# US 7,609,621 B1 · Automatic protection network switching > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,621 B1 - Document ID: US7609621B1 - Status: Granted - Kind: B1 - Application number: 10/776,460 - Filed: 2004-02-10 - Granted: 2009-10-27 - Earliest claimed: 2004-02-10 - Inventors: Sameer Kanagala; Jan Medved; Alex Dadnam - Web page: https://patentgrep.com/patent/US7609621B1 ## CPC - H04L 45/22: {Alternate routing} - H04L 45/28: using route fault recovery - H04J 3/14: Monitoring arrangements {(for SDH/SONET rings H04J3/085)} - H04J 2203/006: Fault tolerance and recovery - 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) ## Abstract A method of protecting a protected link is disclosed. The method includes connecting traffic from a service module to a first physical module having a link layer framer that is connected to a protected egress link. The traffic is connected through the first physical module through a pooling switch to a second physical module that is connected to an alternate egress link. ## Claims ### Claim 1 A method of protecting a protected egress link including: connecting traffic from a service module to a first physical module having a link layer framer that is connected via a link interface of the first physical module to the protected egress link, wherein the link layer framer includes a queue for storing the traffic; and connecting the traffic input to the link interface of the first physical module through a pooling switch to a second physical module that is connected via a link interface of the second physical module to an alternate egress link, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through the link layer framer of the first physical module. ### Claim 2 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the link interface of the first physical module comprises an optical link interface module. ### Claim 3 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the link interface of the second physical module comprises an optical link interface module. ### Claim 4 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the link interface of the first physical module comprises an electrical link interface module. ### Claim 5 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the link interface of the second physical module comprises an electrical link interface module. ### Claim 6 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the first physical module comprises a module that places the traffic in proper form for a pooling switch. ### Claim 7 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the second physical module comprises a module that places the traffic in proper form for a pooling switch. ### Claim 8 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the traffic through the protected egress link and the alternate egress link have a synchronization difference smaller than 50 ms. ### Claim 9 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the traffic through the protected egress link and the alternate egress link behave in a manner to the user as if there is no synchronization difference between the two traffic flows. ### Claim 10 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the pooling switch enables multiple logical streams to be included in one physical interface. ### Claim 11 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein the pooling switch is a packet switch. ### Claim 12 (depends on 1) A method of protecting a protected egress link as in claim 1, wherein pooling switch is a time division multiplexing switch. ### Claim 13 A method of protecting a protected ingress link including: connecting traffic to a service module from a first physical module having a link layer framer that is connected via a link interface of the first physical module to the protected ingress link, wherein the link layer framer includes a queue for storing the traffic; and connecting the traffic through a second physical module that is connected via a link interface of the second physical module to an alternate ingress link through a pooling switch to the link interface of the first physical module, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through the link layer framer of the first physical module in the event that the traffic through the second physical module from the alternate ingress link is selected to be used. ### Claim 14 (depends on 13) A method of protecting a protected egress link as in claim 13, wherein the service module decides from information within an input traffic stream to the service module where to output the input traffic stream. ### Claim 15 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the link interface of the first physical module comprises an optical link interface module. ### Claim 16 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the link interface of the second physical module comprises an optical link interface module. ### Claim 17 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the link interface of the first physical module comprises an electrical link interface module. ### Claim 18 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the link interface of the second physical module comprises an electrical link interface module. ### Claim 19 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the first physical module contains a module that places the traffic in proper form for a pooling switch. ### Claim 20 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the second physical module contains a module that places the traffic in proper form for a pooling switch. ### Claim 21 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the traffic through the protected ingress link and the alternate ingress link have a synchronization difference smaller than 50 ms. ### Claim 22 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the traffic through the protected ingress link and the alternate ingress link behave in a manner to the user as if there is no synchronization difference between the two traffic flows. ### Claim 23 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the pooling switch enables multiple logical streams to be included in one physical interface. ### Claim 24 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein the pooling switch is a packet switch. ### Claim 25 (depends on 13) A method of protecting a protected ingress link as in claim 13, wherein pooling switch is a time division multiplexing switch. ### Claim 26 A method of protecting a protected egress link including: connecting traffic from a service module to a first pooling switch; connecting the first pooling switch to a first physical module having a link layer framer that is connected via a link interface of the first physical module to the protected egress link, wherein the link layer framer includes a queue for storing the traffic; and connecting the traffic input to the link interface of the first physical module through a second pooling switch to a second physical module that is connected via a link interface of the second physical module to an alternate egress link, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through