DETAILED ACTION
This Office Action is in response to the amendment to Application Ser. No. 18/643,112 filed on July 22, 2026. Claims 1, 5, 8, 12, 15 and 18 are currently amended. Claims 1-20 are pending and are examined.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on July 22, 2026, has been entered.
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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Response to Arguments
The arguments with respect to the rejection of Claims 1-20 under 35 U.S.C. 103 have been fully considered by the Examiner.
Specifically, on pages 8-9 of the response filed July 22, 2026, Applicant argues, “The Chari-Mittal-Patrick combination does not disclose, teach, or suggest ‘intercepting, by a first router, a DHCP renewal request communicated by a local device as a unicast packet to a remote DHCP server’ and ‘in response to determining, by the first router, that the gateway address is not present in in the DHCP renewal request and the DHCP option is present in the DHCP renewal request adding, by the first router, an internet protocol (IP) address of the first router and a DHCP option to the DHCP renewal request’ as recited in amended independent Claim 1.”
For the reasons set forth in the rejection under 35 U.S.C. 112(a) set forth below, the Examiner finds that the limitation, “in response to determining, by the first router, that the gateway address is not present in in the DHCP renewal request and the DHCP option is present in the DHCP renewal request adding, by the first router, an internet protocol (IP) address of the first router and a DHCP option to the DHCP renewal request,” argued by Applicant as providing non-obviousness over the prior art of record does not have sufficient written description support in the as-filed specification.
Never-the-less, in the interest of compact prosecution, new grounds of rejection under 35 U.S.C. 103, necessitated by the amendment, are set forth in this Office Action.
Claim Interpretation
“The broadest reasonable interpretation of a method (or process) claim having contingent limitations requires only those steps that must be performed and does not include steps that are not required to be performed because the condition(s) precedent are not met.” See MPEP 2111.04 II.
Regarding method Claim 1, the following limitations recite steps that are performed only upon certain conditions being met:
“determining, by the first router, if a gateway address and a DHCP option are present in the DHCP renewal request;
in response to determining, by the first router, that the gateway address is not present in the DHCP renewal request and the DHCP option is present in the DHCP renewal request, adding, by the first router, an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device”.
Given its broadest reasonable interpretation, Claim 1 does not require the action “adding, by the first router, an internet protocol (IP address of the first router and a DHCP option to the DHCP renewal request” to be performed as it is subject to a condition, i.e., a determination that a gateway address is not present and that a DHCP option is present in the DHCP renewal request, that is not required by the claim to occur.
8. While the broadest reasonable interpretation of Claim 1 does not require the performance of steps which are contingent upon conditions that are not required to be met, for the purposes of compact prosecution, insofar as the recited limitations are definite, prior art has been applied to each limitation in this Office Action as if each step is required to be performed.
Claim Rejections - 35 USC § 112(a)
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 1-20 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 recites the limitation, “in response to determining, by the first router, that the gateway address is not present in the DHCP renewal request and the DHCP option is present in the DHCP renewal request, adding, by the first router, an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device” in lines 9-13.
Paragraph [0008] of the specification states, in part:
“The gateway address and a DHCP option are then added to the DHCP renewal request when it is determined that the gateway address and DHCP options are not present in the DHCP renewal request (emphasis added).”
Similar disclosure is recited in paragraphs [0009] and [0010] of the specification. While the specification suggests that the gateway address and a DCHP option are added to the DHCP renewal request by the first router in response to determining the gateway address and DHCP options are not present in the DHCP renewal request, there is insufficient written description support for adding the gateway address and the DHCP option to the DHCP renewal request “in response to determining, by the first router, that the gateway address is not present in the DHCP renewal request and the DHCP option is present in the DHCP renewal request” as claimed.
Dependent Claims 2-7 are rejected for the reasons presented above with respect to rejected Claim 1 in view of their dependence thereon.
Insofar as it recites similar claim elements, Claim 8 is rejected for substantially the same reasons presented above with respect to Claim 1.
Dependent Claims 9-14 are rejected for the reasons presented above with respect to rejected Claim 8 in view of their dependence thereon.
Insofar as it recites similar claim elements, Claim 15 is rejected for substantially the same reasons presented above with respect to Claim 1.
Dependent Claims 16-20 are rejected for the reasons presented above with respect to rejected Claim 15 in view of their dependence thereon.
