FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION

“Dynamic detection of configuration mismatch on 802.3AD enabled Link aggregation ports”
APPLICANTS:
Name Nationality Address
Alcatel Lucent France Alcatel-Lucent , 3 av. Octave Gréard
75007 Paris, France

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

TECHNICAL FIELD
[001] The present invention relates to communication protocols and, more particularly, to the 802.3ad communication protocol.

BACKGROUND
[002] 802.3ad (Link Aggregation Control Protocol (LACP)) describes using multiple network cables/ports in parallel to increase the link speed beyond the limits of any one single cable or port, and to increase the redundancy for higher availability. LACP was proposed to overcome bandwidth limitations in existing networking ports by providing a method to control the bundling of several physical ports together to form a single logical channel. LACP allows a network device to negotiate an automatic bundling of links by sending LACP packets to the peer (directly connected device that also implements LACP). LACP works by sending frames down all links that have the protocol enabled. If it finds a device on the other end of the link that also has LACP enabled, it will also independently send frames along the same links enabling the two units to detect multiple links between themselves and then combine them into a single aggregated link.
[003] LACP assumes that all the links in an aggregated link have the same speed. However, in practice, the links in an aggregated link may not be of the same speed. This can result in an error in the aggregated link, which may result in a loss in data packets, when they are sent across the aggregated link. For example, consider two links, one of 100 Mbps and the second one of 10 Mbps, which is aggregated to form a single aggregated link. As per LACP, the speed of the aggregated link may be assumed to be 2x100 Mbps, i.e., 200 Mbps, but in reality the speed of the aggregated link is 100+10=110Mbps. So, when data packets which require a speed of 200 Mbps are sent across the aggregated link, some of the packets may be lost due to the mismatch between the actual speed of the aggregated link and the perceived speed of the aggregated link.

SUMMARY
[004] In view of the foregoing, an embodiment herein provides a method for adding a first link in a first device and a second link in a second device to an aggregated link in a communication network, the method comprising of the first device comparing speed of the first link to speed of the second link, wherein the first device obtains speed of the second link using a protocol data unit; and the first device adding the first link and the second link to the aggregated link, if speed of the first link matches speed of the second link. The method further comprises steps of the first device checking if constraints have been set on speed of the first link and the second link; the first device checking if constraints set on speed of the first link and the second link are satisfied, which may be set using a CLI/SNMP command, if constraints have been set on speed of the first link and the second link; and the first device adding the first link and the second link to the aggregated link, if constraints set on speed of the first link and the second link are satisfied. The first device may send a notification to a network management system, if speed of the first link does not match the speed of the second link.
[005] Embodiments herein further disclose a communication network comprising of a first device with a first link and a second device with a second link and further comprising at least one means adapted for comparing speed of the first link to speed of the second link; and adding the first link and the second link to an aggregated link, if speed of the first link matches speed of the second link. The communication network is configured for enabling the first device to obtain speed of the second link using a protocol data unit. The communication network further comprises at least one means configured for checking if constraints have been set on speed of the first link and the second link; checking if constraints set on speed of the first link and the second link are satisfied, if constraints have been set on speed of the first link and the second link; and adding the first link and the second link to the aggregated link, if constraints set on speed of the first link and the second link are satisfied. The communication network is configured for enabling constraints to be set on speed of the first link and the second link using a CLI/SNMP command. The network is configured for enabling the first device to send a notification to a network management system, if speed of the first link does not match the speed of the second link.
[006] Embodiments herein further disclose a device with a first link in a communication network, the device further comprising at least one means adapted for comparing speed of the first link to speed of a second link in a second device; and adding the first link and the second link to an aggregated link, if speed of the first link matches speed of the second link. The device is configured for obtaining speed of the second link using a protocol data unit. The device is configured for checking if constraints have been set on speed of the first link and the second link; checking if constraints set on speed of the first link and the second link are satisfied, if constraints have been set on speed of the first link and the second link; and adding the first link and the second link to the aggregated link, if constraints set on speed of the first link and the second link are satisfied. The device is configured for enabling constraints to be set on speed of the first link and the second link using a CLI/SNMP command. The device is configured for enabling the device to send a notification to a network management system, if speed of the first link does not match the speed of the second link.
[007] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES
[008] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[009] FIG. 1 depicts a network, according to embodiments as disclosed herein;
[0010] FIGs.2 and 3 depict PDUs, according to embodiments as disclosed herein;
[0011] FIGs. 4 and 5 are exemplary implementations, according to embodiments as disclosed herein.
[0012] FIG. 5 depicts a device, according to embodiments as disclosed herein;
[0013] FIGs. 7a and 7b depict flowcharts, according to embodiments as disclosed herein.

