Method, system, and device for forwarding data frames

Abstract

The present disclosure discloses a method, system, and device for forwarding data frames, and relates to the communication field. The method includes the following steps: An upstream near-end device in a faulty part of a working tunnel activates a segmental protection tunnel after receiving a data frame when a part of the working tunnel fails, where the start node of the segmental protection tunnel is the upstream near-end device and the end node of the segmental protection tunnel is a downstream near-end device in the faulty part; the upstream near-end device forwards the data frame to the downstream near-end device through the segmental protection tunnel; and the data frame at the downstream near-end device is forwarded to the destination device through the faultless part of the working tunnel. The present disclosure provides segmental protection for the PBB TE tunnel.

1 . A method for forwarding data frames, comprising:
 by an upstream near-end device in a faulty part of a working tunnel, activating a segmental protection tunnel after receiving a data frame when a part of the working tunnel fails, wherein a start node of the segmental protection tunnel is the upstream near-end device and an end node of the segmental protection tunnel is a downstream near-end device in the faulty part;   forwarding the data frame to the downstream near-end device through the segmental protection tunnel; and   forwarding the data frame from the downstream near-end device to a destination device through a faultless part of the working tunnel.   
     
     
         2 . The method according to  claim 1 , wherein the step of activating the segmental protection tunnel comprises:
 by the upstream near-end device, enabling its own segmental protection forwarding table, and disabling a faultless forwarding table; and   obtaining an identifier of the working tunnel from the data frame, searching the segmental protection forwarding table for an egress identifier corresponding to the identifier of the working tunnel, and activating the segmental protection tunnel corresponding to the egress identifier.   
     
     
         3 . The method according to  claim 1 , wherein:
 the step of activating the segmental protection tunnel comprises: by the upstream near-end device, searching for an identifier of the corresponding segmental protection tunnel according to a destination address carried in the data frame, modifying a working tunnel identifier carried in the data frame to the identifier of the segmental protection tunnel, searching the forwarding table for the corresponding segmental protection tunnel according to the destination address and the identifier of the segmental protection tunnel, and activating the segmental protection tunnel;   the step of forwarding the data frame to the downstream near-end device through the segmental protection tunnel comprises: forwarding the modified data frame to the downstream near-end device through the segmental protection tunnel; and   the step of forwarding the data frame from the downstream near-end device to the destination device through the faultless part of the working tunnel comprises: by the downstream near-end device, modifying the segmental protection tunnel identifier in the data frame to the identifier of the working tunnel after receiving the data frame from the segmental protection tunnel, and forwarding the modified data frame to the destination device through the faultless part of the working tunnel.   
     
     
         4 . The method according to  claim 1 , wherein:
 the step of activating the segmental protection tunnel comprises: by the upstream near-end device, encapsulating the data frame, wherein the encapsulated data frame carries address information for bypassing the faulty part; searching for the segmental protection tunnel according to the address information for bypassing the faulty part, and activating the found segmental protection tunnel;   the step of forwarding the data frame to the downstream near-end device through the segmental protection tunnel comprises: forwarding the encapsulated data frame to the downstream near-end device through the found segmental protection tunnel; and   the step of forwarding the data frame from the downstream near-end device to the destination device through the faultless part of the working tunnel comprises: by the downstream near-end device, receiving the data frame from the segmental protection tunnel, decapsulating the data frame, removing the address information for bypassing the faulty part carried in the data frame, and forwarding the decapsulated data frame to the destination device through the faultless part of the working tunnel.   
     
     
         5 . The method according to  claim 1 , wherein after the data frame is forwarded from the downstream near-end device to the destination device through the faultless part of the working tunnel, the method further comprises:
 using the faulty part as a part of the working tunnel if the faulty part recovers to noiinal in a preset time; and   combining the segmental protection tunnel with the faultless part of the working tunnel into a new working tunnel if the faulty part does not recover to normal in the preset time.   
     
     
         6 . The method according to  claim 5 , wherein:
 the step of using the faulty part as a part of the working tunnel comprises: by the upstream near-end device, enabling the faultless forwarding table, disabling the segmental protection forwarding table, and forwarding the data frame through an egress corresponding to the egress identifier in the faultless forwarding table; and   the step of combining the segmental protection tunnel with the faultless part of the working tunnel into the new working tunnel comprises: by the upstream near-end device, enabling the faultless forwarding table, disabling the segmental protection forwarding table, modifying the egress identifier corresponding to the working tunnel identifier in the faultless forwarding table to the corresponding egress identifier in the segmental protection forwarding table, and forwarding the data frame through the egress corresponding to the egress identifier in the modified faultless forwarding table.   
     
     
         7 . The method according to  claim 5 , wherein:
 the step of using the faulty part as a part of the working tunnel comprises: forwarding, by the upstream near-end device, the received data frame through the faulty part recovered to normal; and   the step of combining the segmental protection tunnel with the faultless part of the working tunnel into the new working tunnel comprises: modifying, by the upstream near-end device, the segmental protection tunnel identifier in its own forwarding table to the identifier of the working tunnel; by the downstream near-end device, modifying the working tunnel identifier in its own forwarding table to the identifier of the segmental protection tunnel, and forwarding the data frame to the destination device.   
     
