Appendix A Specifications
Gigabit Ethernet Flow Control Information
Figure A-5 Identifying a Crossover or Straight-Through Cable
H5663
Examine the sequence of colored wires to determine the type of cable, as follows:
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You can identify a crossover cable by comparing the two modular ends of the cable. Holding the cables in your hand,
Table
Table | Asynchronous Device Cabling Options |
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Cable |
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Crossover |
| Terminal or DTE | |
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Crossover |
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Modem or DCE | |||
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Gigabit Ethernet Flow Control Information
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.
Cisco 7201 Installation and Configuration Guide
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