Fast connection protection in a virtual local area network based stack environment
First Claim
1. A method of providing connection protection in a Virtual Local Area Network (VLAN) based local edge stack, said method comprising the steps of:
- provisioning a main VLAN for a connection between a local edge switch and a remote switch;
provisioning an alternative VLAN for said connection in each edge switch in said stack;
switching, at edge switches on either side of a detected failed link, all protected traffic going through said failed link to said alternative VLAN, wherein if said connection begins on an edge switch that detected said link failure, switching protected traffic destined for said failed link to said alternative VLAN in response to detection of said link failure, and wherein if said connection does not begin on an edge switch that detected said link failure, modifying packets received over a network port on said main VLAN to said alternative VLAN and returning said modified packets over the same network port they were received over; and
setting a flag in Hello packets on the edge switch that detected said failure before forwarding to said alternative VLAN, said flag for informing an edge switch at an opposite end of said connection to switch to said alternative VLAN.
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Accused Products
Abstract
A fast protection mechanism capable of maintaining end-to-end and fast local protection on the order of sub 50 ms for both VLAN only based connections and for connections that are based partially on VLAN technology and partially on MPLS technology. The present invention is suitable for use edge switches configured in a stack or ring topology. The NMS provisions both the main and alternative VLANs in each edge switch in the stack portions of the network. When a link failure occurs, the edge switches on either end of the failed link immediately switch all protected traffic going through that link to the alternative VLAN. The packets are then returned on the links over which they were received. Hello messages are used to signal the remote end that a link failure has occurred and that protected traffic must be switched to the main or alternative VLAN in accordance with the VLAN the Hello message was received on.
152 Citations
47 Claims
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1. A method of providing connection protection in a Virtual Local Area Network (VLAN) based local edge stack, said method comprising the steps of:
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provisioning a main VLAN for a connection between a local edge switch and a remote switch; provisioning an alternative VLAN for said connection in each edge switch in said stack; switching, at edge switches on either side of a detected failed link, all protected traffic going through said failed link to said alternative VLAN, wherein if said connection begins on an edge switch that detected said link failure, switching protected traffic destined for said failed link to said alternative VLAN in response to detection of said link failure, and wherein if said connection does not begin on an edge switch that detected said link failure, modifying packets received over a network port on said main VLAN to said alternative VLAN and returning said modified packets over the same network port they were received over; and setting a flag in Hello packets on the edge switch that detected said failure before forwarding to said alternative VLAN, said flag for informing an edge switch at an opposite end of said connection to switch to said alternative VLAN. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of providing connection protection in a Virtual Local Area Network (VLAN) based stack, said method comprising the steps of:
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provisioning a main VLAN for a connection between a local edge switch and a remote switch; provisioning an alternative VLAN for said connection on each edge switch in said stack; provisioning a Multiprotocol Label Switching (MPLS) bypass tunnel between opposite ends of said stack; switching, at edge switches on either side of a detected failed link, all protected traffic going through said failed link to said alternative VLAN, wherein if said connection begins on an edge switch that detected said link failure, switching protected traffic destined for said failed link to said alternative VLAN in response to detection of said link failure, and wherein if said connection does not begin on an edge switch that detected said link failure, modifying packets received over a network port on said main VLAN to said alternative VLAN and returning said modified packets over the same network port they were received over; setting a flag in Hello packets on the eye switch that detected said failure before forwarding to said alternative VLAN, said flag for informing a remote edge switch to switch to said alternative VLAN; forwarding said protected traffic via said bypass tunnel; and upon reaching the end of said bypass tunnel, forwarding said protected traffic to said alternative VLAN. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method of providing connection protection in a Virtual Local Area Network (VLAN) based stack, said method comprising the steps of:
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provisioning a main VLAN for a connection between a local edge switch and a remote switch; provisioning an alternative VLAN for said connection; if said connection begins on the edge switch that detected a failure, switching protected traffic to said alternative VLAN; if said connection does not begin on the edge switch that detected the failure, changing packets received over a network port on said main VLAN to said alternative VLAN and returning said changed packets over the same network port they were received from; sending an Other Path Down (OPD) indication to a remote edge switch; and switching protected user data to said alternative VLAN upon receipt of an OPD acknowledgement if the edge switch terminates said connection. - View Dependent Claims (34, 35, 36, 37, 38)
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39. A packet processor for use in each edge switch in a Virtual Local Area Network (VLAN) based stack, each edge switch including a plurality of user ports and a plurality of network ports, comprising:
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means for maintaining the status of each link connected to the edge switch; means for maintaining a fast protection flag for each connection indicating whether, in the event of a link failure, packets received tagged with a main VLAN of said connection are to be returned over the network port on which they were received; means for tagging a received packet with an alternative VLAN in the event a link failure occurs and said received packet is for said main VLAN of a connection whereby said fast protection flag is set; and means for setting a flag in said received packets before forwarding to said alternative VLAN if said edge switch detected said link failure, said flag for indicating to a remote edge switch to switch to said alternative VLAN. - View Dependent Claims (40, 41, 42, 43, 44, 45)
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46. A method of providing connection protection in a Virtual Local Area Network (VLAN) network for use on a Multiprotocol Label Switching (MPLS) based core switch, wherein a main VLAN and an alternative VLAN are provisioned for a connection between a local edge switch and a remote edge switch, and wherein an MPLS bypass tunnel is provisioned between opposite ends of a stack to be protected, said method comprising the steps of:
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detecting failure of a link; switching protected traffic destined for said failed link to said alternative VLAN in response to detection or said link failure; setting a flag in packets before forwarding to said alternative VLAN, said flag for indicating to said remote edge switch to switch to said alternative VLAN; and forwarding said protected traffic to said bypass tunnel.
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47. An edge switch in a Virtual Local Area Network (VLAN) based stack, comprising:
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a plurality of user ports for interfacing said edge switch to one or more users; a plurality of network ports for interfacing said edge switch to one or more communication links; packet processing means operative to; maintain the status of each link connected to the edge switch; maintain a fast protection flag for each connection indicating whether, in the event of a link failure, packets received tagged with a main VLAN of said connection are to be returned over the network port on which they were received; tag a received packet with an alternative VLAN in the event a link failure occurs and said received packet is for said main VLAN of a connection whereby said fast protection flag is set; and if said edge switch detected said link failure, setting a flag in said received packets before forwarding to said alternative VLAN, said flag for indicating to a remote edge switch to switch to said alternative VLAN.
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Specification