     
         8 . The method according to  claim 5 , wherein:
 the step of using the faulty part as a part of the working tunnel comprises: forwarding, by the upstream near-end device, the received data frame through the faulty part recovered to normal; and   the step of combining the segmental protection tunnel with the faultless part of the working tunnel into the new working tunnel comprises: by the upstream near-end device, adding an entry for reaching the destination device to its own forwarding table, wherein an egress of the entry is an egress connected to the segmental protection tunnel; deleting an old entry for reaching the destination device in the forwarding table; and forwarding the data frame to the destination device.   
     
     
         9 . The method according to  claim 1 , wherein:
 the segmental protection tunnel is implemented by means of static configuration performed by a Network Management System (NMS) or by means of static configuration performed through a path calculated out by a Path Computation Element (PCE).   
     
     
         10 . The method according to  claim 1 , wherein:
 the segmental protection tunnel is implemented by means of signaling calculation performed through a Generalized Multi-Protocol Label Switching (GMPLS) protocol, or by means of signaling calculation performed through a Fast Re-Routing (FRR) technology.   
     
     
         11 . A system for forwarding data frames, comprising:
 an upstream near-end device, which is located at an upstream near end of a fault when a working tunnel fails, and is configured to activate a segmental protection tunnel and send a data frame to the segmental protection tunnel, wherein the upstream near-end device is a start node of the segmental protection tunnel; and   a downstream near-end device, which is located at a downstream near end of the fault when the working tunnel fails, and is configured to receive the data frame forwarded by the segmental protection tunnel and forward the data frame to a destination device through a faultless part of the working tunnel, wherein the downstream near-end device is an end node of the segmental protection tunnel.   
     
     
         12 . The system according to  claim 11 , wherein the upstream near-end device comprises:
 a receiving module, configured to receive the data frame;   a switching module, configured to enable its own segmental protection forwarding table and disable a faultless forwarding table when a part of the working tunnel fails;   an obtaining module, configured to obtain a working tunnel identifier in the data frame received by the receiving module;   a searching and activating module, configured to: search the segmental protection forwarding table enabled by the switching module for an egress identifier corresponding to the working tunnel identifier according to the working tunnel identifier obtained by the obtaining module, and activate the segmental protection tunnel corresponding to the egress identifier; and   a forwarding module, configured to forward the data frame through the segmental protection tunnel activated by the searching and activating module.   
     
     
         13 . The system according to  claim 11 , wherein:
 the upstream near-end device comprises:
 a receiving module, configured to receive the data frame; 
 a modifying module, configured to: obtain an identifier of the segmental protection tunnel corresponding to a destination address carried in the data frame received by the receiving module when a part of the working tunnel fails, and modify a working tunnel identifier in the data frame to the identifier of the segmental protection tunnel; 
 a searching and activating module, configured to: search a forwarding table for the corresponding segmental protection tunnel according to the destination address in the data frame modified by the modifying module and the identifier of the segmental protection tunnel, and activate the segmental protection tunnel; and 
 a forwarding module, configured to forward the data frame modified by the modifying module through the segmental protection tunnel activated by the searching and activating module; 
   the downstream near-end device comprises:
 a receiving module, configured to receive the data frame; 
 a modifying module, configured to modify the identifier of the segmental protection tunnel in the data frame received by the receiving module of the downstream near-end device to the working tunnel identifier; and 
 a forwarding module, configured to forward the data frame modified by the modifying module of the downstream near-end device to the destination device through the faultless part of the working tunnel. 
   
     
     
         14 . The system according to claim, wherein:
 the upstream near-end device comprises:
 a receiving module, configured to receive the data frame; 
 an encapsulating modulo, configured to encapsulate the data frame received by the receiving module when a part of the working tunnel fails, wherein the encapsulated data frame carries address information for bypassing the faulty part of the working tunnel; 
 a searching and activating modulo, configured to: search for the segmental protection tunnel according to the address information for bypassing the faulty part in the data frame encapsulated by the encapsulating module, and activate the found segmental protection tunnel; and 
 a forwarding module, configured to forward the data frame encapsulated by the encapsulating module through the segmental protection tunnel activated by the searching and activating module. 
   the downstream near-end device comprises:
 a receiving module, configured to receive the data frame; 
 a decapsulating module, configured to: decapsulate the data frame received by the receiving module of the downstream near-end device, and remove the address information for bypassing the faulty part in the data frame; and 
 a forwarding module, configured to forward the data frame decapsulated by the decapsulating modulo to the destination device through the faultless part of the working tunnel. 
   
     
     
         15 . The system according to  claim 11 , comprising:
 an intermediate device, which is located in the segmental protection tunnel when the working tunnel fails, and is configured to receive the data frame sent by the upstream near-end device and forward the data frame to the downstream near-end device.   
     