DETAILED DESCRIPTION OF EMBODIMENTS
[0014] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0015] The embodiments herein disclose a method and system to dynamically detect mismatches in LACP links and a mechanism to raise an alert on detecting the mismatch. Referring now to the drawings, and more particularly to FIGS. 1 through 7, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0016] FIG. 1 depicts a network, according to embodiments as disclosed herein. The network, as depicted, comprises of a plurality of devices 101, 102 and a Network Management System (NMS) 103. Each of the devices comprise of a plurality of communication links. The devices, device-A 101 and device-B 101 comprise of 4 links each; A1, A2, A3, A4 in device-A 101 and B1, B2, B3 and B4 in device-B 102. Both the devices 101, 102 are connected to the NMS 103 using a suitable connection means. Device-A 101 may initiate formation of an aggregated link between the links of device-B 102. The device-A 101 inserts the speed of A1 into a reserved field in the protocol data unit (PDU). The speed of A1 may be inserted into a reserved byte present in the PDU hereinafter referred to as actor_operspeed, as depicted in FIG. 2. The device-A 101 sends the PDU to the device-B 102. The device-B 102 moves the speed of A1 from the actor_operspeed field into a second reserved byte present in the PDU hereinafter referred to as partner_operspeed and inserts the speed of B1 into the actor_operspeed field in the PDU, as depicted in FIG. 3. The device-B 102 sends the PDU to the device-A 101.
[0017] Device-A 101 on receiving the PDU from Device-B 102 checks if the speeds of A1 and B1 match. The device-A 101 may check if the speeds of A1 and B1 match by checking the values present in the actor_operspeed and partner_operspeed fields. If the speeds of A1 and B1 do not match, then the device-A 101 sends an appropriate notification to the NMS 103. The device-A 101 may then obtain the speeds of all the links of device-B 102 and compares the corresponding speeds of the links.
[0018] Further if the speeds of a pair of links match, the device-A 101 may check for any conditions set on the speed of the link. An appropriately authorized user of the network may set the speed of the link using a CLI/SNMP command.
lacp linkagg <linkagg-id> aggregator speed {none/strict/atleast} speed in units
[0019] Conditions may be imposed on the links to be aggregated using the above command.
lacp linkagg <linkagg-id> aggregator speed none
[0020] The above command indicates that the speed of the links is not to be taken into account while aggregating the links. If the speeds of the links match, then device-A 101 may aggregate the links. FIG. 1 depicts a scenario where the speed of the links is not taken into account while aggregating the links. If the speeds of the links A1, A2, A3 and A4 match with B1, B2, B3 and B4 respectively, then device-A 101 may add them into the aggregated link.
lacp linkagg <linkagg-id> aggregator speed strict A Mbps
[0021] The above command indicates that the speed of the links has to be A Mbps. If the speed of A1 and B1 match and is exactly A Mbps, then only will the device-A 101 may add A1 and B1 to the aggregated link. If the speeds of A1 and B1 are not A Mbps (may be less than A Mbps or greater than A Mbps), then device-A 101 may not add A1 and B1 to the aggregated link. FIG. 4 and 5 depict scenarios where the speed of the links is set strictly.
lacp linkagg <linkagg-id> aggregator speed strict 1Gbps
[0022] In FIG. 4, the speed of each of the individual links has to be 1 Gbps. Here, the speeds of A1, A2, B1 and B2 are 1 Gbps each, while the speeds of A3 and B3 are 100 Mbps each and the speeds of A4 and B4 are 2 Gbps each. As the speed of the individual links has to be 1 Gbps, the device-A 101 adds A1, B1, A2 and B2 to the aggregated link of speed 2 Gbps. As the speed of A3 and B3 are less than 1 Gbps, the device-A 101 does not add them into the aggregate link. Similarly, as the speed of A4 and B4 are greater than 1 Gbps, the device-A 101 does not add them into the aggregate link.
lacp linkagg <linkagg-id> aggregator speed atleast A Mbps
[0023] The above command indicates that the speed of the links has to be at least A Mbps. If the speed of A1 and B1 are the same and the speed of A1 and B1 is A Mbps or greater than A Mbps, then only will the device-A 101 may add A1 and B1 to the aggregated link. If the speeds of A1 and B1 are less than A Mbps, then device-A 101 may not add A1 and B1 to the aggregated link.
lacp linkagg <linkagg-id> aggregator speed atleast 100 Mbps
[0024] The above command indicates that the speed of the links has to be at least 100 Mbps. In FIG. 5, the speeds of A1, A2, B1 and B2 are 1 Gbps each, while the speeds of A3 and B3 are 100 Mbps each and the speeds of A4 and B4 are 10 Mbps each. As the speed of the individual links has to be at least 100 Mbps, the device-A 101 adds A1, B1, A2, B2, A3 and B3 to the aggregated link with a speed of 2.1 Gbps. As the speed of A4 and B4 are less than 100 Mbps, the device-A 101 does not add them to the aggregated link.
[0025] In another embodiment herein, there may not be constraints specified on the links. The format of the CLI/SNMP command is only exemplary and any other suitable format may be used.
[0026] FIG. 6 depicts a device, according to embodiments as disclosed herein. The device 101, 102 may be any device present in the network and having ports for communication and capable of using LACP. The device 101, 102 as depicted comprises of a controller 601, a transceiver 602, a plurality of links 603 and a memory 604. The controller 601 may initiate formation of an aggregated link between a link 603 and a link in another device present in the same network. The controller 601 inserts the speed of A1 into a reserved field in the protocol data unit (PDU). The speed of link 203 may be inserted into a reserved byte present in the PDU hereinafter referred to as actor_operspeed, as depicted in FIG. 2. The controller 601 sends the PDU to the other device using the transceiver 602. On receiving the PDU from the other device via the transceiver 602, the controller 601 checks if the speeds of link 203 and the other link match. The controller 601 may check if the speeds of link 603 and the other link match by checking the values present in the actor_operspeed and partner_operspeed fields. If the speeds of link 603 and the other link do not match, then the controller 601 sends an appropriate notification to the NMS 103 using the transceiver 602.
