High-speed data interface for connecting network devices
An interface adapted for high speed data transmission between network elements that decreases signal interference and cross-talk between the wires of a cable used for connecting the network elements. Various connection schemes are used for shielded pairs of wires within a cable used for the interface. The connection schemes may use pins having same or different pin numbers at the two network elements being connected. Shielded pairs carrying data in a common direction may be connected to adjacent sets of pins or to non-adjacent sets of pins. Certain pins at each element may remain unused. Pairs of the shielded pairs within the cable may be cross-connected between the two elements. Shielded pairs may be cross-connected while leaving sets of pins unused.
1. A bidirectional coupling for data transmission between two frame-based network devices, the coupling comprising:
a cable; and
a first cable connector coupled to a first end of the cable and a second cable connector coupled to a second end of the cable, the cable connectors each configured for coupling to a network device;
wherein the cable includes wires, the wires including at least two differential pairs of wires, each differential pair of wires comprising at least two wires, wires in a first one of the differential pairs providing a transmission path between the network devices and wires in a second one of the differential pairs providing a reverse transmission path between the network devices;
wherein each of the cable connectors includes a plurality of conductive pins each electrically coupled to a corresponding wire of the wires, the pins being arranged along a first row and a second row, the second row parallel to the first row; and
wherein at least two wires in each of the differential pairs are coupled to two adjacent pins along one of the first row or the second row.
2. The bidirectional coupling of claim 1 , wherein at least two wires in at least one of the differential pairs are bundled with a shield wire to form a shielded pair.
3. The bidirectional coupling of claim 1 wherein each cable connector comprises:
a housing having a floor, a ceiling, a pair of side walls and a rear wall, the floor and the ceiling being coupled together at opposing side margins by the pair of side walls, the rear wall having an aperture; and
the conductive pins located substantially within the housing, the conductive pins having forward ends and rear ends, the rear ends electrically connected to the wires within the cable.
4. The bidirectional coupling of claim 3 , wherein the aperture is bounded by a cylindrical guide configured to receive a cable that is substantially circular in cross-section.
5. The bidirectional coupling of claim 3 , wherein the conductive pins are located entirely within the housing.
6. The bidirectional coupling of claim 3 ,
wherein a first row includes more pins than a second row;
wherein the pins in each row are offset from the pins in the other row; and
wherein the forward ends of the pins are configured for sandwiching a plate or a substrate.
7. The bidirectional coupling of claim 3 , wherein a forward end of a one of the pins is recessed as compared to forward ends of other pins.
8. The bidirectional coupling of claim 6 , wherein the cable includes four shielded pairs; and
wherein each of the cable connectors includes nineteen conductive pins.
9. The bidirectional coupling of claim 6 , wherein the cable includes eight shielded pairs; and
wherein each of the cable connectors includes twenty nine conductive pins.
10. The bidirectional coupling of claim 2 , wherein for each of the cable connectors the pins of the first row are staggered with respect to the pins of the second row; and
wherein the shield wire in each of the shielded pairs is coupled to a pin of the first row or to a pin of the second row and the two wires in the differential pair are coupled to two adjacent pins of the second row or to two adjacent pins of the first row, with the pin coupled to the shield wire staggered between the two adjacent pins.
11. The bidirectional coupling of claim 10 , wherein each of the wires in each of the shielded pairs is connected to corresponding pins of the two cable connectors housing the same relative position within the cable connector.
12. The bidirectional coupling of claim 1
wherein the cable includes a first shielded pair, a second shielded pair, a third shielded pair, and a fourth shielded pair, each of the shielded pairs having a first end coupled to the pins of the first cable connector and a second end coupled to the pins of the second cable connector;
wherein the first end of the first shielded pair is coupled to the first cable connector at pins of a first group,
wherein the first end of the second shielded pair is coupled to the first cable connector at pins of a second group;
wherein the first end of the third shielded pair is coupled to the first cable connector at pins of a third group;
wherein the first end of the fourth shielded pair is coupled to the first cable connector at pins of a fourth group;
wherein each of the wires in at least two of the shielded pairs is connected to corresponding pins of the two cable connectors having different relative positions within the cable connector, whereby the at least two of the shielded pairs are cross-connected.
13. The bidirectional coupling of claim 12 , wherein the first shielded pair and the third shielded pair are cross-connected; and
wherein the second shielded pair and the fourth shielded pair are cross-connected.
