US5889778A — ATM layer device

Claim 1

Independent Claim 112 words

An ATM layer device for interfacing between physical layer devices and an ATM switch, said ATM layer device comprising: (a) a single input cell interface couplable to a plurality of said physical layer devices in an ingress mode and to an output of said ATM switch in an egress mode; (b) an output cell interface couplable in an ingress mode to an input of said ATM switch and in an egress mode to said physical layer devices. wherein, in an ingress mode of operation, said input cell interface selects among the physical layer devices a physical layer device for cell transmission based upon the availability of cells from said physical layer devices.

Claim 2

Dependent Claim 112 words

An ATM layer device for interfacing between physical layer devices and an ATM switch, said ATM layer device comprising: (a) a single input cell interface couplable to a plurality of said physical layer devices in an ingress mode and to an output of said ATM switch in an egress mode; (b) an output cell interface couplable in an ingress mode to an input of said ATM switch and in an egress mode to said physical layer devices. wherein, in an ingress mode of operation, said input cell interface selects among the physical layer devices a physical layer device for cell transmission based upon the availability of cells from said physical layer devices.

Claim 3

Dependent Claim 47 words

A device according to claim 1, wherein said input cell interface is couplable, in an ingress mode, to said plurality of physical layer devices by a bus and said output interface is couplable, in an egress mode, to a plurality of physical layer devices by a bus.

Claim 4

Dependent Claim 41 words

A device according to claim 1, wherein, in an ingress mode of operation, said input cell interface selects among the physical layer devices a physical layer device for cell transmission based upon the availability of cells from said physical layer devices.

Claim 5

Dependent Claim 47 words

A device according to claim 1, including means for prepending and postpending of switch routing information to cells destined to enter said switch and for removing such information from cells having left said switch and means for selectively activating and deactivating said means for prepending and postpending.

Claim 6

Dependent Claim 16 words

A device according to claim 1, including a cell buffer coupled to said input cell interface.

Claim 7

Dependent Claim 18 words

A device according to claim 5, including an external RAM address look-up operative to look up cell addresses.

Claim 8

Dependent Claim 40 words

A device according to claim 2, wherein said output cell interface, when in an ingress mode, informs the ATM switch if it has a cell available for transfer and waits for the ATM switch to authorize transfer of the cell.

Claim 9

Dependent Claim 84 words

A device according to claim 1, wherein cells from a switch destined to a particular physical layer device are treated independently from any other cells destined to other physical layer devices, when said device is in a transparent egress mode, such that buffer space in said ATM layer device is split up among physical physical layer devices and for each physical layer device, it is determined if space is available and, if so, the ATM switch authorizes cell transfer to that physical layer device.

Claim 10

Dependent Claim 47 words

A device according to claim 2, wherein said output cell interface is couplable to a plurality of physical layer devices and said output cell interface selects between the plurality of physical layer devices based upon transmit buffer space available when said device is in an egress mode.

Claim 11

Dependent Claim 56 words

A device according to claim 1, including a cell processor and external ram address look-up for accessing an entry from a plurality of entries in a VC table based upon cell header information and a physical layer device address, said entry and said address used in combination to identify each received cell of said ATM cells.

Claim 12

Dependent Claim 33 words

A device according to claim 1, including a cell processor and external ram address look-up for accessing VPI/VCI translation tables contained in VC table entries of a VC table for translating cell headers.

Claim 13

Dependent Claim 33 words

A device according to claim 1, including a cell processor and external ram address look-up for accessing VPI/VCI policing information contained in table entries of a VC table for policing virtual channel specifications.

Claim 14

Dependent Claim 31 words

A device according to claim 1, including a cell processor and external ram address look-up for accessing VPI/VCI performance information contained in table entries of a VC table for monitoring performance.

Claim 15

Dependent Claim 38 words

A device according to claim 2, including an auxiliary cell interface and auxiliary cell FIFO buffer operative to provide a byte wide UTOPIA bus port and pass dropped or newly created cells to and from an external device.

Claim 16

Dependent Claim 33 words

A device according to claim 4, physical layer device address information is taken from a portion of the ATM layer device which controls which physical layer device from which to transfer a cell.

Claim 17

Independent Claim 125 words

A method for interfacing between physical layer devices and an ATM switch, comprising: (a) in an ingress mode, transferring cells in sequence on a shared bus from a plurality of physical layer devices to an input cell interface of an ATM layer device each cell transfer from said physical layer devices being controlled by said ATM layer based upon the availability of cells from said physical layer devices; (b) passing said cells uni-directionally through said ATM layer device; (c) processing said cells in sequence as they arrive; and (d) outputting said cells after processing from an output cell interface of said ATM layer device to said ATM switch; wherein a shared bus input couples said input cell interface to said plurality of physical layer devices.

