Synchronization between active TCP application and standby TCP application

摘要

Embodiments of the invention include a method for maintaining an active-standby relationship between an active control card and a standby control card in a network element. The network element receives a data from a remote peer at the active control card. The network element communicates data from the active TCP module to an active application module in the active control card. The network element communicates synchronization data from the active application module to a standby application module on the standby control card. The network element communicates a single application synchronization acknowledgement from the standby application module to the active APP module. The network element communicates an application acknowledgment packet from the active application module to the active TCP module responsive to receiving the application synchronization acknowledgment. The network element then communicates an acknowledgement to the remote peer responsive to the application acknowledgement.

主权项

1. A method performed in a network element for maintaining an active-standby relationship between an active control card and a standby control card, the method comprising the steps of:
receiving a data packet from a remote network element at an active transport control protocol (“TCP”) module in the active control card; communicating at least a portion of the data packet from the active TCP module to an active application (“APP”) module in the active control card; communicating an APP synchronization (“SYNC”) message from the active APP module to a standby APP module on the standby control card responsive to receiving the at least a portion of the data packet; receiving a single APP SYNC acknowledgement (“ACK”) message from the standby APP module at the active APP module, indicating successful delivery of the APP SYNC message; communicating an APP ACK message from the active APP module to the active TCP module responsive to receiving the APP SYNC ACK message; and communicating a data ACK message from the active TCP module to the remote network element responsive to receiving the APP ACK message, wherein the data ACK message indicates successful delivery of the data packet, wherein the active APP module comprises an active border gateway protocol (“BGP”) process and the standby APP module comprises a standby BGP APP, wherein the data packet comprises a BGP update message and the APP SYNC message comprises data used be the standby BGP APP to synchronize state information with the active BGP APP, and wherein the communicating the APP SYNC message from the active BGP APP to the standby BGP APP comprising:
reading, at the active BGP APP, one or more BGP route updates contained within the BGP update message;discarding, at the active BGP APP, one or more BGP route updates based on one or more policies from a local policy information base;determining a set of one or more BGP state changes based on an active BGP APP state, the one or more read BGP route updates, and the one or more discarded BGP route updates; andgenerating the APP SYNC message to comprise the set of BGP state changes.