EP0709988A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Path allocation system and method with fairness insurance mechanism for a fiber optic switch
Assignee: McData Corp
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Filing: 1995-08-25
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Granted: —
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Expires: 2015-08-25
Abstract
Abstract A fiber optic switch (30) interconnects fiber optic channels (32) so that a fiber optic network can be implemented. Channel modules (34) provide ports (p1-pi) (33) for connection of the fiber optic channels (32). Each channel module (34) has a receive memory (84) for temporarily storing incoming data frames from the fiber optic channels (32) associated therewith. A switch module (36) having a data distribution network (42) interconnects each of the channel modules (34) and permits ultimate connection of a source channel (32) to a destination channel (32). A path allocation system (50), which controls the switch module (36), allocates the data paths between the channels (32). The path allocation system (30) has a scheduler (104) which maintains a destination queue (Q p1 -Q pi ) for each of the channels (32), a sentry (104) which determines when a new data frame (11) is ready to be routed, and an arbitrator (123) which arbitrates port availability and which grants transfer requests proposed by the scheduler (104). Significantly, the arbitrator (123) is equipped with fairness insurance mechanisms (130', 130'') for insuring that transfer requests are always timely and efficiently serviced.
Inventors
- 👤 Gregory T. Sullivan
- 👤 Robert H. Grant
- 👤 Robin Purohit
- 👤 Bent Stoevhase
- 👤 David Book
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 03:45
CPC Classifications
H; H04; H04L; H04L49/00; H04L49/35; H04L49/356; H04L49/357; H04L49/30; H04L49/3009; H04L49/351
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
340 words
A path allocation system (50) for high performance data transfer through a fiber optic switch (30) which selectively interconnects fiber optic channels (32), comprising: a plurality of ports (33) for connection to said channels (32); a memory means (84) associated with said ports (33), said memory means (84) for storing an incoming new data frame (11) from a source port (33); a distribution network (36) configured to interconnect said ports (33); a sentry (104) in communication with said memory means (84), said sentry (104) configured to determine when said new data frame (11) has been received by said memory means (84); a scheduler (118) which maintains a destination queue (121) corresponding with each of said ports (33), said scheduler (118) configured to receive path data pertaining to said new data frame (11) from said sentry (104) after said sentry (104) determines receipt of said new data frame (11), said path data including a source port indicator which identifies a source port (33) and which identifies a memory address identifying a location of said frame (11) in said memory means (84), and a destination port indicator which identifies a destination port (33), and said scheduler (118) configured to place said path data within a destination queue (121) corresponding with said destination port (33) and to retrieve said path data from said destination queue (121); an arbitrator (123) configured to control said distribution network (36) and in communication with said scheduler (118) and said ports (33), said arbitrator (123) configured to determine when said ports (33) are busy servicing other frame transfer requests and when said ports (33) are available for accommodating frame transfer requests, and said arbitrator (123) configured to deny and grant said transfer requests based upon availability; and a source fairness insurance means (130'') associated with said source port (33), said source fairness insurance means (130'') for defining an order for future access to said source port (33) as a source for data (11), said order including at least one destination port (33) corresponding to a denied transfer request.
Claim 2
Dependent Claim
30 words
The system (50) of claim 1, wherein said source fairness insurance means (130'') is a next-in-line source indicator which identifies only a single source port (33) to define said order.
Claim 3
Independent Claim
82 words
The system (50) of any of the previous claims 1 and 2, wherein said arbitrator (123) further comprises a class determination means (168) for determining whether said transfer request is directed to establishing a packet transfer and a reserved path transfer and wherein when said reserved path transfer is established, said arbitrator (123) determines (192, 193) the availability of said destination port (33) to both receive and transmit data (11) and the availability of said source port (33) to transmit data (11).
Claim 4
Independent Claim
72 words
The system (50) of any of the previous claims 1 through 3, further comprising a destination fairness insurance means (130') associated with said destination port (33), said destination fairness insurance means (130') for defining another order for future access to said destination port (33) as a destination for data (11), said another order including at least one source port (33) corresponding to another denied transfer request directed to said destination port (33).
