`
`/-/o -a3ry
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`IN THE IJNITED STATES PATENT AND TRADEMARK OFFICE
`
`An Unit 2665
`Examiner Phuongchau Ba Nguyen
`
`In Re:
`Case:
`Serial No.:
`Filed:
`Subject:
`
`Deepak Mansharamani et al.
`P4506
`09/800,678
`March 6,2001
`An Improved System for Fabric Packet Control
`
`To: The Commissioner of Patents and Trademarks
`Washington, D.C. 20231
`
`Dear Sir:
`
`Response B
`
`All of the claims standing for examination are presented below in their last-
`amended form. Those claims herein amended in the present response are marked
`
`(Amended). Those claims left unchanged are marked (Unchanged).
`
`"fi
`/t
`
`wice Amended) A method for managing data traffic at switching element
`
`nodes i
`
`ic network, each switching element node having a plurality of input
`
`and output
`
`ising the steps of:
`
`(a) establi
`
`each input port, a number of virtual output queues equal
`
`to the number of output po
`
`virtual output queue at each individual input
`
`port dedicated to an individual
`
`port, storing only packets destined for the
`
`ing data traffic; and
`associated output port, for managing i
`(b) accepting or discarding data at each\ual output queue directed to a
`ive to queue capacity by
`queue according to the quantity of data in the queue
`
`providing a queue manager for monitoring quantity of queu
`
`preset threshold, and discarding data at a predetermined rate when
`
`in relation to a
`iw of
`
`Juniper Exhibit 1008
`
`
`
`queued data reaches the threshold.
`
`-2-
`
`(Unchanged) The method of claim 1 wherein, in step (b), all data is discarded
`for\ full queue.
`
`Cancel
`
`laim 3.
`
`b7
`
`4. (Once
`
`The method of claim 1 wherein in step C, the queue manager
`
`increases the
`
`of discarding as quantity of queued data increases above the
`
`preset threshold,
`
`ing all data traffic when the queue is full.
`
`^2b)
`
`5. (Twice Amended)\ switching element node for a fabric network, comprising:
`a plurality of in\ut and output ports;
`
`a number of vi
`
`output queues at each input port equal to the number
`
`of output ports, each virrual\utput queue at each individual input port dedicated
`to an individual output port, s\ing only packets destined for the associated
`data traffic; and
`output port , for managing i
`characteized in that the q
`
`manager accepts or discards data directed
`
`to a queue according to the quantity o\data in the queue relative to queue capacity
`
`by monitoring quantity of queued data a\ainst a preset threshold, and randomly
`
`discarding data when the quantity of q
`
`data exceeds the threshold.
`
`6. (Unchanged) The switching element of clai
`
`5 wherein all data is discarded for
`
`a full queue.
`
`Cancel claim 7.
`
`8. (Unchanged) The switching element of claim 7
`increases the rate of discarding as the quantity of
`
`n the queue manager
`increases above thi
`
`preset threshold.
`
`
`
`-3-
`
`9. (Twice
`
`) A data router having external connections to other data
`
`routers,
`
`smg:
`
`anl
`
`I fabric network; and
`
`a plural
`
`of switching element nodes in the intemal fabric network, each
`
`switchine elem
`
`node having a plurality of input and output ports, and at each
`
`lnput port, a num r of virnral output queues equal to the number of output ports,
`
`each virtual output ueue at each individual input port dedicated to an individual
`ly packets destined for the associated output port, for
`
`output port, storing
`
`managing incoming
`
`traffic;
`
`characterized
`
`t the queue manager accepts or discards data directed
`
`to a queue according to
`
`quantity of data in the queue relative to queue capacity
`
`by monitoring the quanti
`
`ofqueued data against a preset threshold, and begins
`
`to randomly discard data w
`
`the quantity of queued data exceeds the threshold.
`
`10. (Unchanged) The data rou
`
`of claim 9 wherein all data is discarded for a full
`
`queue.
`
`'1-
`Cancel claim 11.
`
`b{
`
`12. (Once Amended) The data router
`
`claim 9 wherein the queue manager
`
`increases the rate of discarding as the
`
`ity of queued data increases above the
`
`oreset threshold.
`
`
`
`-4-
`
`REMARKS
`
`The present amendment is responsive to the Office Action mailed in the
`above-referenced case on September 10,2002, made final. Claims 1-12 are
`presented for examination. The Examiner rejects claims 1-2 under 35 U.S.C.
`102(b) as being anticipated by Khacherian (US 5,768,257)herein Khacherian.
`In response to the Examiner's rejection applicant herein amends the claims
`rya'1r,,3ger accepts or discards data directed to a
`to positively recite that the queue
`queue according to the quantity of data in the queue relative to queue capacity by
`monitoring the quantity of queued data against a preset threshold, and begins to
`randomly discard data when the quantity of queued data exceeds the threshold.
`Claims 3,7 , and I I are herein cancelled as their limitations have been added to
`their respective base claims by amendment.
`Regarding claims 3,7 and 11, the Examiner states that Khacherian
`discloses that the queue manager (316,326,Fig. 3) monitors quantity of queued
`data against a preset threshold, and begins to randomly discard data when the
`quantity of queued data exceeds the threshold (col. 1, lines 48-51, 55-63).
`Applicant respectfully traverses the Examiner's interpretation of
`Khacherian. Applicant's claimed limitation specifically recites that the queue
`manager monitors quantity of queued data in relation to a preset threshold, and
`begins to discard data at a predetermined rate when the quantity of queued data
`reaches the threshold. Applicant points out that randomly discarding data, and
`
`discarding data at a predetermined rate do not read on each other.
