# US 10,122,616 B2 · Method and apparatus for local path protection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,616 B2 - Document ID: US10122616B2 - Status: Granted - Kind: B2 - Application number: 14/904,238 - Filed: 2013-07-19 - Published: 2016-06-02 - Granted: 2018-11-06 - Earliest claimed: 2013-07-19 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget L M Ericsson (publ) - Inventors: Daniele Ceccarelli; Giulio Bottari; Diego Caviglia - Web page: https://patentgrep.com/patent/US10122616B2 ## CPC - H04L 45/22: {Alternate routing} - H04J 14/0258: {Wavelength identification or labelling} - H04J 14/0275: {using an optical service channel} - H04J 14/0295: {Shared protection at the optical channel (1:1, n:m)} - H04L 45/28: using route fault recovery - H04Q 11/0066: {Provisions for optical burst or packet networks} - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04Q 2011/0016: {using wavelength multiplexing or demultiplexing} - H04Q 2011/0033: {using time division switching} - H04Q 2011/0077: {Labelling aspects, e.g. multiprotocol label switching [MPLS], G-MPLS, MPAS} - H04Q 2011/0081: {Fault tolerance; Redundancy; Recovery; Reconfigurability} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) ## Abstract A method of local path protection in a node on a shared alternative path of a network. The method comprising receiving a signal switched on a primary label switched path (LSP). The signal is switched by lambda-switching or time-division multiplex TDM switching. The method further comprises receiving identification information arranged to identify the signal, and forwarding the signal on the alternative path based on the identification information. ## Claims ### Claim 1 A method of local path protection in a node on a shared alternative path of a network, comprising: receiving a signal that was previously switched on a primary label switched path (LSP), wherein the signal is switched by at least one of lambda-switching and time-division multiplex (TDM) switching; receiving identification information arranged to identify the signal; and forwarding the signal on the shared alternative path, instead of forwarding the signal on the primary LSP, based on the identification information. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein the forwarding the signal on the shared alternative path is based on the identification information and the primary (LSP). ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein the signal is a lambda or a time-division multiplexed data unit. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein the identification information is in a data plane. ### Claim 5 (depends on 1) The method as claimed claim 1, wherein the identification information is configured to identify the primary label switched path at a network level. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein a cross-connection of the node on the shared alternative path is associated with the identification information, such that the cross-connection is selected based on the received identification information. ### Claim 7 (depends on 1) The method as claimed in claim 1, wherein the node of the shared alternative path is pre-configured with cross-connections, and the identification information received with the signal determines which of the cross-connections is used by the node of the shared alternative path to forward the signal on the alternative path. ### Claim 8 (depends on 1) The method as claimed in claim 1, wherein nodes of the shared alternative path are pre-configured by a management plane. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the signal is a time-division multiplexed Optical channel Data Unit (ODU) in an Optical Transport Network (OTN) network. ### Claim 10 (depends on 1) The method as claimed in claim 1, wherein the identification information comprises a quintuple key identifier. ### Claim 11 (depends on 1) The method as claimed in claim 1, wherein the signal is part of a wavelength division multiplexed WDM optical signal. ### Claim 12 A node configured for a shared alternative path of a network, the node comprising: an input interface configured to receive a signal that was previously switched on a primary label switched path (LSP), wherein the signal is switched by at least one of lambda-switching and time-division multiplex TDM switching; an output interface configured to forward the signal on the shared alternative path; and a processor configured to: receive identification information arranged to identify the signal, and select the output interface, instead of an interface configured to forward the signal on the primary LSP, based on the identification information. ### Claim 13 (depends on 12) The node as claimed in claim 12, wherein the node of the alternative path is pre-configured with cross-connections, and wherein the processor is configured to receive the identification information associated with the signal to determine which of the cross-connections is used by the node of the alternative path to forward the signal. ### Claim 14 (depends on 12) The node as claimed in claim 12, further comprising a cross-connection of the node on the shared alternative path is associated with the identification information, such that the cross-connection is selected based on the received identification information. ### Claim 15 (depends on 12) The node as claimed in claim 12, wherein the node of the shared alternative path is pre-configured with cross-connections, and the identification information received with the signal determines which of the cross-connections is used by the node of the shared alternative path to forward the signal. ### Claim 16 A method of local path protection in a node on a primary path of a network, comprising: receiving a signal switched on the primary label switched path (LSP), wherein the signal is switched by at least one of lambda-switching and time-division multiplex TDM switching; determining that the signal is to be sent on an alternative path; and forwarding on the alternative path the signal and identification information arranged to identify the signal, wherein the signal is further to be forwarded, based on the identification information, at a node of an alternative shared path instead of being forwarded on the primary LSP. ### Claim 17 (depends on 16) The method as claimed in claim 16, wherein the forwarding on the alternative path of the signal is based on the identification information and the primary (LSP). ### Claim 18 (depends on 16) The method as claimed in claim 16, wherein the identification information is on a data plane. ### Claim 19 (depends on 16) The method as claimed claim 16, wherein the identification information is configured to identify the primary label switched path at a network level. ### Claim 20 A node configured for a primary path of a network, the node comprising: an input interface configured to receive a signal switched with a label switched path LSP; a processor configured to determine identification information of the signal; and an output interface configured to transmit the signal and identification information on an alternative path, wherein the signal is further to be forwarded, based on the identification information, at a node of an alternative shared path instead of being forwarded on the primary LSP. ### Claim 21 (depends on 20) The node as claimed in claim 20, wherein the node is pre-configured with cross-connections wherein the output interface is configured to transmit identification information associated with the signal to determine which of the cross-connections is used by the node to forward the signal.