the link layer framer of the first physical module. ### Claim 27 A method of protecting a protected ingress link including: connecting traffic to a service module from a first pooling switch; connecting the first pooling switch to a first physical module having a link layer framer that is connected via a link interface of the first physical module to the protected ingress link, wherein the link layer framer includes a queue for storing the traffic; and connecting the traffic through a second physical module that is connected via a link interface of the second physical module to an alternate ingress link through a second pooling switch to the link interface of the first physical module, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through the link layer framer of the first physical module in the event that the traffic through the second physical module from the alternate ingress link is selected to be used. ### Claim 28 A method of protecting a protected egress link including: connecting traffic from a service module to a first pooling switch; connecting the first pooling switch to a first physical module having a link layer framer, wherein the link layer framer includes a queue for storing the traffic; connecting the traffic through the first physical module through a second pooling switch to a second physical module that is connected via a link interface of the second physical module to a protected egress link, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed by the link layer framer of the first physical module; and connecting the traffic through the first physical module through the second pooling switch to a third physical module that is connected via a link interface of the third physical module to an alternate egress link, wherein the traffic in the third physical module is not processed through a link layer framer of the third physical module but is processed by the link layer framer of the first physical module. ### Claim 29 (depends on 28) A method of protecting a protected egress link as in claim 28, wherein the first physical module does not include a link interface module. ### Claim 30 (depends on 28) A method of protecting a protected egress link as in claim 28, wherein 1:N protection is provided. ### Claim 31 A method of protecting a protected ingress link including: connecting traffic to a service module from a first pooling switch; connecting the first pooling switch to a first physical module having a link layer framer, wherein the link layer framer includes a queue for storing the traffic; connecting the traffic through a second physical module that is connected via a link interface of the second physical module to a protected ingress link through a second pooling switch to the first physical module, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed by the link layer framer of the first physical module; and connecting the traffic through a third physical module that is connected via a link interface of the third physical module to an alternate ingress link through the second pooling switch to the first physical module, wherein the traffic in the third physical module is not processed through a link layer framer of the third physical module but is processed by the link layer framer of the first physical module. ### Claim 32 (depends on 31) A method of protecting a protected ingress link as in claim 31, wherein the first physical module does not include a link interface module. ### Claim 33 (depends on 31) A method of protecting a protected ingress link as in claim 31, wherein 1:N protection is provided. ### Claim 34 A system for protecting a protected egress link including: a service module; a first physical module, wherein the first physical module comprises a link layer framer that is connected via a link interface to the protected egress link, and wherein the link layer framer includes a queue for storing traffic, and wherein traffic is connected from the service module to the first physical module; a pooling switch; and a second physical module, wherein the second physical module is connected via a link interface of the second physical module to an alternate egress link, and wherein traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through a link layer framer of the first physical module, and wherein traffic input to the link interface of the first physical module through the polling switch to the second physical module. ### Claim 35 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the link interface of the first physical module comprises an optical link interface module. ### Claim 36 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the link interface of the second physical module comprises an optical link interface module. ### Claim 37 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the link interface of the first physical module comprises an electrical link interface module. ### Claim 38 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the link interface of the second physical module comprises an electrical link interface module. ### Claim 39 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the first physical module comprises a module that places the traffic in proper form for a pooling switch. ### Claim 40 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the second physical module comprises a module that places the traffic in proper form for a pooling switch. ### Claim 41 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the traffic through the protected egress link and the alternate egress link have a synchronization difference smaller than 50 ms. ### Claim 42 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the traffic through the protected egress link and the alternate egress link behave in a manner to the user as if there is no synchronization difference between the two traffic flows. ### Claim 43 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the pooling switch enables multiple logical streams to be included in one physical interface. ### Claim 44 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein the pooling switch is a packet switch. ### Claim 45 (depends on 34) A system for protecting a protected egress link as in claim 34, wherein pooling switch is a time division multiplexing switch. ### Claim 46 A system for protecting a protected ingress link including: a service module; a first physical module, wherein the first physical module comprises a link layer framer that is connected via a link interface to the protected ingress link, and wherein the link layer framer includes a queue for storing traffic, and wherein traffic is connected from the service module to the first physical module; a pooling switch; and a second physical module, wherein the second physical module is connected via a link interface of the second physical module to an alternate ingress link, and wherein traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through a link layer framer of the first physical module in the event that the traffic through the second physical module from the alternate ingress link is selected to be used, and