Digital Voice Modes Ports Guide

Every port number here was read from the source: the configuration files and source code of the programs that use them, not from forum posts. Where a number is quoted from somewhere else, it says so.

The distinction that causes most of the confusion

A hotspot uses two entirely different sets of ports, and they are constantly mistaken for each other.

Loopback ports carry traffic between programs on the same device, at address 127.0.0.1. They never touch your network. They never need a firewall rule, and forwarding them achieves nothing.

Internet-facing ports carry traffic between your device and a network or reflector somewhere else. These are the ones that matter when something will not connect.

Inside a hotspot, MMDVMHost handles the radio side and a separate gateway program handles the internet side for each mode. The two halves talk to each other over loopback. So a single DMR contact crosses two ports on the way out: one internal, one external. People reading a configuration file and forwarding what they find there are usually forwarding the wrong one.

1 · Internet-facing ports, by mode

These are the destination ports your gateway connects to. This is the set that matters when something will not connect.

ModeProtocol / networkPortNotes
D-STARDPlus (REF reflectors)UDP 20001The American REF network
DExtra (XRF reflectors)UDP 30001The open alternative to REF
DCS / XLXUDP 30051XLX reflectors accept D-STAR here
CCS7UDP 30062Callsign routing by seven-digit ID
G2 gateway, voiceUDP 40000Also the Icom Terminal / Access Point port
G2 gateway, DD dataUDP 40001The 23 cm data mode
DMRMMDVM / Homebrew to XLXUDP 62030The DMR side of an XLX or URF reflector
MMDVM / Homebrew to BrandMeister, TGIFUDP 62031The usual master port for amateur DMR networks
DMR+UDP 55555DMRplus and the networks that follow it
DMR+ DMO modeUDP 8880Direct mode operation into a reflector
OpenBridgeUDP 62035Network-to-network, not for hotspots — see the sourcing note
System FusionYSFReflectorUDP 42000The open Fusion reflector system
FCSUDP 42001The FCS room servers
P25P25ReflectorUDP 41000
NXDNNXDNReflectorUDP 41400
M17mrefd reflectorsUDP 17000Also the port used between interlinked M17 reflectors
POCSAGDAPNETHandled by DAPNETGateway; the port is set by the DAPNET server you use
One number here is not from primary source. OpenBridge on UDP 62035 is carried over from n6jet.com's own pages rather than read from a configuration file this session. It does not appear in the G4KLX DMRGateway configuration, because OpenBridge is a network-operator facility rather than a hotspot one. Treat it as needing confirmation before you rely on it.

2 · Loopback ports inside a hotspot

These are the defaults in G4KLX's own MMDVM.ini. Every one binds to 127.0.0.1. None of them should ever be forwarded. They are listed so you can recognise them and leave them alone.

ModeMMDVMHost sideGateway sideGateway program
D-STAR2001120010ircDDBGateway
DMR6203262031DMRGateway
System Fusion32004200YSFGateway or DGIdGateway
P253201042020P25Gateway
NXDN1402114020NXDNGateway
POCSAG38004800DAPNETGateway
FM38104810FM gateway
62031 appears in both tables, and that is not an error. DMRGateway listens on 62031 locally for MMDVMHost, and separately connects outward to a DMR master on 62031. Same number, two entirely different jobs, one internal and one external. This single coincidence is responsible for a great deal of misdirected port forwarding.

Other loopback ports you will meet

PurposePortNotes
Fusion parrotUDP 42012Local echo service
YSF to DMR / NXDN / P25 cross-modeUDP 42013 / 42014 / 42015Set in YSFGateway
P25 parrotUDP 42011
NXDN parrotUDP 42021
Network modemUDP 3334 / 3335Only when the modem is reached over the network rather than by serial
Transparent dataUDP 40094 / 40095
MQTTTCP 1883Status messaging between components
GPSDTCP 2947Where an attached GPS receiver is read

3 · If you run a reflector

A reflector is the far end, so it needs ports open inbound. This list is from the URF reflector documentation, which supports the widest range of protocols and therefore the longest list. You only open what you have enabled.

PortWhat it carries
TCP 80, 443The reflector dashboard
UDP 8880DMR+ DMO mode
UDP 10002BrandMeister connection
UDP 10017URF-to-URF interlinking
TCP 10100Transcoder, where one is fitted
UDP 12345, 12346Icom G3 Terminal presence and request
UDP 17000M17
UDP 20001DPlus
UDP 30001DExtra
UDP 30051DCS
UDP 32000USRP — the AllStar connection
UDP 40000Icom G3 Terminal
UDP 41000P25
UDP 41400NXDN
UDP 42000YSF
UDP 62030MMDVM / DMR

4 · The analog linking systems

These are not digital voice, but they are what digital voice bridges to, and their ports turn up in the same firewall conversations.

SystemPortNotes
AllStarLinkUDP 4569IAX2, the protocol AllStar runs on. The AllStarLink manual gives the working range as 4560–4580
UDP 1667VOTER. The manual notes 667 may be needed for legacy reasons
EchoLinkUDP 5198, 5199Voice and control
TCP 5200The directory server
IRLPUDP 2074–2093Audio, bi-directional
TCP 15425, 15426, 15427Control and update
TCP 22SSH, needed only for remote admin help
USRPUDP 32000The plain-audio format used to bridge AllStar to a digital reflector. Both ends are configurable
APRS-ISTCP 14580The standard filtered-feed port

5 · Why a hotspot usually needs no port forwarding at all

This is the part that saves the most time, and it is the opposite of what a lot of guidance assumes.

A hotspot initiates its connections. It reaches out to a master or a reflector, and the replies come back on the connection it opened. An ordinary router allows that without being told, because it is the same thing your web browser does. Nothing needs forwarding for a hotspot to work normally.

Port forwarding becomes necessary only when something outside has to start the conversation:

If a hotspot cannot connect, forwarding is rarely the answer. The usual causes are an outbound firewall blocking UDP or non-standard ports, a network that blocks UDP entirely, or carrier-grade NAT between you and the internet. Forwarding a port inward does not address any of the three.

Where these numbers come from

The mode ports, the loopback ports and the D-STAR protocol numbers were read this session from the projects themselves — the shipped MMDVM.ini, DMRGateway.ini, YSFGateway.ini, P25Gateway.ini and NXDNGateway.ini, and the DStarDefines.h constants in ircDDBGateway. The reflector list is from the URF reflector's own documentation and configuration. M17's port is from mrefd's source and README. EchoLink's ports were confirmed against the SVXLink implementation, which is an independent codebase. IRLP's are from the IRLP FAQ, and AllStar's from the AllStarLink manual.

Ports are configurable in nearly every one of these programs. What is listed here is the default that the software ships with, which is what a network expects unless you have deliberately changed it.

Return to n6jet.com  —  73 de N6JET

Sources: g4klx/MMDVMHost · g4klx/DMRGateway · g4klx/YSFClients · g4klx/P25Clients · g4klx/NXDNClients · g4klx/ircDDBGateway · n7tae/urfd · nostar/mrefd · sm0svx/svxlink · AllStarLink Manual — Managing the Firewall · IRLP FAQ · Handheld and Hotspot Troubleshooting