ISDN POTS V5 Event Configuration

This page documents the configuration of our ISDN/POTS V5 access network for evens like the ISDN_at_CCC_Camp_2023

Nokia EKSOS wooden racks

We currently have 3 setups using NOKIA EKSOS N20 racks. They contain:

  • Nokia EKSOS N20 shelf
    • NCU (main CPU card) with V5/E1 and Q3/Ethernet interfaces
    • any number of PSTN + ISDN BRI line cards (PSTN: 32 ports per card, ISDN: 16 ports per card)
    • home-made unit for N20 shelf containing
      • nanopi R5S as Linux SoM
        • LAN1 port used for Q3 to NCU
        • WAN port used for uplink/back-haul\
        • special re-work applied internally to power the R5S from 12V DC without any USB-PD logic
      • icE1usb as USB-E1 interface towards the NCU
  • 48V power supply (trimmed up to ~ 52V) for N20 shelf
  • 12V power supply for fans + nanopi R5S
  • 3x 120mm fan (1200 rpm) 12V mounted above N20 rack, airflow in upwards direction
  • 50-port ISDN patch panel configured as
    • ports 1-16: first 16 ports of PSTN card in slot U3
    • ports 17-32: first 16 ports of PSTN card in slot U5
    • ports 33-48: ISDN line card in slot U7
    • ports 49-50: unused

nanoPi R5S configuration

The nanoPI R5S is configured as follows:
  • Plain Debian 12 installation using
  • osmo-e1d package from osmocom:nightly feed
    • octoi client to connect to remote octoi server
  • network config
    • DHCP on the wan port (back-haul/uplink)
    • software-bridging (q3br) between lan1 and a q3vx VXLAN device using group 3 on multicast group on the wan port
    • static IP on the lan2 port (local admin port)

V5 configuration

Each AN is configured to have
  • one V5 Interface (ID see below)
    • one Link in each V5 interface (Link Id 1)
      • one C-Channel (0) on TS16 of Link 1
    • Startup behaviour: V2
    • Accelerated unblocking: Yes
    • Disable Link ID Checking: Yes
    • Startup during PSTN failure: No
Name Datenklo Number Q3 MAC V5 Interface ID R5S WAN MAC R5S WAN IP e1_line
Berlin Q13 A108.2 00:40:43:f8:55:4a 7108 b4:22:52:84:71:26 4
Leipzig Q8 A096.1 00:40:43:f8:a3:2a 7096 28:2c:44:56:31:22 5
Hamburg A107.1 00:40:43:f9:a2:d8 7107 64:2e:f8:00:66:76 3

Siemens Fastlink


Updated by jolly 4 months ago · 10 revisions

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