[0027] Further if the speeds of link 603 and the other link match, the controller 601 may check for any conditions set on the speed of the link. An appropriately authorized user of the network may set the speed of the link using the CLI/SNMP command and the values may be stored in the memory 604. If the speed of the links is not to be taken into account while aggregating the links, the controller 601 adds the link 603 and the other link to the aggregated link. If the speed of the links has been set to a specific value, the controller 601 checks if the speed of the link is of the specific value. If the speed of the link is of the specified value, then the controller 601 adds the link 603 and the other link to the aggregated link. If the speed of the link is not of the specified value, then the controller 601 does not aggregate the links and sends an appropriate notification to the NMS 103. If the speed of the links has been set to be at least a specific value, the controller 601 checks if the speed of the link is at least the specific value. If the speed of the link is at least the specified value, then the controller 601 adds the link 603 and the other link to form the aggregated link. If the speed of the link is less than the specified value, then the controller 601 does not add the links to the aggregated link and sends an appropriate notification to the NMS 103.
[0028] FIG. 7 depicts a flowchart, according to embodiments as disclosed herein. When device-A 101 may initiate formation of an aggregated link between links A1 and B1 of device-B 102, device-A 101 inserts (701) the speed of A1 into a reserved field in the protocol data unit (PDU). The speed of A1 may be inserted into a reserved byte present in the PDU referred to as actor_operspeed, as depicted in FIG. 2. The device-A 101 sends (702) the PDU to the device-B 102. The device-B 102 inserts (703) the speed of B1 into the PDU. The device-B 102 moves the speed of A1 from the actor_operspeed field into a second reserved byte present in the PDU hereinafter referred to as partner_operspeed and inserts the speed of B1 into the actor_operspeed field in the PDU,, as depicted in FIG. 3. The device-B 102 sends (704) the PDU to the device-A 101. On receiving the PDU from Device-B 102, the Device-A 101 checks (705) if the speeds of A1 and B1 match. The device-A 101 may check if the speeds of A1 and B1 match by checking the values present in the actor_operspeed and partner_operspeed fields. If the speeds of A1 and B1 do not match, then the device-A 101 sends (706) an appropriate notification to the NMS 103. If the speeds of A1 and B1 match, the device-A 101 checks (707) for the CLI/SNMP command and further checks (708) for any conditions set on the speed of the link using the CLI/SNMP command. If the CLI/SNMP command is not present or there are no constraints set on the speed of the links, then the device-A 101 adds (711) A1 and B1 to the aggregated link. If there are constraints set on the speed of the links, then the device-A 101 checks (709) if the speeds of A1 and B1 satisfy the constraints. If the speeds of A1 and B1 do not satisfy the constraints, then the device-A 101 does (710) not add the links to the aggregated link and informs (706) the NMS 103 of the mismatch. If the speeds of A1 and B1 satisfy the constraints, then the device-A 101 adds (711) A1 and B1 to the aggregated link. The various actions in method 700 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 7 may be omitted.
[0029] Though embodiments herein disclose devices having four links and equal number of links, it may be obvious to a person of ordinary skill in the art that the embodiments as disclosed above may be used for devices with any number of links and for forming aggregated links between devices with unequal number of links.
[0030] Embodiments disclosed herein may be used to dynamically detect mismatches in LACP links and a mechanism to raise an alert on detecting the mismatch, hereby maintaining the Service Level Agreement (SLA) for the users of the network.
[0031] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the network elements. The network elements shown in Figs. 1 and 6 include blocks which can be at least one of a hardware device, or a combination of hardware device and software module.
[0032] The embodiment disclosed herein specifies a mechanism to dynamically detect mismatches in LACP links and a mechanism to raise an alert on detecting the mismatch. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in a preferred embodiment through or together with a code written in e.g. Very high speed integrated circuit Hardware Description Language (VHDL) or any other coding language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of device which can be programmed including e.g. any kind of computer like a server or a personal computer, or the like, or any combination thereof, e.g. one processor and two FPGAs. The device may also include means which could be e.g. hardware means like e.g. an ASIC, or a combination of hardware and software means, e.g. an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. The method embodiments described herein could be implemented in pure hardware or partly in hardware and partly in software. Alternatively, the invention may be implemented on different hardware devices, e.g. using a plurality of CPUs.
[0033] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the claims as described herein.

