AX.25 - Lessons Learned

• Link protocols designed for wired networks (especially by PTT monopolies) don't transition very well to radio.
• Efficient channel access is a serious problem in real networks.
• Pure ARQ doesn't work very well, especially with QRM like 70cm military radar.
• What a link protocol doesn't do is just as important as what it does do (e.g., "connections" are superfluous at the link layer).
• We actually need a variety of link protocols, each suited to a particular channel (wire, HF, VHF/UHF, satellite), and tied together into a uniform internetwork, e.g., with TCP/IP.  CLOVER is one such protocol, specifically designed for HF.  We need more.