About (X)NET & TNC4e
(X)NET is a multi-protocol packet radio node software (digipeater/router) developed by Jimy, DL1GJI, with documentation by Manfred, DL2GWA. Originally created for the German and European amateur radio community, (X)NET has become one of the most capable AX.25 node systems available, supporting up to 250 simultaneous users and node tables of up to 1000 entries. The software supports AX.25, NET/ROM, and FlexNet routing protocols, as well as AXIP and AXUDP over Ethernet — bridging traditional RF packet radio with modern IP networks.
TNC4e Hardware Platform
The TNC4e is a hardware TNC designed by Harald Baumgart, DL4SAI and Jimy, DL1GJI, built around a Motorola MC68302EN processor at 20 MHz with 1 MB RAM (expandable to 3 MB) and 1 MB Flash. It provides three SCC serial channels driving modems up to 1.2 Mbit/s and a built-in 10 Mbit/s Ethernet interface (10Base-T / 10Base-2). (X)NET runs on it as 3NET.APL (V1.39) — and being TNC3-compatible it also runs the full TNC3 software line — turning the unit into an AX.25 digipeater plus NET/ROM and FlexNet router that bridges RF packet radio with IP networking (AXIP/AXUDP, KISS, IPKISS).
FlexNet Routing Protocol
FlexNet, developed by Gunter Jost, DK7WJ, is a network-layer routing protocol for AX.25 packet radio. Unlike NET/ROM which uses a separate Layer 3 header, FlexNet embeds all routing information directly in the AX.25 address field. With FlexNet V3.2, header compression reduces the typical 14–70 byte header down to just 7 bytes, effectively doubling link throughput for short frames. FlexNet features automatic route discovery, loop detection, and full compatibility with both AX.25 v1 and v2, making it ideal for TCP/IP operation over packet radio. The Flexnet Destinations link below shows the real-time routing table of this node.
Station Access
Radio access points for the IW2OHX-4 TNC4e (X)NET node
Local Users Access
144.825 1k2 Bd / 433.725 9k6 Bd via IW2OHX-12
HF Users Access
14105 LSB 1700Hz 300Bd AFSK via IW2OHX-15
14102.2 USB Robust Packet via IW2OHX-15
Info Available on the WEB
Real-time system status and routing information from the (X)NET node