DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments are moot in view of the new ground(s) of rejection.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-2, 5-6, 9-10, 12-16 are rejected under 35 U.S.C. 103 as being unpatentable over Vasseur et al. (US 20090182894, hereinafter, “Vasseur”) in view of Mukhopadhyay et al. (US 10778326 B1, hereinafter, “Mukhopadhyay”), and further in view of Przygienda et al. (US 20170324650, hereinafter, “Przygienda”).
Claim 1. Vasseur teaches: A method implemented by a secondary controller in a controller cluster including a primary controller and the secondary controller, comprising: - See Fig. 6, ¶ [0035], (“a first PCE…the backup PCE may be advertised into the first domain, thus appearing as a local PCE for the nodes in the first domain”, multiple PCEs behave as clustered controllers)
transmitting a first message to a network element (NE) in communication with the primary controller and the secondary controller, - in ¶ [0042], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE. For instance, the newly formed adjacency between the first PCE and backup PCE may be announced as new link in the first domain, such that the PCCs in the first domain (e.g., router A and B) may determine a path to reach the backup PCE that is "within" their domain.”, backup PCE sends a message to the first domain (eq. network element))
wherein the first message includes a controllers type length value (TLV) structure with an indication that the secondary controller is attempting to promote itself to a new primary controller for the controller cluster based on detection of the failure, - in ¶ [0037 - 0038], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE…A failure, therefore, may be detected by a lack of response from the other PCE (of the first and second PCEs). This failure, in turn, may generate a "backup event"”); ¶ [0042 - 0043], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE…Since the backup PCE has been announced into the first domain as a new PCE operating on behalf of the first domain”, this describes the backup PCE announcing/advertising its availability for use as a PCE. By advertising itself into the domain, the backup PCE is signaling its availability to take over to the first domain (eq. attempting to promote itself to a new primary controller); the purpose of the backup advertising itself is to replace the first PCE after detecting failure)
receiving a second message from the network element, wherein the second message includes a second controllers TLV structure that indicates a status of the primary controller; - in ¶ [0031], (“The fields of the TLV 400 and sub-TLV(s) 450 are used in a variety of manners in messages/advertisements 300”)
Vasseur does not explicitly teach:
detecting a failure of a communication link between the primary controller and the secondary controller;
receiving a second message from the network element, wherein the second message includes a second controllers TLV structure that indicates a status of the primary controller; and
determining to maintain its position as the secondary controller for the controller cluster when the status of the primary controller is active.
However, Mukhopadhyay teaches:
detecting a failure of a communication link between the primary controller and the secondary controller; - See Fig. 4, 7, 10, Col. 15, lines 6-9, (“in response to a failure of the active MCU, a failure of the standby MCU, or a loss of communication between the active MCU and the standby MCU.”); See Fig. 10, Col. 26, lines 24-29, (“detect a loss of communication between two MCUs and to take corrective action to provide redundancy in the control plane of the disaggregated network element following the loss of communication”)
receiving a second message from the network element, - See Fig. 7, Col. 22, lines 59-65, (“At 708, method 700 includes the first MCU requesting and receiving, from a given tributary unit designated as a witness tributary unit, an indication of the health of the second MCU. For example, the given tributary unit may be configured to perform health checks on various MCUs periodically or on demand and to return results to the first MCU.”) wherein the second message includes a second controllers TLV structure that indicates a status of the primary controller; - See Fig. 9, 10, Col. 25, lines 28-39, (“At 912, method 900 includes the given MCU requesting that a tributary unit designated as the witness tributary unit attempt to communicate with peer MCU and determine whether the peer is the active MCU…If, at 914, the witness tributary unit is able to communicate with the peer MCU, method 900 continues at 916… If, at 916, it is determined that the peer MCU is active, method 900 continues at 920, where the given MCU remains a standby MCU. Otherwise, the method proceeds to 918, where the given MCU becomes the active MCU.”, the tributary unit notifies the given MCU if the peer MCU is active. If status of peer MCU is not active [Wingdings font/0xE0] given MCU becomes the active MCU. If status of peer MCU is active [Wingdings font/0xE0] given MCU remains a standby MCU) and
determining to maintain its position as the secondary controller for the controller cluster when the status of the primary controller is active. - See Fig. 9, 10, Col. 25, lines 28-39, (“At 912, method 900 includes the given MCU requesting that a tributary unit designated as the witness tributary unit attempt to communicate with peer MCU and determine whether the peer is the active MCU…If, at 914, the witness tributary unit is able to communicate with the peer MCU, method 900 continues at 916… If, at 916, it is determined that the peer MCU is active, method 900 continues at 920, where the given MCU remains a standby MCU. Otherwise, the method proceeds to 918, where the given MCU becomes the active MCU.”, the tributary unit notifies the given MCU if the peer MCU is active. If status of peer MCU is not active [Wingdings font/0xE0] given MCU becomes the active MCU. If status of peer MCU is active [Wingdings font/0xE0] given MCU remains a standby MCU); Col. 25, lines 48-49, (“while ensuring that no two MCUs are designated as the active MCU at the same time”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur with Mukhopadhyay to incorporate specific failure handling, as taught by Mukhopadhyay. One of ordinary skill in the art would have been motivated to make this modification to avoid split-brain scenarios where two primary controllers control the network at the same time, as suggested by Mukhopadhyay, while ensuring that no two MCUs are designated as the active MCU at the same time Using this approach, in case of a failure of the currently active MCU, a standby MCU may take over as the newly active MCU to manage the network element without causing any disruption to user traffic in the data plane. - See Col. 25, lines 48-53
Combination of Vasseur and Mukhopadhyay does not explicitly teach:
wherein the controllers TLV structure further identifies a number of controllers advertising the controllers TLV structure, an old position of the secondary controller, a priority of the secondary controller, and an identifier (ID) of the secondary controller;
However, Przygienda teaches:
wherein the controllers TLV structure - See Fig. 3, ¶ [0042], (“BIER-PE packet 300 is advertised/distributed by each BFR…and contains one or more of the set info blocks illustrated in FIG. 3”) further identifies a number of controllers advertising the controllers TLV structure, - See Fig. 3, (# Of Set Elections The number of set info blocks that are repeated in this packet) an old position of the secondary controller, - See Fig. 3, ( BD-BFR ID The router ID of the BFR that has been elected as the BD-BFR) a priority of the secondary controller, (D-BFR Priority) and an identifier (ID) of the secondary controller; - See Fig. 3, (D-BFR ID The router ID of the BFR that has been elected as the D-BFR)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur and Mukhopadhyay with Przygienda to include controllers TLV structure identifiers, as taught by Przygienda. One of ordinary skill in the art would have been motivated to make this modification to ensure a specific implementation when a controller fails, as suggested by Przygienda, The reason behind the election algorithm's complexity is the desire for an orderly transition from BD-BFR<T,S> to D-BFR<T,S>, when the current D-BFR<T,S> fails. - ¶ [0048]
Claim 2. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 1, - refer to the indicated claim for reference(s).