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, 4, 5, 8, 9, 11, 12, 15, 16 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Chari et al., Pub. No. US 2005/0074015 A1, hereby “Chari”, in view of Mittal et al., Pub. No. US 2019/0007368 A1, hereby “Hooda”, in further view of the user guide by Juniper Networks, titled “Juno® OS Broadband Subscriber Sessions User Guide”, hereby “Juniper”.
Regarding Claim 1, Chari discloses “A method for performing dynamic host configuration protocol (DHCP) renewal (Chari fig. 10 and paragraphs 185 and 187: a process for preserving DCHP address assignment) comprising:
intercepting, by a first router, a DHCP renewal request communicated by a local device as a unicast packet to a remote DHCP server (Chari fig. 10 and paragraphs 40 and 186-187: DHCP relay agent on Node N, e.g., access node 1021, intercepts a DHCP Renew packet issued by a client device – while not explicitly stated, sending of the DHCP Renew packet as a unicast packet is inferred, see RFC 2131), wherein the first router is one of a plurality of routers positioned between the local device and the remote DHCP server and wherein the plurality of routers form a mesh network (Chari fig. 10 and paragraphs 28-32, 40, 44 and 186: access node 1021 and foreign gateway 1032 are part of a wireless mesh network and reside in the network path between the client device and home DHCP server 1010);” and
“... adding, by the first router, an internet protocol IP address of the first router... to the DHCP renewal request... (Chari fig. 10 and paragraph 187: access node 1021 sets the GIADDR field, i.e., the gateway address, in the DCHP Renew packet to its IP address);
forwarding, by the first router, the DHCP renewal request from the first router to the remote DHCP server (Chari fig. 10 and paragraphs 187: access node 1021 forwards the DHCP Renew packet towards home DHCP server 1010 via foreign gateway 1032);
receiving, by the first router, an acknowledgment communicated by the remote DHCP server, wherein the acknowledgment comprises the IP address of the first router (Chari fig. 10 and paragraph 188: the home gateway sets the GIADDR field of the DHCP Ack packet issued by home DHCP server 1010 to the IP address of access node 1021 and unicasts the DCHP Ack packet to access node 1021); and
forwarding, by the first router, the acknowledgment to the local device (Chari fig. 10 and paragraph 188: access node 1021, receives the DHCP ACK packet and relays it to the client device).”
However, while Chari discloses that the access node sets the GIADDR field in the DHCP renew request (Chari fig. 10 and paragraph 187), Chari does not explicitly disclose “adding, by the first router, an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device (emphasis added)”.
In the same field of endeavor, Hooda discloses adding, by a DHCP relay agent of a first network device, the IP address of the first network device and a virtual network identifier (VNI) into option 82 of a DHCP request received from a client device (Hooda figs. 1 and 2 and paragraphs 20 and 22-24: the relay agent on first network device 114 adds the address of the first network device and the VNI of first local subnet 106a to the DHCP Option 82 field of a DHCP request received from first client device 120).”
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the method of Chari to add the VNI of a first local subnet to a the relay agent information option field of the DHCP Renew packet as taught by Hooda. One of ordinary skill in the art would have been motivated to combine adding the VNI of a first local subnet to a the relay agent information option field of the DHCP Renew packet to ensure the response from the DHCP server is routed back to the first network device (Hooda paragraph 20).
However, while Hooda discloses adding, by a DHCP relay agent of a first network device, the IP address of the first network device and a virtual network identifier (VNI) into option 82 of a DHCP request received from a client device (Hooda paragraphs 20 and 22-24), the combination of Chari and Hooda does not explicitly disclose “determining, by the first router, if a gateway address and a DHCP option are present in the DHCP renewal request;
in response to determining, by the first router, that the gateway address is not present in the DHCP renewal request and the DHCP option is present in the DHCP renewal request, adding, by the first router, an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device (emphasis added)”.
In the same field of endeavor, Juniper discloses configuring the DHCP relay agent to process DHCP client packets, e.g. replacing option 82 values in the DHCP packet, when the gateway address is not present and option 82 information is set (Juniper § “Overriding Option 82 Information” and “Enable Processing of Untrusted Packets so Option 82 Information Can Be Used”: “You can override this behavior and specify that the DHCP relay agent process DHCP client packets that have a giaddr of 0 (zero) and contain option 82 information.” – while not explicitly stated, a determination by the DHCP relay agent that the gateway address (giaddr) is not present and the option 82 information is present is inferred).