wherein traffic is connected through the second physical module. ### Claim 47 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the service module decides from information within an input traffic stream to the service module where to output the input traffic stream. ### Claim 48 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the link interface of the first physical module comprises an optical link interface module. ### Claim 49 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the link interface of the second physical module comprises an optical link interface module. ### Claim 50 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the link interface of the first physical module comprises an electrical link interface module. ### Claim 51 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the link interface of the second physical module comprises an electrical link interface module. ### Claim 52 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the first physical module contains a module that places the traffic in proper form for a pooling switch. ### Claim 53 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the second physical module contains a module that places the traffic in proper form for a pooling switch. ### Claim 54 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the traffic through the protected ingress link and the alternate ingress link have a synchronization difference smaller than 50 ms. ### Claim 55 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the traffic through the protected ingress link and the alternate ingress link behave in a manner to the user as if there is no synchronization difference between the two traffic flows. ### Claim 56 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the pooling switch enables multiple logical streams to be included in one physical interface. ### Claim 57 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein the pooling switch is a packet switch. ### Claim 58 (depends on 46) A system for protecting a protected egress link as in claim 46, wherein pooling switch is a time division multiplexing switch. ### Claim 59 A system for protecting a protected egress link including: a service module; a first pooling switch, wherein traffic is connected from the service module to the first pooling switch; a first physical module, wherein the first pooling switch is connected to the first physical module having a link layer framer that is connected via a link interface of the first physical module to the protected egress link, wherein the link layer framer includes a queue for storing the traffic; and a second pooling switch; a second physical module, wherein the traffic input to the link interface of the first physical module is connected through the second pooling switch to the second physical module that is connected via a link interface of the second physical module to an alternate egress link, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through the link layer framer of the first physical module. ### Claim 60 A system for protecting a protected ingress link including: a service module; a first pooling switch, wherein traffic is connected to the service module from the first pooling switch; a first physical module, wherein the first pooling switch is connected to a first physical module having a link layer framer that is connected via a link interface of the first physical module to the protected ingress link, wherein the link layer framer includes a queue for storing the traffic; and a second physical module, wherein the traffic is connected through the second physical module that is connected via a link interface of the second physical module to an alternate ingress link through a second pooling switch to the link interface of the first physical module, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed through the link layer framer of the first physical module in the event that the traffic through the second physical module from the alternate ingress link is selected to be used. ### Claim 61 A system for protecting a protected egress link including: a service module; a first pooling switch, wherein traffic is connected from a service module to a first pooling switch; a first physical module, wherein the first pooling switch is connected to the first physical module having a link layer framer, wherein the link layer framer includes a queue for storing the traffic; a second pooling switch, wherein the traffic is connected through the first physical module through the second pooling switch to a second physical module that is connected via a link interface of the second physical module to a protected egress link, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed by the link layer framer of the first physical module; and a third physical module, wherein connecting the traffic is connected through the first physical module through the second pooling switch to the third physical module that is connected via a link interface of the third physical module to an alternate egress link, wherein the traffic in the third physical module is not processed through a link layer framer of the third physical module but is processed by the link layer framer of the first physical module. ### Claim 62 (depends on 61) A system for protecting a protected egress link as in claim 61, wherein the first physical module does not include a link interface module. ### Claim 63 (depends on 61) A system for protecting a protected egress link as in claim 61, wherein 1:N protection is provided. ### Claim 64 A system for protecting a protected ingress link including: a service module; a first pooling switch, wherein traffic is connected to the service module from the first pooling switch; a first physical module, wherein the first pooling switch is connected to the first physical module having a link layer framer, wherein the link layer framer includes a queue for storing the traffic; the second physical module, wherein the traffic is connected through the second physical module that is connected via a link interface of the second physical module to a protected ingress link through a second pooling switch to the first physical module, wherein the traffic in the second physical module is not processed through a link layer framer of the second physical module but is processed by the link layer framer of the first physical module; and a third physical module, wherein the traffic is connected through the third physical module that is connected via a link interface of the third physical module to an alternate ingress link through the second pooling switch to the first physical module, wherein the traffic in the third physical module is not processed through a link layer framer of the third physical module but is processed by the link layer framer of the first physical module. ### Claim 65 (depends on 64) A system for protecting a protected ingress link as in claim 64, wherein the first physical module does not include a link interface module. ### Claim 66 (depends on 64) A system for protecting a protected ingress link as in claim 64, wherein 1:N protection is provided.