Vasseur teaches:
wherein the indication in the controllers TLV structure that the secondary controller is attempting to promote itself comprises a C-bit set to a first value and a position field set to a second value. - See Fig. 3, 4, ¶ [0037], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE.”); ¶ [0042] Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE.”); [0031], (“The TLV 400 is organized to include a Type field 405 containing a predetermined type value indicating the type of data contained in the TLV 400, and a Length field 410, which is a variable length value.”)
Claim 5. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 1, - refer to the indicated claim for reference(s).
Vasseur teaches:
wherein one or more of the first message and the second message are exchanged over an information channel. – in ¶ [0041 - 0042], (“informing the backup PCE of the path computation information as mentioned above may include the exchange of databases 245 in the PCOL message 500…through conventional route synchronization techniques to exchange the information over the routing adjacency as just mentioned…the PCCs in the first domain (e.g., router A and B) may determine a path to reach the backup PCE that is "within" their domain.”)
Claim 6. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 1, - refer to the indicated claim for reference(s).
Vasseur teaches:
wherein one or more of the primary controller and the secondary controller is a path computational element (PCE), and wherein the network element is a path computational client (PCC). - in ¶ [0042], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE. For instance, the newly formed adjacency between the first PCE and backup PCE may be announced as new link in the first domain, such that the PCCs in the first domain (e.g., router A and B) may determine a path to reach the backup PCE…”)
Claim 9. Vasseur teaches: A method implemented by a secondary controller in a controller cluster including a primary controller and the secondary controller, comprising: - See Fig. 6, ¶ [0035], (“a first PCE…the backup PCE may be advertised into the first domain, thus appearing as a local PCE for the nodes in the first domain”, multiple PCEs behave as clustered controllers)
detecting a potential failure of the primary controller; - in ¶ [0038], (“The first and second PCEs may monitor each other using conventional routing procedures (e.g., "hello" messages), or through…Bi-directional Forwarding Detection (BFD) messages, etc. A failure, therefore, may be detected by a lack of response from the other PCE (of the first and second PCEs). This failure, in turn, may generate a "backup event", such that the surviving PCE initializes the backup PCE for load balancing”)
transmitting a first message to a network element (NE) in communication with the primary controller and the secondary controller, - in ¶ [0042], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE. For instance, the newly formed adjacency between the first PCE and backup PCE may be announced as new link in the first domain, such that the PCCs in the first domain (e.g., router A and B) may determine a path to reach the backup PCE that is "within" their domain.”, backup PCE sends a message to the first domain (eq. network element))
wherein the first message includes a controllers type length value (TLV) structure - in ¶ [0037 - 0038], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE…A failure, therefore, may be detected by a lack of response from the other PCE (of the first and second PCEs). This failure, in turn, may generate a "backup event"”) with an indication that the secondary controller is attempting to promote itself to a new primary controller for the controller cluster based on detection of the potential failure, - in ¶ [0042 - 0043], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE…Since the backup PCE has been announced into the first domain as a new PCE operating on behalf of the first domain”, this describes the backup PCE announcing/advertising its availability for use as a PCE. By advertising itself into the domain, the backup PCE is signaling its availability to take over to the first domain (eq. attempting to promote itself to a new primary controller); the purpose of the backup advertising itself is to replace the first PCE after detecting failure)
failing to receive, within a predetermined period of time, a second message from the network element indicating that the primary controller is still active; and promoting itself to the new primary controller for the controller cluster. - in ¶ [0038], (“The first and second PCEs may monitor each other using conventional routing procedures (e.g., "hello" messages)…A failure, therefore, may be detected by a lack of response from the other PCE (of the first and second PCEs). This failure, in turn, may generate a "backup event", such that the surviving PCE initializes the backup PCE for load balancing as described herein (e.g., after a configured timer to ensure that the failure/event is non-transient).”)
Vasseur does not explicitly teach:
failing to receive, within a predetermined period of time, a second message from the network element indicating that the primary controller is still active; and promoting itself to the new primary controller for the controller cluster.