`The portions of Khacherian (col. 1, lines 48-51, and 55-63), relied upon by
`the Examiner, specifically teach that even with buffer control it is sometimes
`necessary to drop cells. For instance, when cells come in on input ports I and2,
`all destined for output 3, it is often the situation that more cells come in than can
`be output at output port 3. The cells begin to get queued up in the buffers. If this
`
`
`
`-f,-
`
`situation continues long enough, the buffers get filled up, and cells need to be
`
`"dropped".
`Khacherian continues to teach that prior solutions to buffer control fall
`
`into two basic categories: 1) input buffering with output control; 2) output
`
`buffering with output control. Khacherian teaches that input buffers are
`
`advantageous because smaller buffers are used and cells do not get transferred .
`
`across the network fabric.
`
`Applicant argues that said claimed limitations in applicant's invention are
`
`much more limiting than the broad demonstration of buffering described by
`
`Khacherian. There is no disclosure in Khacherian of monitoring queue capacity
`against a pre-set threshold. Khacherian drops cells when buffers are full.
`Khacherian teaches that cells begin to get queued up in the,buffers. If this
`
`siruation continues long enough, the buffers get filled up, and cells need to be
`
`"dropped".
`
`Applicant's claimed method of monitoring queues, establishing preset
`
`thresholds for the queues, and discarding at a predetermined rate according to the
`
`preset thresholds are not taught in the art of Khacherian.
`
`The main advantage of applicant's invention over the art is that each queue
`manager of applicant's invention has an ability to legin to drop packets at a pre-
`determined rcte atsome threshold in queue capacity short of a full queue. In
`
`certain further embodiments the queue manager may accelerate the rate of packet
`dropping as a queue continues to fill above the first threshold. In these instanses
`
`the incidence of dropping packets is minimized and managed, and spread over
`more traffic than would be the case if dropping of packets were to begin only at a
`full queue, wherein all packets would be dropped until the queue were to begin to
`
`empty.
`
`Another distinct advantage of the queue management scheme of the
`
`present invention is that the intelligence required is considerably lessened, and
`
`there is no addition to the traffic load by generating Flow Control indicators.
`Applicant believes claims 1, 5 and 9 are patentable over the art of
`
`
`
`-6-
`
`Khacherian, as amended and argued. Depended claims 2,4,6,8, 10 and 12 are
`
`patentable on their own merits, or at least as depended upon a patentable claim.
`
`In view of the above arguments and amendments to the claims, it is clear
`
`that the reference provided by the Examiner does not anticipate or suggest the
`
`invention as herein claimed. It is therefore respectfully requested that this
`
`application be reconsidered, the claims be allowed, and that this case be passed
`
`quickly to issue.
`
`If there are any time extensions needed beyond any extension specifically
`requested with this amendment, such extension of time is hereby requested. If there
`
`are any fees due beyond any fees paid with this amendment, authorizatron is given
`
`to deduct such fees from deposit account 50-0534.
`
`
`
`-7-
`
`Version With Markings to Show Changes Made
`
`In the claims.
`
`1. (Twice Amended) A method for managing data traffic at switching element
`nodes in a fabric network, each switching element node having a plurality of input
`
`and output ports, comprising the steps of:
`
`(a) establishing at each input port, anumber of virtual output queues equal
`to the number of output ports, each virtual output queue at each individual input
`port dedicated to an individual output port, storing only packets destined for the
`associated output port, for managing incoming data traffic; and
`(b) accepting or discarding data at each virtual output queue directed to a
`queue according to the quantity of data in the queue relative to queue capacity !y
`providing a queue manager for monitoring quantitv of queued data in relation to a
`preset threshold, and discarding data at a predetermined rate when the quantitv of
`
`queued data reaches the threshold.
`
`Cancel claim 3.
`
`4. (Once Amended) The method of claim [3] 1 wherein in step C, the queue
`manager increases the rate of discarding as quantity of queued data increases
`above the preset threshold, discarding all data traffic when the queue is full.
`
`5. (Twice Amended) A switching element node for a fabric network, comprising:
`a plurality of input and output ports; [and]
`a number of virnral output queues at each input port equal to the number
`of output ports, each virtual output queue at each individual input port dedicated
`to an individual output port, storing only packets destined for the associated
`output port , for managing incoming data traffrc; and
`characterized in that the queue manager accepts or discards data directed
`
`
`
`-8-
`
`to a queue according to the quantity of data in the queue relative to queue capacity
`
`by monitoring quantity of queued data against a preset threshold, and randomly
`
`discarding data when the quantity of queued data exceeds the threshold.
`
`Cancel claimT.
`
`9. (Twice Amended) A data router having extemal connections to other data
`
`routers, comprising:
`
`an internal fabric network; and
`
`a plurality of switching element nodes in the internal fabric network, each
`
`switching element node having a plurality of input and output ports, and at each
`
`input port, a number of virtual output queues equal. to qhe number of output ports,
`
`each virtual output queue at each individual input port dedicated to an individual
`
`output port, storing only packets destined for the associated output port, for
`
`managing incoming data traffic;
`
`characterized in that the queue manager accepts or discards data directed
`
`to a queue according to the quantity of data in the queue relative to queue capacity
`bv monitoring the quantitv of queued data against a Dreset tlrreshold, and begins
`to randomly discard data when the quantity of queued data exceeds the threshold.
`
`Cancel claim I 1.
`
`12. (Once Amended) The data router of claim tl1l 2 wherein the queue manager
`increases the rate of discarding as the quantity of queued data increases above the
`
`preset threshold.
`
`
`
`-9-
`
`Respectfully submitted
`
`Deepak Mansharamani et al.
`
`Reg. No. 35,074
`
`Donald R. Boys
`Central Coast Patent Agency
`P.O. Box 187
`Aromas, CA 95004
`(83r) 726-r4s7
`
`