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  • Detecting Telnet Echo state?

    From Xucaen@VERT/TIMEPORT to All on Mon May 8 09:27:45 2017
    I've been googling but so far haven't found any answers.
    I wrote a simple socket server in C++. When using
    SyncTerm I must echo back the characters from my server.
    But when using Windows telnet client all characters are
    doubled. Now I tested this same scenario with Synchronet BBS.
    It seems like Synchronet can detect if the telnet client
    has echo on or off. When I use both Windows Telnet and
    SyncTerm I see no doubling of characters - they both seem
    to work just fine. I assume there must be a way for the
    server to detect the echo state of the client but I can't
    find any information about how this is done. Can someone
    point me in the right direction?

    ... "I'll just write my own taglines. How hard could it be?"

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  • From Xucaen@VERT/TIMEPORT to All on Mon May 8 11:50:12 2017
    Re: Detecting Telnet Echo state?
    By: Xucaen to All on Mon May 08 2017 09:27 am

    As with all things, right after posting this message I found the answers I need. My appologies.

    For those interested, it is telnet option 45 to tell the client to either begin local echo or suppress local echo.

    Cheers.

    Jim

    ... "To live between a rock and a hard place, in between time"

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    þ Synchronet þ The Time Portal - timeport.synchro.net:2112 - Home of Labyrinth.
  • From Xucaen@VERT/TIMEPORT to All on Tue May 9 16:52:41 2017
    Re: Detecting Telnet Echo state?
    By: Xucaen to All on Mon May 08 2017 11:50 am

    It appears that both SyncTerm and putty do not respond to terminal option 45. So my question is, how is Synchronet doing this?

    ... "I'm not inclined to resign to maturity"

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  • From Digital Man@VERT to Xucaen on Sat Jun 3 14:20:15 2017
    Re: Detecting Telnet Echo state?
    By: Xucaen to All on Tue May 09 2017 04:52 pm

    Re: Detecting Telnet Echo state?
    By: Xucaen to All on Mon May 08 2017 11:50 am

    It appears that both SyncTerm and putty do not respond to terminal option 45. So my question is, how is Synchronet doing this?

    Synchronet's Terminal Server tells Telnet clients that it will handling the echoing. You can see the Telnet option exchange if you enable Telnet command debug output in the Terminal Server:

    6/3 02:17:49p Node 2 sending telnet cmd: WILL Echo
    6/3 02:17:49p Node 2 sending telnet cmd: WILL Suppress Go Ahead
    6/3 02:17:49p Node 2 sending telnet cmd: DO Terminal Type
    6/3 02:17:49p Node 2 sending telnet cmd: DO Terminal Speed
    6/3 02:17:49p Node 2 sending telnet cmd: DO Send Location
    6/3 02:17:49p Node 2 sending telnet cmd: DO Negotiate About Window Size
    6/3 02:17:49p Node 2 sending telnet cmd: DO New Environment Option
    6/3 02:17:49p Node 2 received telnet cmd: DO Echo
    6/3 02:17:49p Node 2 received telnet cmd: DO Suppress Go Ahead
    6/3 02:17:49p Node 2 received telnet cmd: WILL Terminal Type
    6/3 02:17:49p Node 2 requesting telnet terminal type
    6/3 02:17:49p Node 2 received telnet cmd: WILL Negotiate About Window Size
    6/3 02:17:49p Node 2 received telnet cmd: WON'T Terminal Speed
    6/3 02:17:49p Node 2 sending telnet cmd: DON'T Terminal Speed
    6/3 02:17:49p Node 2 received telnet cmd: WON'T Send Location
    6/3 02:17:49p Node 2 sending telnet cmd: DON'T Send Location
    6/3 02:17:49p Node 2 received telnet sub-negotiation command: Negotiate About Window Size
    6/3 02:17:49p Node 2 received telnet window size: 132x56
    6/3 02:17:49p Node 2 received telnet cmd: WILL New Environment Option
    6/3 02:17:49p Node 2 received telnet sub-negotiation command: Terminal Type
    6/3 02:17:49p Node 2 received telnet terminal type: ANSI
    6/3 02:17:49p Node 2 received telnet cmd: WON'T Terminal Speed
    6/3 02:17:49p Node 2 received telnet cmd: WON'T Send Location


    digital man

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