However, Mukhopadhyay teaches:
failing to receive, within a predetermined period of time, a second message from the network element indicating that the primary controller is still active; - See Fig. 9, 10, Col. 25, lines 28-39, (“At 912, method 900 includes the given MCU requesting that a tributary unit designated as the witness tributary unit attempt to communicate with peer MCU and determine whether the peer is the active MCU…If, at 914, the witness tributary unit is able to communicate with the peer MCU, method 900 continues at 916… If, at 916, it is determined that the peer MCU is active, method 900 continues at 920, where the given MCU remains a standby MCU. Otherwise, the method proceeds to 918, where the given MCU becomes the active MCU.”, the tributary unit (eq. network element) notifies the given MCU if the peer MCU is active. If status of peer MCU is not active [Wingdings font/0xE0] given MCU becomes the active MCU. If status of peer MCU is active [Wingdings font/0xE0] given MCU remains a standby MCU) and
promoting itself to the new primary controller for the controller cluster. - See Fig. 9, 10, Col. 25, lines 28-39, (“If, at 916, it is determined that the peer MCU is active, method 900 continues at 920, where the given MCU remains a standby MCU. Otherwise, the method proceeds to 918, where the given MCU becomes the active MCU.”, the tributary unit (eq. network element) notifies the given MCU if the peer MCU is active. If status of peer MCU is not active [Wingdings font/0xE0] given MCU becomes the active MCU. If status of peer MCU is active [Wingdings font/0xE0] given MCU remains a standby MCU); Col. 14, lines 53-56, (“the second MCU promoting itself from a designation as a standby MCU for the management and control plane to a designation as the active MCU for the management and control plane.”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur with Mukhopadhyay to incorporate specific failure handling, as taught by Mukhopadhyay. One of ordinary skill in the art would have been motivated to make this modification to avoid split-brain scenarios where two primary controllers control the network at the same time, as suggested by Mukhopadhyay, while ensuring that no two MCUs are designated as the active MCU at the same time Using this approach, in case of a failure of the currently active MCU, a standby MCU may take over as the newly active MCU to manage the network element without causing any disruption to user traffic in the data plane. - See Col. 25, lines 48-53
Combination of Vasseur and Mukhopadhyay does not explicitly teach:
wherein the controllers TLV structure further identifies a number of controllers advertising the controllers TLV structure and an old position of the secondary controller;
However, Przygienda teaches:
wherein the controllers TLV structure - See Fig. 3, ¶ [0042], (“BIER-PE packet 300 is advertised/distributed by each BFR…and contains one or more of the set info blocks illustrated in FIG. 3”) further identifies a number of controllers advertising the controllers TLV structure - See Fig. 3, (# Of Set Elections The number of set info blocks that are repeated in this packet) and an old position of the secondary controller; - See Fig. 3, ( BD-BFR ID The router ID of the BFR that has been elected as the BD-BFR)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur and Mukhopadhyay with Przygienda to include controllers TLV structure identifiers, as taught by Przygienda. One of ordinary skill in the art would have been motivated to make this modification to ensure a specific implementation when a controller fails, as suggested by Przygienda, The reason behind the election algorithm's complexity is the desire for an orderly transition from BD-BFR<T,S> to D-BFR<T,S>, when the current D-BFR<T,S> fails. - ¶ [0048]
Claim 12. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 9, - refer to the indicated claim for reference(s).
Vasseur teaches:
further comprising removing an information channel between the secondary controller and the network element - in ¶ [0045], (“the first PCE may notify the backup PCE that the second PCE has resumed operation, at which time the backup PCE may discontinue its operation for the first domain (e.g., after having processed all the pending requests). Also, at this time, the first PCE and the backup PCE may tear down their routing adjacency and corresponding tunnels to free up network resources.”, the ‘information channel’ corresponds to the routing adjacency and tunnels which are removed/torn down) and
establishing a control channel between the secondary controller and the network element after the secondary controller has promoted itself to the new primary controller for the controller cluster. – in ¶ [0042], (“the newly formed adjacency between the first PCE and backup PCE may be announced as new link in the first domain…may determine a path to reach the backup PCE that is "within" their domain…¶ [0043] Since the backup PCE has been announced into the first domain as a new PCE operating on behalf of the first domain, the PCCs (e.g., routers A and B) may begin to send requests to the first and backup PCEs to load-balance their requests.”, the ‘control channel’ is reflected in the advertisement of the backup PCE into the domain and the ability of PCCs to send request to it (eq. operational control communication is established))
Claim 13. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 10, - refer to the indicated claim for reference(s).
Vasseur teaches:
further comprising transmitting, to the network element, a third message including an updated controllers TLV structure, - in ¶ [0048], (“routing databases of the first domain (e.g., LSDBs/TEDs 245, etc.) may be exchanged over the routing adjacency in step 740. The first PCE also advertises the backup PCE into first domain in step 745, e.g., by generating its own advertisement or, illustratively, by forwarding an advertisement generated by the backup PCE and sent over the tunnels.”); ¶ [0049], (“If the backup event in step 720 was a failed second PCE, the first and/or backup PCE may determine in step 760 that the second PCE has recovered. If so, then in step 765 the operation of the backup PCE may be discontinued (for the first domain) and operation of second PCE may resume accordingly.”, this describes PCEs dynamically changing roles and resuming or discontinuing operation)
the updated controllers TLV structure comprising the C-bit set to the first value and the position field set to the second value - See Fig. 3, 4, ¶ [0037], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE.”); ¶ [0042] Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE.”); [0031], (“The TLV 400 is organized to include a Type field 405 containing a predetermined type value indicating the type of data contained in the TLV 400, and a Length field 410, which is a variable length value.”) to indicate that the secondary controller is the new primary controller, wherein the first value is one. - in ¶ [0037 - 0038], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE…A failure, therefore, may be detected by a lack of response from the other PCE (of the first and second PCEs). This failure, in turn, may generate a "backup event"”); ¶ [0042 - 0043], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE…Since the backup PCE has been announced into the first domain as a new PCE operating on behalf of the first domain”)
Przygienda further teaches:
wherein the first value is one. – in ¶ [0034], (BM bit that is set to “1”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur and Mukhopadhyay with Przygienda to include the first value is one, as taught by Przygienda. One of ordinary skill in the art would have been motivated to make this modification to ensure a specific implementation when a controller fails, as suggested by Przygienda, The reason behind the election algorithm's complexity is the desire for an orderly transition from BD-BFR<T,S> to D-BFR<T,S>, when the current D-BFR<T,S> fails. - ¶ [0048]
Claim 14. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 13, - refer to the indicated claim for reference(s).
Vasseur teaches:
wherein the first message is transmitted over an information channel, and wherein the third message is transmitted over the information channel or a control channel. – in ¶ [0041 - 0042], (“Notably, informing the backup PCE of the path computation information as mentioned above may include the exchange of databases 245 in the PCOL message 500, or, illustratively, through conventional route synchronization techniques to exchange the information over the routing adjacency as just mentioned…the PCCs in the first domain (e.g., router A and B) may determine a path to reach the backup PCE that is "within" their domain.”)