14. The bidirectional coupling of claim 12 , wherein the first shielded pair and the second shielded pair are cross-connected; and
wherein the third shielded pair and the fourth shielded pair are cross-connected.
15. The bidirectional coupling of claim 12 , wherein the first shielded pair and the fourth shielded pair are cross-connected; and
wherein the second shielded pair and the third shielded pair are cross-connected.
16. A method for bidirectional data transmission between two frame-based network devices coupled together by a cable having a plurality of wires including differential pairs of wires, each of the differential pairs being bundled with a third wire for shielding thereby forming a shielded pair, the wires being coupled to each of the network devices through a cable connector, the cable connector including pins coupled to the wires, the method comprising:
transmitting data in a first direction over a first set of shielded pairs coupled to a first cable connector at a first group of pins, the pins in the first group being adjacent one another; and
transmitting data in a second direction reverse to the first direction over a second set of shielded pairs coupled to the first cable connector at a second group of pins, the pins in the second group being adjacent one another;
wherein the wires in each shielded pair are coupled to adjacent pins at each of the cable connectors.
17. The method of claim 16 , further comprising:
handshaking between the two network devices to determine a direction of data transmission over each of the shielded pairs;
wherein either the shielded pair or a fourth wire is utilized for the handshaking.
18. The method of claim 16 , further comprising, before the transmitting of data in the first direction:
inverse multiplexing the data at a first one of the network devices; and
placing inverse-multiplexed data on the first set of shielded pairs.
19. A bidirectional coupling between a pair of network devices comprising:
a plurality of shielded pairs of wires, the wires each having distal portions connected to a corresponding conductive mating element of a connector, the conductive mating elements selected from a plurality of conductive mating elements arranged in substantially parallel rows, each shielded pair of wires providing a data path between a first network device and a second network device, and at least two of the shielded pairs providing data paths in opposing directions.
20. A bidirectional data path between network devices comprising:
a first connector with a plurality of conductive mating elements arranged in two rows;
a second connector with a plurality of corresponding conductive mating elements arranged in two rows; and
a plurality of shielded pairs of wires connecting the first connector and the second connector, each wire of the shielded pairs of wires connecting non-corresponding conductive mating elements of the first connector and the second connector.
21. A network device configured for bidirectional communication with a second network device through a cable, the network device comprising:
a device connector for mating with an external cable connector and receiving input from and providing output to the cable connector, the external cable connector comprising a housing having a floor, a ceiling, a pair of side walls and a rear wall, the floor and the ceiling being coupled together at opposing side margins by the pair of side walls, the rear wall having an aperture and conductive pins located substantially within the housing, the conductive pins having forward ends and rear ends, the rear ends electrically connected to wires within the cable, the forward ends being arranged in two parallel rows;
an input processing block for processing the input received at the cable connector;
an output processing block for processing the output to the cable connector;
a switch engine coupled to the input processing block and the output processing block, the switch engine having at least one cross-switch and providing a switching function; and
a controller for controlling the switch engine;
wherein the input processing block and the output processing block perform data recovery, serialization/deserialization, signal equalization, and queuing.
22. An apparatus comprising:
a first network device;
a second network device;
a cable; and
a first cable connector coupling a first end of the cable and the first network device and a second cable connector coupling a second end of the cable and the second network device;
wherein the cable includes wires, the wires including at least two differential pairs of wires, each differential pair of wires comprising at least two wires, wires in a first one of the differential pairs providing a transmission path between the network devices and wires in a second one of the differential pairs providing a reverse transmission path between the network devices;
wherein each of the cable connectors includes a plurality of conductive pins each electrically coupled to a corresponding wire of the wires, the pins being arranged along a first row and a second row, the second row parallel to the first row; and
wherein at least two wires in each of the differential pairs are coupled to two adjacent pins along one of the first row or the second row.
23. The apparatus of claim 22 wherein the network devices are Ethernet switches.
24. The apparatus of claim 23 wherein the first Ethernet switch is configured to transmit an Ethernet frame to the second Ethernet switch over the cable, with the Ethernet frame encapsulated in a data transmission encoding format.
25. The apparatus of claim 23 wherein the second Ethernet switch is configured to transmit an Ethernet frame to the first Ethernet switch over the cable, with the Ethernet frame encapsulated in a date transmission encoding format.