[Info-vax] yet another sys$qiow question

[Johnny Billquist]

On 2015-08-12 10:12, Jan-Erik Soderholm wrote:
> Den 2015-08-12 kl. 01:53, skrev Johnny Billquist:
>> On 2015-08-12 00:38, kc at kayceesoftware.com wrote:
>>> this is slightly related issue only as it pertains to the same serial
>>> comm to a card reader.
>>> to refresh: vms 8.4 IA64, tcpip 5.7 ECO 5, C 7.3-018
>>> sys$qiow working fine now and seems very stable, my problem was getting
>>> the terminator mask correct.
>>>
>>> I've been reading on sockets and will be converting to that mode soon
>>> for
>>> another project and probably change this serial code at that point.
>>>
>>> BUT, in researching a very random NAK of my comm, i've found that the
>>> CRC
>>> sometimes calcs a line feed (LF, ox0a), and the stored string shows ONLY
>>> the LF i put in it....but the message that ends up at the card reader
>>> has
>>> CRLF, which is then rejected as invalid.
>>>
>>> The terminal port (TNA1) is set pasthru, the VMS IO Ref Manual says
>>> IO$M_NOFORMAT and TT2$M_PASTHRU are basically the same.
>>>
>>> So, is it the TT driver, or tcp, or something else converting the LF to
>>> CRLF?
>>
>> While I cannot answer, I should repeat what I pointed out before. The
>> "telnet" protocol is really just a TCP stream, with a couple of things
>> thrown in.
>
> You can use TNA ports/devices without using the telnet protocol.
> Just use /prot=none.

Do you have any specific information what that implies? The normal 
behavior under Unix is that if you talk on a different port than 23, the 
telnet negotiation is not performed. For many, this is the "telnet 
protocol". The special interpretation of 0xff as well as the NVT 
handling is still in effect. But that is under Unix. So I'm curious if 
the *exact* behavior of that switch under VMS is documented.

Any way, tcpdump is still an excellent tool to start finding out what is 
happening where.

(I guess my point being that the "telnet protocol" is a very unclear 
thing to start with.)

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
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