Claim 16. Vasseur teaches: A method implemented by a network element (NE) in communication with a primary controller and a secondary controller in a controller cluster, comprising: - See Fig. 6, ¶ [0035], (“a first PCE…the backup PCE may be advertised into the first domain, thus appearing as a local PCE for the nodes in the first domain”, multiple PCEs behave as clustered controllers)
receiving a first message from the secondary controller, wherein the first message includes a controllers type length value (TLV) structure - in ¶ [0037 - 0038], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE…A failure, therefore, may be detected by a lack of response from the other PCE (of the first and second PCEs). This failure, in turn, may generate a "backup event"”) with an indication that the secondary controller is attempting to promote itself to a new primary controller for the controller cluster based on detection of a failure of a communication link between the primary controller and the secondary controller; - in ¶ [0042], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE. For instance, the newly formed adjacency between the first PCE and backup PCE may be announced as new link in the first domain, such that the PCCs in the first domain (e.g., router A and B) may determine a path to reach the backup PCE that is "within" their domain.”, backup PCE sends a message to the first domain (eq. network element))
receiving a second message from the primary controller, wherein the second message includes a second controllers type length value (TLV) structure with an indication that the primary controller is still active; - in ¶ [0031], (“The fields of the TLV 400 and sub-TLV(s) 450 are used in a variety of manners in messages/advertisements 300”) and
Vasseur does not explicitly teach:
receiving a first message from the secondary controller, wherein the first message includes a controllers type length value (TLV) structure with an indication that the secondary controller is attempting to promote itself to a new primary controller for the controller cluster based on detection of a failure of a communication link between the primary controller and the secondary controller,
transmitting the first message to the primary controller;
receiving a second message from the primary controller, wherein the second message includes a second controllers type length value (TLV) structure with an indication that the primary controller is still active; and transmitting the second message to the secondary controller to prevent the secondary controller from promoting itself to the new primary controller.
However, Mukhopadhyay teaches:
receiving a first message from the secondary controller, wherein the first message includes a controllers type length value (TLV) structure with an indication that the secondary controller is attempting to promote itself to a new primary controller for the controller cluster based on detection of a failure of a communication link between the primary controller and the secondary controller, - See Fig. 4, 7, 10, Col. 15, lines 6-9, (“in response to a failure of the active MCU, a failure of the standby MCU, or a loss of communication between the active MCU and the standby MCU.”); See Fig. 10, Col. 26, lines 24-29, (“method 1000 may repeat continuously or periodically to detect a loss of communication between two MCUs and to take corrective action to provide redundancy in the control plane of the disaggregated network element following the loss of communication”)
transmitting the first message to the primary controller; - See Col. 16. Lines 46-55, (“to determine the health of a peer MCU, a management and control message may be sent by the witness tributary unit to the peer MCU to initiate an internal health check on the peer MCU…The results of the internal health check may be returned to the witness tributary unit as an indication of the health of the peer MCU and may include an indication of whether the peer MCU is currently designated as the active MCU or is currently designated as a standby MCU.”)
receiving a second message from the primary controller, wherein the second message includes a second controllers type length value (TLV) structure with an indication that the primary controller is still active; - See Col. 16. Lines 46-55, (“to determine the health of a peer MCU, a management and control message may be sent by the witness tributary unit to the peer MCU to initiate an internal health check on the peer MCU…The results of the internal health check may be returned to the witness tributary unit as an indication of the health of the peer MCU and may include an indication of whether the peer MCU is currently designated as the active MCU or is currently designated as a standby MCU.”) and
transmitting the second message to the secondary controller to prevent the secondary controller from promoting itself to the new primary controller. – See [Col. 16, lines 65- Col. 17, line 1], (“the witness tributary unit may return a management and control message to the given MCU that requested the health check indicating that the peer MCU has not failed.”); See Fig. 9-10, Col. 25, lines 28-39, (“At 912, method 900 includes the given MCU requesting that a tributary unit designated as the witness tributary unit attempt to communicate with peer MCU and determine whether the peer is the active MCU…If, at 914, the witness tributary unit is able to communicate with the peer MCU, method 900 continues at 916… If, at 916, it is determined that the peer MCU is active, method 900 continues at 920, where the given MCU remains a standby MCU. Otherwise, the method proceeds to 918, where the given MCU becomes the active MCU.”, the tributary unit notifies the given MCU if the peer MCU is active. If status of peer MCU is not active [Wingdings font/0xE0] given MCU becomes the active MCU. If status of peer MCU is active [Wingdings font/0xE0] given MCU remains a standby MCU); Col. 25, lines 48-49, (“while ensuring that no two MCUs are designated as the active MCU at the same time”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur with Mukhopadhyay to incorporate specific failure handling, as taught by Mukhopadhyay. One of ordinary skill in the art would have been motivated to make this modification to avoid split-brain scenarios where two primary controllers control the network at the same time, as suggested by Mukhopadhyay, while ensuring that no two MCUs are designated as the active MCU at the same time Using this approach, in case of a failure of the currently active MCU, a standby MCU may take over as the newly active MCU to manage the network element without causing any disruption to user traffic in the data plane. - See Col. 25, lines 48-53
Combination of Vasseur and Mukhopadhyay does not explicitly teach:
wherein the controllers TLV structure further identifies a number of controllers advertising the controllers TLV structure and an old position of the secondary controller;
However, Przygienda teaches:
wherein the controllers TLV structure - See Fig. 3, ¶ [0042], (“BIER-PE packet 300 is advertised/distributed by each BFR…and contains one or more of the set info blocks illustrated in FIG. 3”) further identifies a number of controllers advertising the controllers TLV structure - See Fig. 3, (# Of Set Elections The number of set info blocks that are repeated in this packet) and an old position of the secondary controller; - See Fig. 3, ( BD-BFR ID The router ID of the BFR that has been elected as the BD-BFR)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur and Mukhopadhyay with Przygienda to include controllers TLV structure identifiers, as taught by Przygienda. One of ordinary skill in the art would have been motivated to make this modification to ensure a specific implementation when a controller fails, as suggested by Przygienda, The reason behind the election algorithm's complexity is the desire for an orderly transition from BD-BFR<T,S> to D-BFR<T,S>, when the current D-BFR<T,S> fails. - ¶ [0048]
Claim 10 is rejected under the same rationale as Claim 2 since they recite nearly identical limitations.
Claim 15 is rejected under the same rationale as Claim 6 since they recite nearly identical limitations.
Claims 3, 7-8, 11, 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Vasseur et al. (US 20090182894, hereinafter, “Vasseur”) in view of Mukhopadhyay et al. (US 10778326 B1, hereinafter, “Mukhopadhyay”), and further in view of Przygienda et al. (US 20170324650, hereinafter, “Przygienda”) and Chen (US 20170257228, hereinafter, “Chen”, provided in the IDS by the applicant).
