[ale] OT re. serial pinouts

[Scott Denlinger]

Hi everyone,

I'm trying to make a management cable for my Cisco uBR904 cable modem, since it
didn't come with one when I bought it, and I'm wondering if anyone can help me
with the pin-outs. Like other Cisco management cables, it's a serial cable with
RJ-45 on the modem end, and serial (DE-9) on the computer end.

In general I know you need to cross the TX and REC pins for serial
connections, but do you need to do the same for DTR and DSR? Or does DSR on the
cable modem connect to DSR on the computer's serial port, and DTR go to DTR?
Should my pinouts go like this:

  modem     computer
  TX   ---> REC
  REC  ---> TX
  DTR  ---> DTR
  DSR  ---> DSR

or like this:

  modem      computer
  TX   --->  REC
  REC  --->  TX
  DTR  --->  DSR
  DSR  --->  DTR

(note that I'm not necessarily indicating signal direction in the above, just
connections)

Thanks.

Scott Denlinger
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