10BASE-T
is a variety of network protocol Ethernet collected in the review IEEE 802.3i in 1990 that defines the connection using twisted pair cable. Used for short distances due to its low cost. Each twisted-pair cable contains 4 pairs of cables. In each pair are twisted together a colored wire and a white wire marked with the same color. The commonly used colors are orange, green, blue and brown. This cable is capable of transmitting at 10Mbps .
The standard usually adopted for connectors RJ45 of these cables is BN-N-BV-A-BA-V-BM-M at both ends. This requires that there be a switch ( hub or switch ) between the machines involved in the connection. For a direct connection between two machines, you must use a crossover cable , instead of connecting wire to wire signals cross each other RX and TX changing greens and oranges.
is noteworthy that these cables are only used green and orange, so you can see there are cases where two lines pass through the same Ethernet cable with two connectors at each end, or line Ethernet and ISDN . Also, some people are using laptops to your network connection, a cable with a connector pair "direct" and another crusade. This would be done (for example) as follows:
End 1 Connector 1
BN-N-BV-2 connector
OoVoo
BM-M-BA-OOAOO
End 2 Connector 1
BN-N-BV- Connector 2
OoVoo BA-A-BM-OOMOO
marking the connectors 2 at each end with red tape or red marker to recognize as a crossover cable.
General Networks LAN are more common today. This system alleviates the defects known networks 10Base2 and 10Base5 , including incorrect detection of unwanted derivations of breaks and loose connectors. A major disadvantage is the facility connected by hubs which can be expensive and quite complicated for large networks. However, one of the big advantages is the possibility of connecting new components to the network as is used by other computers without having to restart. Physical environment
From your 10BASE-T name is extracted several characteristics of this medium, 10 indicates the transmission speed Megabits per second (Mb / s) , BASE is short for band base and T to use twisted pair cables . Specifically, the cable used, UTP Category 3 (25 MHz in lengths of 100 m), consists of four twisted pairs without screening, of which at least one pair is used for transmission and another for reception.
The maximum length of the collision domain (with repeaters) reaches up to 2500 m using a coaxial backbone and the maximum number of stations in the collision domain is 1024 accepted. The cable is connected via a connector RJ-45 to network card in the PC . Each station is connected to a hub or concentrator central topology following a star or extended star, but functions as a logical bus. There hubs with different configurations, with 4, 8, 12, 15 or 24 RJ-45 ports, and even the possibility of connecting cable Ethernet type 10Base2 or others.
Signage
simpler signal used is the NRZL (nonreturn to Zero Level), the signal returns to 0 and the voltage pulse has a duration of 1 bit. Usually a logical 1 voltage is a pulse while a logical 0 is the absence of the voltage pulse.
can not send data with a trigger signal. The receiver synchronizes through transitions of pulses received. But if you have a long sequence of zeros or ones, the signal remains constant over a long enough time line and the receiver can not identify the beginning and end of each bit, this problem is solved by encryption.
signal coding can be: unipolar in which the 1s can have positive or negative polarity and 0s none. Polar whose signal will be positive to negative values \u200b\u200b1 and 0 values, and bipolar, that alternating polarity digit and the other is always on.
cable morphology
A 10BASE-T node, such as a computer, communicate sending to pins 1 and 2, and will receive 3 to 6, as opposed to make the switch or hub that is connected, you will receive on pins 1 and 2, and output from the 3 and 6 . To connect two computers directly with each other will need to use a crossover cable .
The correct connection of these cables must be according to the following table:
0 comments:
Post a Comment