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the method of Chari, as modified by Hooda, to configure the relay agent to add its IP address and VNI to option 82 of the DHCP Renew packet when a gateway address is not present and a DHCP option is present in the DHCP Renew packet as taught by Juniper. One of ordinary skill in the art would have been motivated to combine configuring the relay agent to add its IP address and VNI to option 82 of the DHCP Renew packet when a gateway address is not present and a DHCP option is present in the DHCP Renew packet to prevent the relay agent from dropping the DHCP Renew packet (Juniper § “Enable Processing of Untrusted Packets so Option 82 Information Can Be Used”).”
Regarding Claim 2, the combination of Chari, Hooda and Juniper discloses all of the limitations of Claim 1.
Additionally, Chari discloses “receiving the acknowledgment from a second router, wherein the second router is positioned between the first router and the remote DHCP server (Chari fig. 10 and paragraphs 44 and 188: access node 1021 receives the DHCP ACK from a home gateway, i.e., a second router, which is positioned in the network path between the access node and the DHCP server).”
Regarding Claim 4, the combination of Chari, Hooda and Juniper discloses all of the limitations of Claim 1.
Additionally, Chari discloses “wherein the remote DHCP server and the local device have a different subnet (Chari fig. 10 and paragraphs 92 and 186: "FIG. 10 shows a mesh network in which DHCP packets can be routed between subnets." – While not explicitly stated, it is readily understood by one of ordinary skill in the art that the client device and DHCP server are located on different subnets).”
Regarding Claim 5, the combination of Chari, Hooda and Juniper discloses all of the limitations of Claim 1.
Additionally, Hooda discloses “wherein the DHCP option represents option 82 in the DHCP renewal request (Hooda figs. 1 and 2 and paragraphs 20 and 22-24: the address of the first network device and the VNI of first local subnet are added to the DHCP Option 82 field of the DHCP request).”
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the method of Chari to add the VNI of a first local subnet to a the relay agent information option field of the DHCP Renew packet as taught by Hooda for the reasons set forth in the rejection of Claim 1.
Regarding Claim 8, Chari discloses “A first router (Chari fig. 10 and paragraphs 40 and 186: access node 1021, which may be a router or any other networking device capable of attachment to a client) comprising:
Intercepting a DHCP renewal request communicated by a local device as a unicast packet to a remote DHCP server (Chari fig. 10 and paragraphs 40 and 186-187: DHCP relay agent on Node N, e.g., access node 1021, intercepts a DHCP Renew packet issued by a client device – while not explicitly stated, sending of the DHCP Renew packet as a unicast packet is inferred, see RFC 2131), wherein the first router is one of a plurality of routers positioned between the local device and the remote DHCP server and wherein the plurality of routers form a mesh network (Chari fig. 10 and paragraphs 28-32, 40, 44 and 186: access node 1021 and foreign gateway 1032 are part of a wireless mesh network and reside in the network path between the client device and home DHCP server 1010);”
“... adding, by the first router, an internet protocol IP address of the first router... to the DHCP renewal request... (Chari fig. 10 and paragraph 187: access node 1021 sets the GIADDR field, i.e., the gateway address, in the DCHP Renew packet to its IP address);
forwarding, by the first router, the DHCP renewal request from the first router to the remote DHCP server (Chari fig. 10 and paragraphs 187: access node 1021 forwards the DHCP Renew packet towards home DHCP server 1010 via foreign gateway 1032);
receiving, by the first router, an acknowledgment communicated by the remote DHCP server, wherein the acknowledgment comprises the IP address of the first router (Chari fig. 10 and paragraph 188: the gateway sets the GIADDR field of the DHCP Ack packet issued by home DHCP server 1010 to the IP address of access node 1021 and unicasts the DCHP Ack packet to access node 1021); and
forwarding, by the first router, the acknowledgment to the local device (Chari fig. 10 and paragraph 188: access node 1021 receives the DHCP ACK packet and relays it to the client device).”
However, while Chari discloses that the access node implementing the DHCP relay agent may be a router (Chari paragraph 40) and further discloses that the access node sets the GIADDR field in the DHCP renew request (Chari fig. 10 and paragraph 187), Chari does not explicitly disclose the access node comprising “one or more processors; and
one or more computer-readable non-transitory storage media coupled to the one or more processors that stores instructions operable when executed by the one or more processors to cause the first router to perform operations...” and
“adding an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device (emphasis added)”.
In the same field of endeavor, Hooda discloses implementing the first network device using a computing device comprising a processor and memory (Hooda fig. 3 and paragraph 31) and further discloses adding, by a DHCP relay agent of a first network device, the IP address of the first network device and a virtual network identifier (VNI) into option 82 of a DHCP request received from a client device (Hooda figs. 1 and 2 and paragraphs 20 and 22-24: the relay agent on first network device 114 adds the address of the first network device and the VNI of first local subnet 106a to the DHCP Option 82 field of a DHCP request received from first client device 120).”