Claim 3. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 2, - refer to the indicated claim for reference(s).
Combination of Vasseur, Mukhopadhyay, and Przygienda does not explicitly teach:
wherein the first value is zero and the second value is one.
However, Chen teaches:
wherein the first value is zero and the second value is one. - in ¶ [0096 - 0100], (describes bits being set to 0 or 1 to indicate specific capabilities); ¶ [0120 - 0134]
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur, Mukhopadhyay, and Przygienda with Chen to include the first value is zero and the second value is one, as taught by Chen. One of ordinary skill in the art would have been motivated to make this modification to optimize the decision-making process during a communication failure and ensure a specific implementation for the indication, as suggested by Chen, the first request message and the second request message each comprise a Controller Request Parameters (CRP) type-length-value (TLV). Optionally, in any of the preceding embodiments, the CRP TLV specifies an optimization scheme. - ¶ [0008]
Claim 7. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 1, - refer to the indicated claim for reference(s).
Chen further teaches:
further comprising transmitting an open message to the network element to indicate a capability for high availability of controllers (HAC). - in ¶ [0106 - 0107], (“The first CSC capability triplet 300 is included…in an Open Message transmitted by the distributed controller 210A to the distributed controller 210B.”, this shows an open message is being sent to another network element; CSC capability triplet indicates controller capability; HAC implies redundancy and fault tolerance which is supported by distributed relation between controllers)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur, Mukhopadhyay, and Przygienda with Chen to include transmitting an open message to the network element to indicate a capability for HAC, as taught by Chen. One of ordinary skill in the art would have been motivated to make this modification to enable advanced network management, as suggested by Chen, The concepts of Software Defined Networks (SDN) reduce the overall network Capital Expenditure (CapEx). The principles of SDN include centralized control to allow optimized usage of network resources and provisioning of network elements across domains. - ¶ [0004]
Claim 8. Combination of Vasseur, Mukhopadhyay, Przygienda, and Chen teaches The method of claim 7, - refer to the indicated claim for reference(s).
Chen further teaches:
wherein the open message includes an open object, wherein the open object includes a controller capability TLV structure, - in ¶ [0106], (“The first CSC capability triplet 300 is included, for example in an Open Message”, this shows that the CSC capability triplet (open object) serves as the controller capability TLV structure) wherein the controller capability TLV structure includes a second C-bit, wherein the second C-bit is set to a first value to indicate the secondary controller is a controller. - in ¶ [0106], (“The first CSC capability triplet 300 contains a Distributed Controller bit set to “1,”…The first CSC capability triplet 300 indicates to the distributed controller 210B that the distributed controller 210A is a distributed controller”, the Distributed Controller bit (C-bit) is set to 1 to confirm the controller’s identity)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur, Mukhopadhyay, and Przygienda with Chen to include the open message includes an open object, as taught by Chen. One of ordinary skill in the art would have been motivated to make this modification to optimize the decision-making process during a communication failure and ensure a specific implementation, as suggested by Chen, the first request message and the second request message each comprise a Controller Request Parameters (CRP) type-length-value (TLV). Optionally, in any of the preceding embodiments, the CRP TLV specifies an optimization scheme. - ¶ [0008]
Claim 17. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 16, - refer to the indicated claim for reference(s).
Vasseur teaches:
wherein the indication in the controllers TLV structure that the secondary controller is attempting to promote itself comprises a C-bit set to a first value and a position field set to a second value, wherein the first value is zero and the second value is one. - See Fig. 3, 4, ¶ [0037], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE.”); ¶ [0042] Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE.”); [0031], (“The TLV 400 is organized to include a Type field 405 containing a predetermined type value indicating the type of data contained in the TLV 400, and a Length field 410, which is a variable length value.”)
Chen further teaches:
wherein the first value is zero and the second value is one. - in ¶ [0096 - 0100], (describes bits being set to 0 or 1 to indicate specific capabilities); ¶ [0120 - 0134]
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur, Mukhopadhyay, and Przygienda with Chen to include the first value is zero and the second value is one, as taught by Chen. One of ordinary skill in the art would have been motivated to make this modification to optimize the decision-making process during a communication failure and ensure a specific implementation for the indication, as suggested by Chen, the first request message and the second request message each comprise a Controller Request Parameters (CRP) type-length-value (TLV). Optionally, in any of the preceding embodiments, the CRP TLV specifies an optimization scheme. - ¶ [0008]
Claim 18. Combination of Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 16, - refer to the indicated claim for reference(s).
Vasseur teaches:
wherein the indication in the second controllers TLV structure that the primary controller is still active comprises a second C-bit set to one and a second position field set to one. - in ¶ [0031], (“The fields of the TLV 400 and sub-TLV(s) 450 are used in a variety of manners in messages/advertisements 300”)
Mukhopadhyay teaches:
wherein the indication in the second controllers TLV structure that the primary controller is still active comprises a second C-bit set to one and a second position field set to one. - See Fig. 9, 10, Col. 25, lines 28-39, (“…determine whether the peer is the active MCU…If, at 914, the witness tributary unit is able to communicate with the peer MCU… If, at 916, it is determined that the peer MCU is active, method 900 continues at 920, where the given MCU remains a standby MCU. Otherwise, the method proceeds to 918, where the given MCU becomes the active MCU.”, the tributary unit notifies the given MCU if the peer MCU is active.”)
Chen teaches:
wherein the indication in the second controllers TLV structure that the primary controller is still active comprises a second C-bit set to one and a second position field set to one. - See Fig. 11, ¶ [0096 - 0100], (describes bits being set to 0 or 1 to indicate specific capabilities); ¶ [0120], (“The ISIS Router-ID Sub-TLV 1100 includes, in some embodiments, a Type field 1110, a Length field 1120, and an International Organization for Standardization (ISO) Node-ID field 1130…The ISO Node-ID field 1030 includes an identification of a node conforming to ISO standards which is capable of performing ISIS routing and which is associated with an end point of a connection associated with the CAA NLRI TLV 700.”, The ISO Node-ID field identifies a node associated with a connection (position); ¶ [0120 - 0134], (Any field with a value can map to C-bit set and position field (e.g. ISO Node-ID field maps to C-bit set))
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Vasseur, Mukhopadhyay, and Przygienda with Chen to incorporate the indication in the controllers TLV structure comprises a second C-bit set to one and a second position field set to one, as taught by Chen. One of ordinary skill in the art would have been motivated to make this modification to optimize the decision-making process during a communication failure, as suggested by Chen, the first request message and the second request message each comprise a Controller Request Parameters (CRP) type-length-value (TLV). Optionally, in any of the preceding embodiments, the CRP TLV specifies an optimization scheme. - ¶ [0008]
Claim 11 is rejected under the same rationale as Claim 3 since they recite nearly identical limitations.
