Cisco Systems CISCO7201 Manual De Usuario

Examine the sequence of colored wires to determine the type of cable, as follows:

Straight-through—The colored wires are in the same sequence at both ends of the cable.

Crossover—The first (far left) colored wire at one end of the cable is the third colored wire at the 
other end of the cable.

You can identify a crossover cable by comparing the two modular ends of the cable. Holding the cables 
in your hand, side-by-side, with the tab at the back, the wire connected to the pin on the outside of the 
left connector (pin 1) should be the same color as the pin on the outside of the right connector (pin 8).

 provides information about asynchronous device cabling options.

Flow control is not configurable. The information in this section explains some of the parameters of flow 
control.

GE port 0/3:

When the Cisco 7201 GE 0/3 port is set to no negotiation auto, it does not advertise anything in 
regard to flow control. The Cisco 7201 GE 0/3 port responds to pause frames if the other side makes 
the request, but will not send pause frames. 

When the Cisco 7201 GE 0/3 port is set to negotiation auto, flow control is enabled, which means 
the peer accepts symmetrical or asymmetical flow control, and sends pause frames. If the peer does 
not accept flow control requests, the Cisco 7201 router does not send pause frames. (The Cisco 7201 
router always accepts pause frames, whether in fixed mode or auto mode.)

GE ports 0/0, 0/1, and 0/2:

 

These interfaces function the same as above with the exception that there will never be a pause request 
transmitted regardless of mode. 

H5663

Crossover

RJ-45-to-DB-25M

Terminal or DTE

Crossover

RJ-45-to-DB-9M

Terminal or DTE

Straight-through

RJ-45-to-DB-25F

Modem or DCE