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the access node of Chari to add the VNI of a first local subnet to a the relay agent information option field of the DHCP Renew packet as taught by Hooda. One of ordinary skill in the art would have been motivated to combine adding the VNI of a first local subnet to a the relay agent information option field of the DHCP Renew packet to ensure the response from the DHCP server is routed back to the first network device (Hooda paragraph 20).
However, while Hooda discloses adding, by a DHCP relay agent of a first network device, the IP address of the first network device and a virtual network identifier (VNI) into option 82 of a DHCP request received from a client device (Hooda paragraphs 20 and 22-24), the combination of Chari and Hooda does not explicitly disclose “determining if a gateway address and a DHCP option are present in the DHCP renewal request;
in response to determining, by the first router, that the gateway address is not present in the DHCP renewal request and the DHCP option is present in the DHCP renewal request, adding, by the first router, an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device (emphasis added)”.
In the same field of endeavor, Juniper discloses configuring the DHCP relay agent to process DHCP client packets, e.g. replacing option 82 values in the DHCP packet, when the gateway address is not present and option 82 information is set (Juniper § “Overriding Option 82 Information” and “Enable Processing of Untrusted Packets so Option 82 Information Can Be Used”: “You can override this behavior and specify that the DHCP relay agent process DHCP client packets that have a giaddr of 0 (zero) and contain option 82 information.” – while not explicitly stated, a determination by the DHCP relay agent that the gateway address (giaddr) is not present and the option 82 information is present is inferred).
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the access node of Chari, as modified by Hooda, to configure the relay agent to add its IP address and VNI to option 82 of the DHCP Renew packet when a gateway address is not present and a DHCP option is present in the DHCP Renew packet as taught by Juniper. One of ordinary skill in the art would have been motivated to combine configuring the relay agent to add its IP address and VNI to option 82 of the DHCP Renew packet when a gateway address is not present and a DHCP option is present in the DHCP Renew packet to prevent the relay agent from dropping the DHCP Renew packet (Juniper § “Enable Processing of Untrusted Packets so Option 82 Information Can Be Used”).”
Insofar as it recites similar claim elements, Claim 9 is rejected for substantially the same reasons presented above with respect to Claim 2.
Insofar as it recites similar claim elements, Claim 11 is rejected for substantially the same reasons presented above with respect to Claim 4.
Insofar as it recites similar claim elements, Claim 12 is rejected for substantially the same reasons presented above with respect to Claim 5.
Regarding Claim 15, Chari discloses “intercepting, by a first router, a DHCP renewal request communicated by a local device as a unicast packet to a remote DHCP server (Chari fig. 10 and paragraphs 40 and 186-187: DHCP relay agent on node N such as access node 1021, i.e., a first router, intercepts a DHCP Renew packet issued by a client device), wherein the first router is one of a plurality of routers positioned between the local device and the remote DHCP server and wherein the plurality of routers form a mesh network (Chari fig. 10 and paragraphs 28-32, 40, 44 and 186: access node 1021 and foreign gateway 1032 are part of a wireless mesh network and reside in the network path between the client device and home DHCP server 1010);” and
“...adding, by the first router, an internet protocol (IP) address of the first router... to the DHCP renewal request... (Chari fig. 10 and paragraph 187: access node 1021 sets the GIADDR field, i.e., the gateway address, in the DCHP Renew packet to its IP address);
forwarding, by the first router, the DHCP renewal request from the first router to the remote DHCP server (Chari fig. 10 and paragraphs 187: access node 1021 forwards the DHCP Renew packet towards home DHCP server 1010 via foreign gateway 1032);
receiving, by the first router, an acknowledgment communicated by the remote DHCP server, wherein the acknowledgment comprises the IP address of the first router (Chari fig. 10 and paragraph 188: the gateway sets the GIADDR field of the DHCP Ack packet issued by home DHCP server 1010 to the IP address of access node 1021 and unicasts the DCHP Ack packet to access node 1021); and
forwarding, by the first router, the acknowledgment to the local device (Chari fig. 10 and paragraph 188: access node 1021 receives the DHCP ACK packet and relays it to the client device).”