     
         16 . An upstream near-end device, comprising:
 a receiving module, configured to receive a data frame;   an activating module, configured to activate a segmental protection tunnel when a working tunnel fails; and   a forwarding module, configured to forward the data frame received by the receiving module ( 501 ) to the segmental protection tunnel activated by the activating module.   
     
     
         17 . The upstream near-end device according to  claim 16 , wherein the activating module comprises:
 a switching unit, configured to enable its own segmental protection forwarding table and disable a faultless forwarding table when a part of the working tunnel fails;   an obtaining unit, configured to obtain a working tunnel identifier in the data frame received by the receiving module;   a searching and activating unit, configured to: search the segmental protection forwarding table enabled by the switching unit for an egress identifier corresponding to the working tunnel identifier according to the working tunnel identifier obtained by the obtaining unit, and activate the segmental protection tunnel corresponding to the egress identifier.   
     
     
         18 . The upstream near-end device according to  claim 17 , wherein the forwarding module of the device further comprises:
 a judging unit, configured to judge whether the faulty part recovers to normal in a preset time;   a first forwarding table switching unit, configured to enable its own faultless forwarding table and disable the segmental protection forwarding table when the judging unit-determines that the faulty part recovers to normal; and   a second forwarding table switching unit, configured to: enable the faultless forwarding table and disable the segmental protection forwarding table when the judging unit-determines that the faulty part does not recover to normal, and replace the egress identifier corresponding to the working tunnel identifier in the enabled faultless forwarding table with the corresponding egress identifier in the segmental protection forwarding table.   
     
     
         19 . The upstream near-end device according to  claim 16 , wherein the activating module comprises:
 a modifying unit, configured to: obtain an identifier of the segmental protection tunnel corresponding to a destination address carried in the data frame received by the receiving module when a part of the working tunnel fails, and modify a working tunnel identifier in the data frame to the identifier of the segmental protection tunnel; and   a searching and activating unit, configured to: search a forwarding table for the corresponding segmental protection tunnel according to the destination address in the data frame modified by the modifying unit and the identifier of the segmental protection tunnel, and activate the segmental protection tunnel.   
     
     
         20 . The upstream near-end device according to  claim 19 , wherein the forwarding module of the device further comprises:
 a judging unit, configured to judge whether the faulty part recovers to normal in a preset time;   a first forwarding unit, configured to forward the data frame received by the receiving module through the faulty part recovered to normal when the judging unit determines that the faulty part recovers to normal; and   a second forwarding unit, configured to: modify the identifier of the segmental protection tunnel in the forwarding table to the working tunnel identifier when the judging unit-determines that the faulty part does not recover to normal, and forward the data frame received by the receiving module ( 501 ) to a destination device.   
     
     
         21 . The upstream near-end device according to  claim 16 , wherein the activating module comprises:
 an encapsulating unit, configured to encapsulate the data frame received by the receiving module when a part of the working tunnel fails, wherein the encapsulated data frame carries address information for bypassing the faulty part; and   a searching and activating unit, configured to: search for the segmental protection tunnel according to the address information for bypassing the faulty part in the data frame encapsulated by the encapsulating unit, and activate the found segmental protection tunnel.   
     
     
         22 . The upstream near-end device according to  claim 21 , wherein the forwarding module of the device comprises:
 a judging unit, configured to judge whether the faulty part recovers to normal in a preset time;   a first forwarding unit, configured to forward the data frame received by the receiving module through the faulty part recovered to normal when the judging unit determines that the faulty part recovers to normal; and   a second forwarding unit, configured to: add an entry for reaching a destination device to its own forwarding table when the judging unit determines that the faulty part does not recover to normal, wherein an egress of the entry is connected to the segmental protection tunnel; delete an old entry for reaching the destination device in the forwarding table; and forward the data frame received by the receiving module to the destination device.   
     
     
         23 . A downstream near-end device, comprising:
 a receiving module, configured to receive a data frame;   a modifying module, configured to modify the data frame received by the receiving module when a working tunnel fails; and   a forwarding module, configured to forward the data frame modified by the modifying module to a destination device through a faultless part of the working tunnel.   
     
     
         24 . The downstream near-end device of  claim 23 , wherein the modifying module is:
 an identifier modifying unit, configured to modify an identifier of a segmental protection tunnel in the data frame received by the receiving module to a working tunnel identifier when the working tunnel fails.   
     
     
         25 . The downstream near-end device according to  claim 24 , further comprising:
 an updating module, configured to: modify the working tunnel identifier in a forwarding table to the identifier of the segmental protection tunnel when a faulty part does not recover to normal in a preset time, and forward the data frame to the destination device.   
     
     
         26 . The downstream near-end device according to  claim 23 , wherein the modifying module is:
 a decapsulating unit, configured to: decapsulate the data frame received by the receiving module when a part of the working tunnel fails, and remove address information for bypassing the faulty part the data frame.