[Ltsp-discuss] Re: Serial port redirection

[Jeffrey Altman]

The reality is RFC is experimental and not authoritative. The only thing that really counts is what Cisco actually shipped in their IOS implementation. Lucky me I actually have a terminal
server that implements it. If you look at the C-Kermit sources you will see that the client is written to accept both values from the server. You will also find that Cisco does not send the baudrates as specified in the RFC but instead uses an enumeration.

With regards to the comment about the use of separate codes to indicate direction, this was written without a good understanding of the Telnet Option negotiation. The reality is that there is no need for a telnet protocol option to have separate commands for each direction as the option itself must be negotiated separately in each direction. Therefore, there is no possibility of confusion.

Jeffrey Altman




Corey Minyard wrote:

Jeffrey Altman wrote:

Peter Astrand wrote:

* ser2net is totally incompatible with cyclades-serial-client. This is
because ser2net interprets RFC2217 a bit differently. sredird sends
command "101" as ack for command "1", while ser2net sends "1". RFC2217 is
not very explicit about which way is most correct. The ser2net approach
looks better to me, but the sredird one is probably more widely used
(since Cyclades terminal server uses it, for example.) Probably, RFC2217
software needs to handle both cases.

ser2net is wrong

Umm, no. Cyclades and sredird are wrong. And it's pretty clear. From RFC2217:

Client to Access Server Access Server to Client
SIGNATURE text text
SET-BAUDRATE 1 101
SET-DATASIZE 2 102
SET-PARITY 3 103
SET-STOPSIZE 4 104
SET-CONTROL 5 105
NOTIFY-LINESTATE 6 106
NOTIFY-MODEMSTATE 7 107
FLOWCONTROL-SUSPEND 8 108
FLOWCONTROL-RESUME 9 109
SET-LINESTATE-MASK 10 110
SET-MODEMSTATE-MASK 11 111
PURGE-DATA 12 112
Discussion: As initially proposed, com port configuration
commands are only sent from the client to the access
server. There is no current vision that the access
server would initiate the use of a com port configuration
command, only the notify commands. However, to allow for
access server initiated com port configurations different
command values have been established.

That last sentence of the discussion says it. The 1xx commands are there to allow the access server to *initiate* com port configuration changes. Not to ack the changes. Unless you can point me to something in the manual to say that I am wrong.

I am willing to change this in the spirit of keeping things consistent, though.

-Corey

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