However, while Chari discloses that the access node implementing the DHCP relay agent may be a router (Chari paragraph 40) and further discloses that the access node sets the GIADDR field in the DHCP renew request (Chari fig. 10 and paragraph 187), Chari does not explicitly disclose “One or more computer-readable non-transitory storage media embodying instructions that, when executed by a processor, cause the processor to perform operations...” and
“adding, by the first router, an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device (emphasis added)”.
In the same field of endeavor, Hooda discloses computer readable storage media comprising instructions for executing a computing process (Hooda fig. 3 and paragraphs 31-34) and further discloses adding, by a DHCP relay agent of a first network device, the IP address of the first network device and a virtual network identifier (VNI) into option 82 of a DHCP request received from a client device (Hooda figs. 1 and 2 and paragraphs 20 and 22-24: the relay agent on first network device 114 adds the address of the first network device and the VNI of first local subnet 106a to the DHCP Option 82 field of a DHCP request received from first client device 120).”
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the access node of Chari to add the VNI of a first local subnet to a the relay agent information option field of the DHCP Renew packet as taught by Hooda. One of ordinary skill in the art would have been motivated to combine adding the VNI of a first local subnet to a the relay agent information option field of the DHCP Renew packet to ensure the response from the DHCP server is routed back to the first network device (Hooda paragraph 20).
However, while Hooda discloses adding, by a DHCP relay agent of a first network device, the IP address of the first network device and a virtual network identifier (VNI) into option 82 of a DHCP request received from a client device (Hooda paragraphs 20 and 22-24), the combination of Chari and Hooda does not explicitly disclose “determining if a gateway address and a DHCP option are present in the DHCP renewal request;
in response to determining, by the first router, that the gateway address is not present in the DHCP renewal request and the DHCP option is present in the DHCP renewal request, adding, by the first router, an internet protocol (IP) address of the first router and the DHCP option to the DHCP renewal request, wherein the DHCP option identifies a virtual network identifier (VNI) associated with the local device (emphasis added)”.
In the same field of endeavor, Juniper discloses configuring the DHCP relay agent to process DHCP client packets, e.g. replacing option 82 values in the DHCP packet, when the gateway address is not present and option 82 information is set (Juniper § “Overriding Option 82 Information” and “Enable Processing of Untrusted Packets so Option 82 Information Can Be Used”: “You can override this behavior and specify that the DHCP relay agent process DHCP client packets that have a giaddr of 0 (zero) and contain option 82 information.” – while not explicitly stated, a determination by the DHCP relay agent that the gateway address (giaddr) is not present and the option 82 information is present is inferred).
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the access node of Chari, as modified by Hooda, to configure the relay agent to add its IP address and VNI to option 82 of the DHCP Renew packet when a gateway address is not present and a DHCP option is present in the DHCP Renew packet as taught by Juniper. One of ordinary skill in the art would have been motivated to combine configuring the relay agent to add its IP address and VNI to option 82 of the DHCP Renew packet when a gateway address is not present and a DHCP option is present in the DHCP Renew packet to prevent the relay agent from dropping the DHCP Renew packet (Juniper § “Enable Processing of Untrusted Packets so Option 82 Information Can Be Used”).”
Insofar as it recites similar claim elements, Claim 16 is rejected for substantially the same reasons presented above with respect to Claim 2.
Insofar as it recites similar claim elements, Claim 18 is rejected for substantially the same reasons presented above with respect to Claim 5.
Claims 3, 7, 10, 14, 17 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Chari, Hooda and Juniper in view of the article by ldanny, titled “DHCP in the Fabric”, hereby “ldanny”.
Regarding Claim 3, the combination of Chari, Hooda and Juniper discloses all of the limitations of Claim 1.
However, while Chari discloses that the access node, i.e., the first router, receives the DHCP ACK from the gateway, i.e., a second router located between the access node and the DHCP server, as a unicast transmission (Chari paragraphs 44 and 188), the combination of Chari, Hooda and Juniper does not explicitly disclose “receiving the acknowledgment as a unicast packet from a fusion router, wherein the fusion router is positioned between the first router and the remote DHCP server (emphasis added).”
In the same field of endeavor, ldanny discloses a fusion router that resides in the network path between an edge router, i.e., a first router, and a remote DHCP server (ldanny § “DHCP Flow in The Fabric”: see figure on page 5 of PDF illustrating edge router “E”, fusion router, and DHCP server).
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the method of Chari, as modified by Hooda and Juniper, to utilize a fusion router located between the access node and the remote DHCP server as taught by ldanny because doing so constitutes a simple substitution of one known element (a gateway) for another (a fusion router) to obtain predictable and desirable results (relaying of DHCP messages between the access node and the DHCP server). See KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 (U.S. 2007).