Claims 19, 21 are rejected under 35 U.S.C. 103 as being unpatentable over SHIM et al. (US 20100205273, hereinafter, “SHIM”) in view of Vasseur et al. (US 20090182894, hereinafter, “Vasseur”), and further in view of Mukhopadhyay et al. (US 10778326 B1, hereinafter, “Mukhopadhyay”) and Przygienda et al. (US 20170324650, hereinafter, “Przygienda”).
Claim 19. SHIM teaches: A method implemented by a secondary controller in a controller cluster, comprising: - See Fig. 4-5
detecting a failure that divides the controller cluster into a first controller group and a second controller group, wherein the second controller group includes the secondary controller; - See Fig. 4-6, ¶ [0056], (“a network split-brain problem occurs, for example, in a cluster consisting of seven nodes in total and the cluster is split into group A including four nodes and group B including three nodes”)
transmitting a first message to a network element (NE) in communication with each controller in the controller cluster, wherein the first message includes a controllers type length value (TLV) structure identifying the secondary controller as an intended primary controller for the second controller group, - in ¶ [0014], (“determining the first group or the second group as the major group using at least one of a result of comparing the number of nodes and the history information.”); ¶ [0057], (“since group A secures more than half of the total nodes (i.e., seven nodes), the quorum is satisfied, and thus, group A can be classified as a major group. Accordingly, one of the nodes included in the major group is determined as a master node, and communication with the client 300 can be performed through the master node.”, the secondary controller in the split group corresponds to a node in its group. When it is chosen as the “master”, it is the intended primary controller for the second group)
a total number of controllers in the second controller group, - See Fig. 6, ¶ [0081], (“When a network split-brain problem occurs…the distributed environment management system 200 confirms and compares the number of total nodes included in the existing group and the number of nodes included in each of the split groups (610). In addition, the distributed environment management system 200 confirms history information of the nodes of each split group using the history table described above (620)”) and
a prior position of the secondary controller in the controller cluster; - See Fig. 6, ¶ [0081], (“the distributed environment management system 200 confirms history information of the nodes of each split group using the history table described above (620)”); - See Fig. 6, ¶ [0073], (“The node state information, which is the third field of the history table, is changed into master or slave whenever a new master node is elected, and the group state information is changed to major or minor as a network split-brain problem occurs.”, the history table stores prior positions (master or slave) of the nodes (eq. prior position of the secondary controller))
receiving a second message from the NE, wherein the second message includes a second controllers TLV structure identifying a primary controller from the first controller group as an intended primary controller for the first controller group, - in ¶ [0057], (“since group A secures more than half of the total nodes (i.e., seven nodes), the quorum is satisfied, and thus, group A can be classified as a major group. Accordingly, one of the nodes included in the major group is determined as a master node, and communication with the client 300 can be performed through the master node.”, a master node (eq. primary controller) of the other group is determined based on quorum)
a number of controllers in the first controller group, - See Fig. 6, ¶ [0081], (“When a network split-brain problem occurs (600) and a group is then split into two or more groups, the distributed environment management system 200 confirms and compares the number of total nodes included in the existing group and the number of nodes included in each of the split groups (610). In addition, the distributed environment management system 200 confirms history information of the nodes of each split group using the history table described above (620)”) and
a prior position of the primary controller in the controller cluster, - See Fig. 6, ¶ [0073], (“The history table shown above can be created when a group is initially configured and can be maintained until the function of the group is ended. The node state information, which is the third field of the history table, is changed into master or slave whenever a new master node is elected, and the group state information is changed to major or minor as a network split-brain problem occurs.”, the history table stores prior positions (master or slave) of the nodes (eq. prior position of the primary controller))
comparing the number of controllers in the first controller group to the number of controllers in the second controller group; - See Fig. 6, ¶ [0081], (“When a network split-brain problem occurs (600) and a group is then split into two or more groups, the distributed environment management system 200 confirms and compares the number of total nodes included in the existing group and the number of nodes included in each of the split groups (610). In addition, the distributed environment management system 200 confirms history information of the nodes of each split group using the history table described above (620)”)
determining to maintain its position as the secondary controller for the controller cluster when the number of controllers in the first controller group exceeds the number of controllers in the second controller group; - in ¶ [0077 – 0078], (“Thereafter, a network split-brain problem occurs again, and the group is split into a group including node #1 and a group including node #3 and node #5. Since the group including node #3 and node #5 satisfies the quorum, it is determined as a major group, and the group including node #1 is changed to a minor group.”); ¶ [0058], (“On the other hand, since group B secures less than half of the nodes, it is classified as a minor group. A master node will not be elected from such a minor group.”) and
promoting itself to a new primary controller for the controller cluster when the number of controllers in the second controller group exceeds the number of controllers in the first controller group. - in ¶ [0057], (“since group A secures more than half of the total nodes (i.e., seven nodes), the quorum is satisfied, and thus, group A can be classified as a major group. Accordingly, one of the nodes included in the major group is determined as a master node, and communication with the client 300 can be performed through the master node.”)
SHIM does not explicitly teach:
transmitting a first message to a network element (NE) in communication with each controller in the controller cluster, wherein the first message includes a controllers type length value (TLV) structure identifying the secondary controller as an intended primary controller for the second controller group,
receiving a second message from the NE, wherein the second message includes a second controllers TLV structure identifying a primary controller from the first controller group as an intended primary controller for the first controller group,
promoting itself to a new primary controller for the controller cluster when the number of controllers in the second controller group exceeds the number of controllers in the first controller group.
