HP (Hewlett-Packard) 100BASE-TX Manuel D’Utilisation
14
Chapter 1
Installing and Configuring PCI 10/100 Base-TX
Autonegotiation and Autosensing
Autonegotiation and Autosensing
Autonegotiation is a mechanism defined in the IEEE 802.3u specification
whereby devices sharing a link segment can exchange information and
automatically configure themselves to operate at the highest capability
mode shared between them.
whereby devices sharing a link segment can exchange information and
automatically configure themselves to operate at the highest capability
mode shared between them.
Autonegotiation is like a rotary switch that automatically switches to the
correct technology such as 10Base-T or 100Base-TX or between half- and
full-duplex modes. Once the highest performance common mode is
determined, auto-negotiation passes control of the link to the
appropriate technology, sets the appropriate duplex mode, and then
becomes transparent until the link is broken.
correct technology such as 10Base-T or 100Base-TX or between half- and
full-duplex modes. Once the highest performance common mode is
determined, auto-negotiation passes control of the link to the
appropriate technology, sets the appropriate duplex mode, and then
becomes transparent until the link is broken.
Following is the IEEE 802.3u-defined hierarchy for resolving multiple
common abilities for a 10/100Base-TX card. The PCI
10/100Base-TX/9000 ports provide the means for interfacing various
types of HP 9000 workstations and servers to either a 10Base-T or
100Base-TX network. 100Base-TX is a subset of 100Base-T networking
defined by the IEEE 802.3u-1995 standard. 100Base-TX provides 100
Mbit/s data transmission over category 5 unshielded twisted-par (UTP)
cable. Two pairs of wires in the cable are used—one wire pair is for
receiving data, and one wire pair is for transmitting data. The same card
port that supports 100Base-TX operation can also support 10Base-T
operation.
common abilities for a 10/100Base-TX card. The PCI
10/100Base-TX/9000 ports provide the means for interfacing various
types of HP 9000 workstations and servers to either a 10Base-T or
100Base-TX network. 100Base-TX is a subset of 100Base-T networking
defined by the IEEE 802.3u-1995 standard. 100Base-TX provides 100
Mbit/s data transmission over category 5 unshielded twisted-par (UTP)
cable. Two pairs of wires in the cable are used—one wire pair is for
receiving data, and one wire pair is for transmitting data. The same card
port that supports 100Base-TX operation can also support 10Base-T
operation.
• 100Base-TX full-duplex
• 100Base-TX half-duplex
• 10Base-T full-duplex
• 10Base-T half-duplex
For example, if both devices on the link support 10Base-T (half-duplex)
and 100Base-TX (half-duplex), autonegotiation at both ends will connect
the 100Base-TX (half-duplex) instead of the 10Base-T (half-duplex).
and 100Base-TX (half-duplex), autonegotiation at both ends will connect
the 100Base-TX (half-duplex) instead of the 10Base-T (half-duplex).
Most Fast Ethernet devices on the market today such as hubs and
switches do not support autonegotiation. Either the speed and duplex
mode of the device are fixed (as is usually the case with hubs), or they are
often manually configured at the desired speed and duplex (as is often
the case for switches). However, switches that support autonegotiation
are starting to be offered.
switches do not support autonegotiation. Either the speed and duplex
mode of the device are fixed (as is usually the case with hubs), or they are
often manually configured at the desired speed and duplex (as is often
the case for switches). However, switches that support autonegotiation
are starting to be offered.