Regarding Claim 7, the combination of Chari, Hooda and Juniper discloses all of the limitations of Claim 1.
Additionally, Chari discloses wherein “the first router is an edge node of the mesh network (Chari fig. 10 and paragraphs 31 and 40: access nodes, such as access node 1021, provide a point of attachment of a client with the wireless mesh network, i.e., are edge nodes of the mesh network).”
However, while Chari discloses that the access nodes and gateways are part of the wireless mesh network (Chari paragraph 31), the combination of Chari, Hooda and Juniper does not explicitly disclose wherein “the mesh network is a software-defined access (SDA) network.”
In the same field of endeavor, ldanny discloses a software-defined-access (SDA fabric, i.e., mesh network, comprising a plurality of edge and border devices (ldanny § “DHCP Flow in The Fabric”: see figure on page 5 of PDF illustrating SDA fabric comprising edge device “E” and border device “B”).”
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the method of Chari, as modified by Hooda and Juniper, to implement a software-defined access (SDA) fabric as taught by ldanny because doing so constitutes a simple substitution of one known element (a wireless mesh network ) for another (an SDA fabric) to obtain predictable and desirable results (enabling communication between client devices and the external network). See KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 (U.S. 2007).
Insofar as it recites similar claim elements, Claim 10 is rejected for substantially the same reasons presented above with respect to Claim 3.
Insofar as it recites similar claim elements, Claim 14 is rejected for substantially the same reasons presented above with respect to Claim 7.
Insofar as it recites similar claim elements, Claim 17 is rejected for substantially the same reasons presented above with respect to Claim 3.
Insofar as it recites similar claim elements, Claim 20 is rejected for substantially the same reasons presented above with respect to Claim 7.
Claims 6, 13 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Chari, Hooda and Juniper in view of the Droms, RFC 2131 titled “Dynamic Host Configuration Protocol (DHCP)”.
Regarding Claim 3, the combination of Chari, Hooda and Juniper discloses all of the limitations of Claim 1.
However, while Chari discloses the access node, i.e., the first router, receiving the DHCP ACK unicast from the gateway and relaying the DHCP ACK to the client device (Chari paragraph 188), the combination of Chari, Hooda and Juniper does not explicitly disclose “wherein the first router receives the acknowledgment as a unicast message and forwards the acknowledgment to the local device as a broadcast (emphasis added).”
In the same field of endeavor, Droms discloses that a DHCP relay agent may broadcast a DHCP ACK received from the DHCP server to the DHCP client (Droms § “4.1 Constructing and sending DHCP messages”: “A server or relay agent sending or relaying a DHCP message directly to a DHCP client (i.e., not to a relay agent specified in the ’giaddr’ field) SHOULD examine the BROADCAST bit in the ’flags’ field. If this bit is set to 1, the DHCP message SHOULD be sent as an IP broadcast using an IP broadcast address (preferably 0xffffffff) as the IP destination address and the link-layer broadcast address as the link-layer destination address.”).”
It would have been obvious to one of ordinary skill in the art at the time of the effective filing to modify the method of Chari, as modified by Hooda and Juniper, to broadcast the DHCP ACK from the access node to the client device as taught by Droms. One of ordinary skill in the art would have been motivated to combine broadcasting the DHCP ACK from the access node to the client device when unicasting the DHCP ACK is not possible due to client configuration (Droms § “4.1 Constructing and sending DHCP messages”).
Insofar as it recites similar claim elements, Claim 13 is rejected for substantially the same reasons presented above with respect to Claim 6.
Insofar as it recites similar claim elements, Claim 19 is rejected for substantially the same reasons presented above with respect to Claim 6.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Gandhewar et al., Pub. No. US 2010/0191839 A1, discloses techniques for synchronizing resource bindings within computer networks wherein a DHCP relay device modifies a DHCP discover message received from a DHCP client device by adding a VLAN identifier to the option 82 field;
Kapadia et al., Pat. No. US 9,438,475 B1, discloses techniques for providing enhanced address allocation services in a network wherein a switch inserts the loopback address into the giAddr field and add subnet information of a virtual machine in the option-82 field of a DHCP request intercepted from a host device; and
Pani et al., Pub. No. US 2015/0124823 A1, discloses a system and method for DHCP functionality in an overlay network wherein a switch, operating as a DHCP relay agent, inserts its IP address and a VNID into option 82 of a DHCP request received from a client.
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/WILLIAM C MCBETH/Examiner, Art Unit 2449
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