However, Vasseur teaches:
transmitting a first message to a network element (NE) in communication with each controller in the controller cluster, wherein the first message includes a controllers type length value (TLV) structure identifying the secondary controller as an intended primary controller for the second controller group, receiving a second message from the NE, - in ¶ [0037 - 0038], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE…A failure, therefore, may be detected by a lack of response from the other PCE (of the first and second PCEs). This failure, in turn, may generate a "backup event"”); ¶ [0042 - 0043], (“Upon initializing the backup PCE with the path computation information of the first PCE, the backup PCE may be advertised/announced into the first domain for use as a PCE…Since the backup PCE has been announced into the first domain as a new PCE operating on behalf of the first domain”, this describes the backup PCE announcing/advertising its availability for use as a PCE. By advertising itself into the domain, the backup PCE is signaling its availability to take over to the first domain (eq. attempting to promote itself to a new primary controller); the purpose of the backup advertising itself is to replace the first PCE after detecting failure)
receiving a second message from the NE, wherein the second message includes a second controllers TLV structure identifying a primary controller from the first controller group as an intended primary controller for the first controller group, - in ¶ [0031], (“The fields of the TLV 400 and sub-TLV(s) 450 are used in a variety of manners in messages/advertisements 300”)
promoting itself to a new primary controller for the controller cluster when the number of controllers in the second controller group exceeds the number of controllers in the first controller group. – in ¶ [0042 - 0043], (“the backup PCE may be advertised/announced into the first domain for use as a PCE…Since the backup PCE has been announced into the first domain as a new PCE operating on behalf of the first domain”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified SHIM with Vasseur to include tlv structure and promoting itself to a new primary controller, as taught by Vasseur. One of ordinary skill in the art would have been motivated to make this modification to improve failure resolution, as suggested by Vasseur, one concern with using PCEs is that the PCE becomes a critical component, and its failure and performance have a direct impact on the rerouting times of tunnels that use the PCE for their path computation. For example, where traffic may be quickly redirected from a failed PCE to an operating PCE. - ¶ [0033]
Combination of SHIM and Vasseur does not explicitly teach:
receiving a second message from the NE, wherein the second message includes a second controllers TLV structure identifying a primary controller from the first controller group as an intended primary controller for the first controller group,
determining to maintain its position as the secondary controller for the controller cluster when the number of controllers in the first controller group exceeds the number of controllers in the second controller group;
However, Mukhopadhyay teaches:
receiving a second message from the NE, wherein the second message includes a second controllers TLV structure identifying a primary controller from the first controller group as an intended primary controller for the first controller group, - See Fig. 7, Col. 22, lines 59-65, (“At 708, method 700 includes the first MCU requesting and receiving, from a given tributary unit designated as a witness tributary unit, an indication of the health of the second MCU. For example, the given tributary unit may be configured to perform health checks on various MCUs periodically or on demand and to return results to the first MCU.”)
determining to maintain its position as the secondary controller for the controller cluster when the number of controllers in the first controller group exceeds the number of controllers in the second controller group; - See Fig. 9, 10, Col. 25, lines 28-39, (“At 912, method 900 includes the given MCU requesting that a tributary unit designated as the witness tributary unit attempt to communicate with peer MCU and determine whether the peer is the active MCU…If, at 914, the witness tributary unit is able to communicate with the peer MCU, method 900 continues at 916… If, at 916, it is determined that the peer MCU is active, method 900 continues at 920, where the given MCU remains a standby MCU. Otherwise, the method proceeds to 918, where the given MCU becomes the active MCU.”, the MCU determines to remain a standby MCU based on whether if the peer MCU is active.); Col. 25, lines 48-49, (“while ensuring that no two MCUs are designated as the active MCU at the same time”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified SHIM and Vasseur with Mukhopadhyay to include receive a second message from a network element and determining to maintain a position as the secondary controller, as taught by Mukhopadhyay. One of ordinary skill in the art would have been motivated to make this modification to avoid split-brain scenarios where two primary controllers control the network at the same time, as suggested by Mukhopadhyay, while ensuring that no two MCUs are designated as the active MCU at the same time Using this approach, in case of a failure of the currently active MCU, a standby MCU may take over as the newly active MCU to manage the network element without causing any disruption to user traffic in the data plane. - See Col. 25, lines 48-53
Combination of SHIM, Vasseur, and Mukhopadhyay does not explicitly teach:
wherein the controllers TLV structure further identifies a number of controllers advertising the controllers TLV structure and an old position of the secondary controller;
However, Przygienda teaches:
wherein the controllers TLV structure - See Fig. 3, ¶ [0042], (“BIER-PE packet 300 is advertised/distributed by each BFR…and contains one or more of the set info blocks illustrated in FIG. 3”) further identifies a number of controllers advertising the controllers TLV structure - See Fig. 3, (# Of Set Elections The number of set info blocks that are repeated in this packet) and an old position of the secondary controller; - See Fig. 3, ( BD-BFR ID The router ID of the BFR that has been elected as the BD-BFR)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified SHIM, Vasseur, and Mukhopadhyay with Przygienda to include controllers TLV structure identifiers, as taught by Przygienda. One of ordinary skill in the art would have been motivated to make this modification to ensure a specific implementation when a controller fails, as suggested by Przygienda, The reason behind the election algorithm's complexity is the desire for an orderly transition from BD-BFR<T,S> to D-BFR<T,S>, when the current D-BFR<T,S> fails. - ¶ [0048]
Claim 21. Combination of SHIM, Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 19, - refer to the indicated claim for reference(s).