Claim 5
Independent Claim
72 words
The system (50) of any of the previous claims 1 through 4, further comprising a destination fairness insurance means (130') associated with said source port (33), said destination fairness insurance means (130') for defining another order for future access to said source port (33) as a destination for data (11), said another order including at least one source port (33) corresponding to another denied transfer request directed to said source port (33).
Claim 6
Independent Claim
67 words
The system (50) of any of the previous claims 1 through 5, further comprising another source fairness insurance means (130'') associated with said destination port (33), said another source fairness insurance means (130'') for defining another order for future access to said destination port (33) as a source for data (11), said another order including at least one destination port (33) corresponding to a denied transfer request.
Claim 7
Independent Claim
28 words
The system (50) of any of the previous claims 1 through 6, wherein said scheduler (118) is configured to service said destination queues (121) in a sequential order.
Claim 8
Dependent Claim
340 words
A path allocation system (50) for high performance data transfer through a fiber optic switch (30) which selectively interconnects fiber optic channels (32), comprising: a plurality of ports (33) for connection to said channels (32); a memory means (98) associated with said ports (33), said memory means (98) for storing an incoming new data frame (11) from a source port (33); a distribution network (36) configured to interconnect said ports (33); a sentry (104) in communication with said memory means (98), said sentry (104) configured to determine when said new data frame (11) has been received by said memory means (98); a scheduler (118) which maintains a destination queue (121) corresponding with each of said ports (33), said scheduler (118) configured to receive path data pertaining to said new data frame (11) from said sentry (104) after said sentry (104) determines receipt of said new data frame (11), said path data including a source port indicator which identifies a source port (33) and which identifies a memory address identifying a location of said frame (11) in said memory means (98), and a destination port indicator which identifies a destination port (33), and said scheduler (118) configured to place said path data within a destination queue (121) corresponding with said destination port (33) and to retrieve said path data from said destination queue (121); an arbitrator (123) configured to control said distribution network (36) and in communication with said scheduler (118) and said ports (33), said arbitrator (123) configured to determine when said ports (33) are busy servicing other frame transfer requests and when said ports (33) are available for accommodating frame transfer requests, and said arbitrator (123) configured to deny and grant said transfer requests based upon availability; and a destination fairness insurance means (130') associated with said destination port (33), said destination fairness insurance means (130') for storing an order for future access to said destination port (33) as a destination for data (11), said order including at least one source port (33) corresponding to a denied transfer request.
Claim 9
Independent Claim
225 words
A method (130) for insuring efficient and reliable transfer of data (11) through a fiber optic switch (30) for selectively interconnecting fiber optic channels (32) which are connected to the switch (30) via respective ports (33), comprising the steps of: receiving data (11) at said switch (30) from a source port (33), said data to be switched to a destination port (33); determining when said destination port (33) is available to receive said data (11) and when said destination port (33) is busy receiving other data (11); determining when said source port (33) is available to transmit said data (11) and when said source port (33) is busy transmitting other data (11); when said source and destination ports (33) are available, transferring said data (11) from said source port (33) to said destination port (33); when either of said source and destination ports (33) is busy, denying transfer of said data (11) from said source port (33) to said destination port (33); defining an order for future access to said source port (33) as a source for data (11), said order including a designation of at least one destination port (33) corresponding to at least one denied transfer request; and after said source port (33) terminates said busy condition, permitting a denied transfer request by acquiring a destination port (33) designation based upon said order.
Claim 10
Independent Claim
215 words
A method (130) for insuring efficient and reliable transfer of data (11) through a fiber optic switch (30) for selectively interconnecting fiber optic channels (32) which are connected to the switch (30) via respective ports (33), comprising the steps of: receiving data (11) at said switch (30) from a source port (33), said data to be switched to a destination port (33); determining when said destination port (33) is available to receive said data (11) and when said destination port (33) is busy receiving other data (11); determining when said source port (33) is available to transmit said data (11) and when said source port (33) is busy transmitting other data (11); when said source and destination ports (33) are available, transferring said data (11) from said source port (33) to said destination port (33); when either of said source and destination ports (33) is busy, denying transfer of said data (11) from said source port (33) to said destination port (33); defining an order for future access to said destination port (33) as a destination for data (11), said order including a designation of at least one source port (33) corresponding to at least one denied transfer request; and permitting a denied transfer request by acquiring a source port designation based upon said order.
References Cited (Backward Citations)
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