the value of a fid is a 32-bit number, but a server will typically have a practical upper limit on how many distinct values it can track, limited for instance by memory. in your Arduino case, a dozen or so would normally be plenty, and the server can reject Tattach,Tauth, and Twalk requests with an error if it couldn't handle a client's declaration of a new fid, so it would fail gracefully without disrupting current communications.
- [9fans] 9p specification: minimum number of fids? smiley
- Re: [9fans] 9p specification: minimum number of fids? Charles Forsyth