Claim 18

Independent Claim 125 words

A method for interfacing between physical layer devices and an ATM switch, comprising: (a) in an ingress mode, transferring cells in sequence on a shared bus from a plurality of physical layer devices to an input cell interface of an ATM layer device each cell transfer from said physical layer devices being controlled by said ATM layer based upon the availability of cells from said physical layer devices; (b) passing said cells uni-directionally through said ATM layer device; (c) processing said cells in sequence as they arrive; and (d) outputting said cells after processing from an output cell interface of said ATM layer device to said ATM switch; wherein a shared bus input couples said input cell interface to said plurality of physical layer devices.

Claim 19

Dependent Claim 32 words

A method according to claim 16, including prepending and postpending switch routing information to cells destined to enter said ATM switch and removing such information from cells having left said ATM switch.

Claim 20

Dependent Claim 16 words

A method according to claim 17, including selectively activating and deactivating the cell prepending and postpending.

Claim 21

Dependent Claim 53 words

A method according to claim 16, including simultaneously transferring a cell from the input cell interface to a 4 cell buffer, transferring a cell header and appended bytes from the 4 cell buffer to an external RAM address look-up, and performing a time-interleaved address look-up for more than one cell at a time.

Claim 22

Dependent Claim 39 words

A method according to claim 16, including, when in an ingress mode, informing the switch core if it has a cell available for transfer and transferring an available cell upon receipt of authorization being received from said switch core.

Claim 23

Dependent Claim 46 words

A method according to claim 16, wherein, in a transparent egress mode, allocating buffer space in said ATM layer device among physical layer devices and, for each physical layer device, determining if space is available and, if so, authorizing cell transfer to that physical layer device.

Claim 24

Dependent Claim 44 words

A method according to claim 16, wherein said output cell interface is couplable to a plurality of physical layer devices and an output cell interface selects between the plurality of physical layer devices based upon transmit buffer space available when in an egress mode.

Claim 25

Dependent Claim 24 words

A method according to claim 16, including translating cell headers by accessing VPI/VCI translation tables contained in VC table entries of a VC table.

Claim 26

Dependent Claim 33 words

A method according to claim 16, including policing virtual channel specifications utilizing a cell processor and external ram address look-up for accessing VPI/VCI policing information contained in table entries of a VC table.

Claim 27

Dependent Claim 32 words

A method according to claim 16, including monitoring performance which includes a cell processor and external ram address look-up for accessing VPI/VCI performance information contained in table entries of a VC table.

Claim 28

Dependent Claim 28 words

A method according to claim 16, including prepending and postpending physical layer device identification information and combining this identification information with VPI/VCI values when cell identification is made.

Claim 29

Dependent Claim 25 words

A device according to claim 6, wherein said cell addresses are looked up simultaneously for three cells at a time on a time interleaved basis.

Claim 30

Dependent Claim 147 words

An ATM switching system which includes an ATM switch, a plurality of physical layer devices and a pair of ATM layer devices each having an input and an output interface, an ingress ATM layer device interfacing between said physical layer devices and said ATM switch in an ingress mode and an egress ATM layer device interfacing between said physical layer devices and said ATM switch in an egress mode, comprising: (a) a shared input bus coupling said plurality of physical layer devices to said input interface of said ingress ATM layer device; (b) a shared output bus coupling said output interface of said egress ATM layer device and said plurality of physical layer devices; wherein said ingress ATM layer device selects among said plurality of physical layer devices physical layer device for cell transmission based upon the availability of cells from said plurality of physical layer devices.

Claim 31

Dependent Claim 147 words

An ATM switching system which includes an ATM switch, a plurality of physical layer devices and a pair of ATM layer devices each having an input and an output interface, an ingress ATM layer device interfacing between said physical layer devices and said ATM switch in an ingress mode and an egress ATM layer device interfacing between said physical layer devices and said ATM switch in an egress mode, comprising: (a) a shared input bus coupling said plurality of physical layer devices to said input interface of said ingress ATM layer device; (b) a shared output bus coupling said output interface of said egress ATM layer device and said plurality of physical layer devices; wherein said ingress ATM layer device selects among said plurality of physical layer devices physical layer device for cell transmission based upon the availability of cells from said plurality of physical layer devices.

Claim 32

Dependent Claim 112 words

A system according to claim 28, including buffer memory coupled to said input cell interface of each of said ingress and egress ATM layer devices and said engress ATM layer device, in a routing mode, accepts all cells from said ATM switch and, in a transparent mode, apportions internal buffer memory space to each of said plurality of physical layer devices and determines independently for each of said physical layer devices if buffer space is available and, if available, informs said ATM switch which authorizes cell transfer from physical layer devices of said plurality of physical layer devices having cells available for transfer and ATM layer device internal buffer memory space available.

Claim 33

Dependent Claim 39 words

A system according to claim 28, wherein cell identification in said ingress ATM layer device is based upon a combination of VPI/VCI values and information as to which of said plurality of physical layer devices a cell was transmitted.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2002-03-29	2002-09-28	2003-03-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2006-03-29	2006-09-28	2007-03-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2010-03-29	2010-09-28	2011-03-30	$7700.00	Window Closed / Lapsed

ATM layer device

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