Sebb, That's what I feared. The remote device I'm connecting to doesn't add any of the padding on 0xFF bytes, so it looks like I can't use the TelnetClient. Fortunately, for my needs a simple Socket connection should work fine.
Thanks, Andrew On Tue, Dec 9, 2014 at 8:10 AM, sebb <[email protected]> wrote: > On 9 December 2014 at 02:15, Andrew Kolbus <[email protected]> > wrote: > > I am using the TelnetClient from commons-net 3.3 in JDK 8. When I try to > > receive xmodem data over a telnet session, some bytes do not make it > through > > to my code. > > > > Example: > > The remote device sends this (confirmed using windows network monitor): > > 01 01 FE [...] C0 00 FF FF FF 00 00 00 00 27 27 00 [...] (133 byte > > xmodem-crc packet) > > > > However, from the telnet client, I get this: > > 01 01 FE [...] C0 00 FF 00 00 00 27 27 00 [...] (130 bytes total) > > > > From what I have read, this is related to NVT. It looks like it is > > converting [FF FF] to [FF] (removing one byte), and just outright > removing > > [FF 00] (removing another two bytes for a total of three). > > Yes, that is what the RFC mandates: > > https://tools.ietf.org/html/rfc856#section-5 > > In binary mode, IAC (FF) is still required to be recognised. > > > I tried using telnetClient.addOptionHandler(new > > SimpleOptionHandler(TelnetOption.BINARY, true, true, true, true));, but > that > > did not change the data I received. > > > > A sample of the code I used to discover the issue is attached. Is there > a > > way to get the TelnetClient to pass all data through? > > No, that would violate the RFC. > > https://tools.ietf.org/html/rfc856#section-5 > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [email protected] > > For additional commands, e-mail: [email protected] > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