CLAIMS
What is claimed is:
1. A method for adding a first link in a first device and a second link in a second device to an aggregated link in a communication network, said method comprising of
Said first device comparing speed of said first link to speed of said second link; and
Said first device adding said first link and said second link to said aggregated link, if speed of said first link matches speed of said second link.

2. The method, as claimed in claim 1, wherein said first device obtains speed of said second link using a protocol data unit.

3. The method, as claimed in claim 1, wherein said method further comprises steps of
Said first device checking if constraints have been set on speed of said first link and said second link;
Said first device checking if constraints set on speed of said first link and said second link are satisfied, if constraints have been set on speed of said first link and said second link; and
Said first device adding said first link and said second link to said aggregated link, if constraints set on speed of said first link and said second link are satisfied.

4. The method, as claimed in claim 3, wherein constraints are set on speed of said first link and said second link using a CLI/SNMP command.

5. The method, as claimed in claim 1, wherein said first device sends a notification to a network management system, if speed of said first link does not match the speed of said second link.

6. A communication network comprising of a first device with a first link and a second device with a second link and further comprising at least one means adapted for
comparing speed of said first link to speed of said second link; and
adding said first link and said second link to an aggregated link, if speed of said first link matches speed of said second link.

7. The communication network, as claimed in claim 6, wherein said communication network is configured for enabling said first device to obtain speed of said second link using a protocol data unit.

8. The communication network, as claimed in claim 6, wherein said communication network further comprises at least one means configured for
checking if constraints have been set on speed of said first link and said second link;
checking if constraints set on speed of said first link and said second link are satisfied, if constraints have been set on speed of said first link and said second link; and
adding said first link and said second link to said aggregated link, if constraints set on speed of said first link and said second link are satisfied.

9. The communication network, as claimed in claim 3, wherein said communication network is configured for enabling constraints to be set on speed of said first link and said second link using a CLI/SNMP command.

10. The communication network, as claimed in claim 6, wherein said communication network is configured for enabling said first device to send a notification to a network management system, if speed of said first link does not match the speed of said second link.

11. A device with a first link in a communication network, said device further comprising at least one means adapted for
comparing speed of said first link to speed of a second link in a second device; and
adding said first link and said second link to an aggregated link, if speed of said first link matches speed of said second link.

12. The device, as claimed in claim 11, wherein said device is configured for obtaining speed of said second link using a protocol data unit.

13. The device, as claimed in claim 11, wherein said device is configured for
checking if constraints have been set on speed of said first link and said second link;
checking if constraints set on speed of said first link and said second link are satisfied, if constraints have been set on speed of said first link and said second link; and
adding said first link and said second link to said aggregated link, if constraints set on speed of said first link and said second link are satisfied.

14. The device, as claimed in claim 13, wherein said device is configured for enabling constraints to be set on speed of said first link and said second link using a CLI/SNMP command.

15. The device, as claimed in claim 13, wherein said device is configured for enabling said device to send a notification to a network management system, if speed of said first link does not match the speed of said second link.

Dated this 24th November 2010

Dr. Kalyan Chakravarthy
Patent Agent

ABSTRACT
Dynamic detection of configuration mismatch on 802.3AD enabled Link aggregation ports. The present invention relates to communication protocols and, more particularly, to the 802.3ad communication protocol. Embodiments disclosed herein may be used to dynamically detect mismatches in LACP links and a mechanism to raise an alert on detecting the mismatch, hereby maintaining the Service Level Agreement (SLA) for the users of the network by enabling the devices to exchange the speed of each of the links, before linking up. If the speeds of the links match, then the links are aggregated to form an aggregated link. If the speeds of the links do not match, then an alert is raised and send to the NMS. Embodiments further disclose additional constraints that may be laid on the speed of the links.

FIG. 1