KISS over TCP

A network TNC is a TNC you reach over TCP instead of a cable or a pairing: Direwolf running on a shack computer, or any other software or hardware TNC that serves KISS on a network port. The app connects to it like a client, and from there the channel behaves like every other radio link.

When this is the right choice

• A shack computer with a soundcard TNC. Direwolf attached to a radio does the modulating and demodulating; the phone becomes the APRS station that uses it — messaging, beaconing, the packet log, all over the shack radio.
• SDR receive setups. A receive chain built around an SDR feeding Direwolf gives the app RF receive coverage with no transmitter involved.
• Testing. A software TNC on your own network is the easiest way to watch the app talk KISS without dedicating hardware to it.

If the TNC is a physical box next to you rather than a program on the network, one of the direct connections fits better — Bluetooth, Bluetooth LE, or USB. And a network TNC is not APRS-IS: this channel speaks raw KISS to a modem on a radio, not the internet backbone.

Set it up

1. Open the Radio screen (under More on the tab bar) and tap Add channel.
2. Pick Network TNC — "KISS over TCP — Direwolf or any network TNC".
3. Enter the Host — the address of the machine running the TNC, such as 192.168.1.50 or direwolf.local — and the Port.

The port defaults to 8001, and the screen says why: "Direwolf listens on 8001 unless it was told otherwise." In Direwolf's configuration that is the KISSPORT setting. If you paste a combined host:port address into the Host box, the app splits it into the two fields for you — that is how a KISS server is usually written down.

Switch the channel on and it shows what it is doing: "Connecting to 192.168.1.50:8001", then the link's own state — CONNECTING, CONNECTED, RECONNECTING. If the connection drops, the app keeps retrying on its own.

The same-network requirement

The phone has to be able to reach the host. In practice that means both on the same Wi-Fi/LAN, or connected through a VPN that puts them on one network. A TNC on your home LAN is not reachable from a mobile connection out in the world unless you have arranged that yourself — and exposing a raw KISS port to the open internet is not something to do casually, since anyone who finds it can transmit through your radio.

Also check the TNC's side: Direwolf must actually be listening (KISSPORT 8001 in its configuration), and the computer's firewall must allow the connection in.

A quiet link

Once connected, the channel row counts frames received and sent, and a link that is up but hearing nothing shows CONNECTED · QUIET rather than claiming either success or failure. A quiet channel is normal in a low-traffic area. If nothing is ever received, look at the far end first: is Direwolf decoding anything itself? Its own log prints every packet it hears, which cleanly splits "the radio side is silent" from "the network side is broken".

A network TNC channel sits alongside your other connections — you can run it together with APRS-IS, a Bluetooth TNC, or the audio modem, and pick which links carry each beacon. See Connect a radio for how channels work together.

Last updated 31 August 2026