

# Path to CTS topology file (bss3.txt or bssparams.txt)
DUMMY_TOPOLOGY=/opt/TetraPack/bssparams.txt

# IP address and mask for CTS VTUN interface
DUMMY_NETWORK="192.168.0.8 mask 255.255.255.0"

# Specific options (multiple values can be delimited with comma):
# replace-forwarded-link-status - replace IP-forwarded status for both E1 lines status of local BSs/GWPC to up
# emulated-bs-line1-down        - set E1-1 status of emulated BS to down
# emulated-bs-line2-down        - set E1-2 status of emulated BS to down
# emulated-gwpc-line1-down      - set E1-1 status of emulated GWPC to down
# emulated-gwpc-line2-down      - set E1-2 status of emulated GWPC to down
DUMMY_OPTION=emulated-gwpc-line1-down

# Server connection URI in format http(s)://[user]:[password]@[address]/[path and parameters]
# If you care about securely stored password, please put credentials into /opt/TetraPack/.netrc (man netrc)
# REPLACE YOURDMRID with your radio ID :)
DUMMY_CONNECTION="http://<YOURDMIRID>:passw0rd@master-test.dstar.su:8081/dummy/?mode=bs+gwpc"

# Instance name for D-BUS IPC interface
DUMMY_INSTANCE=default

Save everything, cross your fingers and connect E1.1 from your BSC to the left port of icE1usb, like so:
The matching LED on the port should stop blinking, and the red LED on E1-1 should turn off.

Try to start dummy from the console:

cd /opt/TetraPack
./run.sh default.env
#If you see, in blue, "Q.921 connection established", congratulations! Your E1 link works!
#You should also see "Socket Connection Established"

If everything works, Ctrl+C to stop the console instance, and enable the service + start it
```
sudo systemctl enable dummy@default.service
sudo systemctl start dummy@default.service
```

LogCollector - CTS Management interface setup

Connect the USB/Ethernet interface to the Pi, and connect an Ethernet cable from BSC management port to the usb dongle.

Stop LogCollector:

sudo systemctl stop cts-logcollector@default.service

Set a static IP on the interface (probably eth1) on the same range as the BSC, by editing /etc/dhcpcd.conf and adding this:

#Don't forget to edit your ip address to match the range of your BSC!
interface eth1
static ip_address=10.10.15.20
static routers=10.10.15.1

Test if you can connect via telnet:

telnet [BSC IP ADDR] 51600
#If you get "220 Network Management Interface is ready.", you're good to go!

~~Stop~~Through ~~LogCollector:~~that telnet interface, you can check if you got a good E1 link with Dummy:

sudologin systemctla
stopcd cts-logcollector@default.servicenetwork
netstat
#Look at the table that pops up, and focus on the "Links" column
#260-rsp
#260-Node    Links     DD      AI    ISDN    DISP
#260---------------------------------------------
#260-BS-1      u -      u       u       -       -
#260-BS-2      ? ?      ?       ?       -       -
#260-BS-3      ? ?      ?       ?       -       -
#260-BS-4      ? ?      ?       ?       -       -
#260-BS-5      ? ?      ?       ?       -       -
#260-BS-6      ? ?      ?       ?       -       -
#260-BS-7      u u      u       u       -       -
#260-BS-8      ? ?      ?       ?       -       -
#260-GWPC      d u      u       -       u       d
#260-
#260 .
#BS-1 should have first link on U, BS-7 should have both U, and GWPC should have D U
#If it's not the case, check the topology with:
cd topology
ls
#Should show this: 
#260-      d-- gateway-pc
#260-      d-- base-station-1
#260-      d-- base-station-7
#If not, check your bssparams.txt on both the CTS and the Pi, something is wrong.

Open /opt/LogCollector/default.env, and change the ip address:

# [IP of basestation] [dummy instance name] [basestation ID (1-8)]
COMMAND_ARGUMENTS=[YOUR BSC IP] default 1

Enable/Restart LogCollector, wait for a bit and see if you get data coming from the CTS when you place a call or attach to a group:

sudo systemctl enable cts-logcollector@default.service
sudo systemctl start cts-logcollector@default.service
#Let's monitor syslog to see if it recovers logs from the CTS. You should see a bunch of lines show up.
tail -f /var/log/syslog | grep cts

If it works, great! LogCollector is ready. Ctrl+C to quit tail, carry on to the rest