SHIM teaches:
further comprising: comparing the prior position of the primary controller in the controller cluster with the prior position of the secondary controller in the controller cluster when the number of controllers in the second controller group is equal to the number of controllers in the first controller group; - in ¶ [0074], (“When a group is split into two groups having the same number of nodes due to a network split-brain problem, the distributed environment management system 200…may determine a major group using the history table…when a major group is determined among two groups having exactly the same number of nodes. More specifically, a group including a node that belonged to a major group before a network split-brain problem occurred and has the earliest time point of joining the group can be determined as a new major group…a node having the earliest time point of joining the group can also be determined as a master node of a corresponding group”, when two groups are equally sized, the system uses the recorded history of nodes to select which group will be treated as dominant and which node within that group will assume leadership (eq. comparing prior positions)) and
promoting itself to a new primary controller for the controller cluster when the prior position of the secondary controller in the controller cluster is lower than the prior position of the primary controller in the controller cluster. - in ¶ [0074], (“when a major group is determined among two groups having exactly the same number of nodes. a group including a node that belonged to a major group before a network split-brain problem occurred and has the earliest time point of joining the group can be determined as a new major group…a node having the earliest time point of joining the group can also be determined as a master node of a corresponding group”, the system looks at which node joined earlier and assigns it leadership based on prior order)
Vasseur further teaches:
promoting itself to a new primary controller for the controller cluster when the prior position of the secondary controller in the controller cluster is lower than the prior position of the primary controller in the controller cluster. – in ¶ [0042 - 0043], (“the backup PCE may be advertised/announced into the first domain for use as a PCE…Since the backup PCE has been announced into the first domain as a new PCE operating on behalf of the first domain”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified SHIM with Vasseur to include promoting itself to a new primary controller, as taught by Vasseur. One of ordinary skill in the art would have been motivated to make this modification to improve failure resolution, as suggested by Vasseur, one concern with using PCEs is that the PCE becomes a critical component, and its failure and performance have a direct impact on the rerouting times of tunnels that use the PCE for their path computation. For example, where traffic may be quickly redirected from a failed PCE to an operating PCE. - ¶ [0033]
Claims 20, 22 are rejected under 35 U.S.C. 103 as being unpatentable over SHIM et al. (US 20100205273, hereinafter, “SHIM”) in view of Vasseur et al. (US 20090182894, hereinafter, “Vasseur”), and further in view of Mukhopadhyay et al. (US 10778326 B1, hereinafter, “Mukhopadhyay”), Przygienda et al. (US 20170324650, hereinafter, “Przygienda”) and Chen (US 20170257228, hereinafter, “Chen”, provided in the IDS by the applicant).
Claim 20. Combination of SHIM, Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 19, - refer to the indicated claim for reference(s).
SHIM does not explicitly teach:
wherein the controllers TLV structure in the first message and the second controllers TLV structure in the second message each comprise a C-bit set to a first value, and wherein the first value is zero.
However, Vasseur teaches:
wherein the controllers TLV structure in the first message - See Fig. 3, 4, ¶ [0037], (“The purpose of this new TLV 400 (sub-TLV 450) is to allow the backup PCE to announce/advertise itself as a backup PCE.”) and the second controllers TLV structure in the second message each comprise a C-bit set to a first value, and wherein the first value is zero. - in ¶ [0031], (“The fields of the TLV 400 and sub-TLV(s) 450 are used in a variety of manners in messages/advertisements 300”)
Combination of SHIM, Vasseur, Mukhopadhyay, and Przygienda does not explicitly teach:
wherein the controllers TLV structure in the first message and the second controllers TLV structure in the second message each comprise a C-bit set to a first value, and wherein the first value is zero.
However, Chen teaches:
wherein the controllers TLV structure in the first message and the second controllers TLV structure in the second message each comprise a C-bit set to a first value, and wherein the first value is zero. - in ¶ [0096 - 0100], (describes bits being set to 0 or 1 to indicate specific capabilities); ¶ [0120 - 0134]
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified SHIM, Vasseur, Mukhopadhyay, and Przygienda with Chen to include the first value is zero and the second value is one, as taught by Chen. One of ordinary skill in the art would have been motivated to make this modification to optimize the decision-making process during a communication failure and ensure a specific implementation for the indication, as suggested by Chen, the first request message and the second request message each comprise a Controller Request Parameters (CRP) type-length-value (TLV)…the CRP TLV specifies an optimization scheme. - ¶ [0008]
Claim 22. Combination of SHIM, Vasseur, Mukhopadhyay, and Przygienda teaches The method of claim 19, - refer to the indicated claim for reference(s).
SHIM teaches:
further comprising receiving a third message from the NE when the secondary controller has determined to maintain its position as the secondary controller, wherein the third message includes a third controllers TLV structure identifying a primary controller from the first controller group as the new primary controller. - in ¶ [0057], (“since group A secures more than half of the total nodes (i.e., seven nodes), the quorum is satisfied, and thus, group A can be classified as a major group. Accordingly, one of the nodes included in the major group is determined as a master node, and communication with the client 300 can be performed through the master node.”, a master node (eq. primary controller) of the other group is determined based on quorum)
Chen teaches:
further comprising receiving a third message from the NE when the secondary controller has determined to maintain its position as the secondary controller, wherein the third message includes a third controllers TLV structure identifying a primary controller from the first controller group as the new primary controller. – See Fig. 1, ¶ [0113 - 0119], (“The CAA NLRI TLV 700 is implemented in a message transmitted between two network elements (e.g., between the parent controller 106 and any one or more of the child controllers 108, each of FIG. 1, and/or between any two distributed controllers 210A-210E of FIG. 2) to advertise connections of a domain associated with the network element transmitting the CAA NLRI TLV 700 with adjacent domains…the CAA NLRI TLV 700 is referred to generally as an advertisement message.”, the CRP TLV carries specific information for network operation requests); ¶ [0101], (“The parent controller 106 receives the second CSC capability triplet 300 from the child controller 108 and, based on the second CSC capability triplet, determines that the child controller 108 identified by the second CSC capability triplet 300 as a child controller is consistent with an identification of a child controller locally configured on the parent controller”)
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified SHIM, Vasseur, Mukhopadhyay, and Przygienda with Chen to incorporate messages including a controller(s) TLV structure, as taught by Chen. One of ordinary skill in the art would have been motivated to make this modification to optimize the decision-making process during a communication failure, as suggested by Chen, the first request message and the second request message each comprise a Controller Request Parameters (CRP) type-length-value (TLV). Optionally, in any of the preceding embodiments, the CRP TLV specifies an optimization scheme. - ¶ [0008]
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Shima Wasel whose telephone number is (703)756-4725. The examiner can normally be reached Monday - Friday 8:00 am - 5:00 pm.
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/SHIMA WASEL/Patent Examiner, Art Unit 2475
/KHALED M KASSIM/supervisory patent examiner, Art Unit 2475