Homebrew repeater protocol

At the moment we have two versions of the Homebrew repeater protocol:

• A version that is specified by DL5DI as the result of discussion between DL5DI, G4KLX and DG1HT
• A version that is implemented by G4KLX with his MMDVMHost software

Disclaimer

Connecting to Brandmeister with the Homebrew and MMDVM Host protocols is reserved for repeaters and hotspots with an onboard radio (RF) module.

If you are writing software or building an appliance to connect to Brandmeister without a radio transmitter, you must use a more suitable protocol. Please contact the development team (https://t.me/BRANDMEISTERGENERALSUPPORT) and we will assist you in choosing the best protocol for your application.

If you want to interconnect another amateur radio network with BrandMeister, you must use the Open Bridge protocol. Please post a request on the Brandmeister support platform (https://support.brandmeister.network) for assistance.

If you want to interconnect a non-amateur radio network to BrandMeister, don't.

Do not create software solutions or build appliances without onboard radio modules that impersonate the HomeBrew or MMDVM Host protocols. This configuration might not work with newer versions of BrandMeister and we cannot provide any support for it.

G4KLX MMDVMHost version

This version of the homebrew repeater protocol is implemented at BrandMeister as "MMDVM Host". The protocol is very close to a version of DL5DI but has some principal changes that are not documented in that specification. Over time, changes introduced have alienated these two protocols.

https://github.com/g4klx/MMDVMHost g4klx/MMDVMHost

Publicly-available version as initially specified by DL5DI

You can find the spec here: File:DMRplus IPSC Protocol for HB repeater.pdf This version of the homebrew repeater protocol is implemented at BrandMeister as "Homebrew Repeater"

Please note, this specification is not necessarily complete.

Corrections and additions

• Default UDP port is 62030.
• All messages except DMRD are in text form.
• Repeater ID should be presented as a hexadecimal string of 8 characters in length (except DMRD, which is binary).
• Salt and SHA-256 hash of the authentication protocol should be also presented as hexadecimal strings.
• Use salt value as a string when calculating hash value (see attached PHP example code).
• Configuration protocol has 306 bytes in length.
• Interval of PING messages should be in the range 5 - 15 seconds (5 is preferred for most firewalls).
• When the TX and RX frequencies have same value we consider this case as a connected hotspot in DMO mode.
• In case of DMO hotspot or IP client all DMR traffic should be transmitted with unset bit of selected slot.

Site Beacon and RSSI (extensions)

• Synchronous Site Beacon is very important for passive automatic roaming. We added a special message to the protocol. It should be sent by the server to repeaters. No response is required.
  • Message format:

    RPTSBKN01234567

    Where 01234567 is ID of repeater (hexadecimal string of 8 characters).
• BrandMeister supports handling of RSSI reports:
  • Message format:

    RPTRSSI01234567:1-120.0

    Where
    • 01234567 is ID of repeater (hexadecimal string of 8 characters),
    •  :1 is slot number (:0 for DMO channel, :1 and :2 for Slot 1 and Slot 2),
    • -120.0 is RSSI value in dBm.
  • There is no acknowledge message.

Incoming call interrupt

Client could request server to interrupt current incoming call.

• Message format:

  RPTINTR01234567:1

  Where
  • 01234567 is ID of repeater (hexadecimal string of 8 characters),
  •  :1 is slot number (:0 for DMO channel, :1 and :2 for Slot 1 and Slot 2),
• There is no acknowledge message.

Examples

PHP