[c-nsp] XMODEM transfer over telnet/ssh, any chance?

[Peter Rathlev]

Anybody know of a way to make XMODEM work over telnet/ssh? For a Sup720
stuck in ROMMON that is. I know it's almost always much faster to just
get a CF card with the right image, but this problem has me
interested. :-)

I'm connecting remotely ("reverse telnet") to the AUX port of some 1841.
The AUX port is connected to the console port of a Sup720, and this
Sup720 is placed in ROMMON. 

The connection works fine for "telnet" purposes, no problems there. But
when I try to initiate an XMODEM transfer, every block of data is
NAK'ed.

I'm using expect to connect and start the transfer, letting lszrz do the
transfer itself. The two (ROMMON/lszrz) can see each other fine. Console
initiates the transfer correctly with the first NAK after some time, but
every block that lszrz then sends is also NAK'ed.

I suspect the path isn't 8-bit clean and some kind of translation screws
things up. I just can't see why that *has* to be.

List of things I tried with no luck:

1) Read http://puck.nether.net/pipermail/cisco-nsp/2005-July/022358.html

2) Probably all combinations of Sup720 flags and lszrz flags. In my head
   it should work with "xmodem -c <file.bin>" and "sx -q <file.bin>",
   but it doesn't.

3) Many many AUX line options: "telnet transparent", "escape-character
   NONE", all to no avail.

4) Many combinations of flags for telnet, "-8", "-e ''", "-E", "-L", you
   name it...

5) SSH as transport instead of telnet.

6) Several combinations of "non default" line parameters: The Sup720
   should use 8 data bits, 1 stop bit and no parity bits.

Should I just give up? Even though this would be way cool to make
work? :-D

-- 
Peter