ARDUINO & DD-WRT

Using Arduino Networking, Protocols, and Devices
2

ok I did the following:

I run this in arduino:

void setup(){
 Serial.write("Hi, I am alive!");
 }
 void loop(){
 }

and then I SSH to my Router and type in:

cat < /dev/cua/1 and I get : -sh: can't open /dev/cua/1: no such file

and also tried this:

cat < /dev/tty.usbserial-A9007VSI and I get : -sh: can't open /dev/tty.usbserial-A9007VSI: no such file

I saw this post here which was helpful but still I can't tx-rx between arduino and my router:
http://forum.arduino.cc/index.php/topic,39610.0.html
can somebody please explain. Thanks!