Cisco – What’s the difference between Serial DCE and Serial DTE link

ciscopacket-tracer

In the Cisco Packet Tracer we also see the Serial DCE and Serial DTE:

enter image description here

but I don't know what's the difference between them.

Best Answer

One side of the link (DCE), has to transmit the clock signal, which controls the data rate, and the other side (DTE) receives the clock signal.

R1 is DCE here:

interface Serial0/0/0
 ip address 10.0.0.1 255.255.255.252
 clock rate 2000000

R2 is DTE here:

interface Serial0/0/0
 ip address 10.0.0.2 255.255.255.252

The difference between the two cables in packet tracer is just which side you click first:

enter image description here

  • With the DCE cable, (red zigzag with clock) the side you click first will be the DCE, the second will be DTE
  • With the DTE cable (red zigzag no clock) the side you click first will be DTE, the second will be DCE

Whichever way you do it, you'll see one side of the cable shows the clock symbol: this is the DCE.