Patent ID: 7778256

Claim:
A method for implementing virtual circuit status consistency, comprising: receiving, by a second provider edge router, a first extended network layer reachability information (NLRI) message from a first provider edge router, wherein the NLRI includes a circuit status vector (CSV) property; when a first value included in the CSV property represents that a station of the first provider edge router is available, establishing, by the second provider edge router, a virtual circuit from the second provider edge router to the first provider edge router; determining, by the second provider edge router, a status of a virtual circuit from the first provider edge router to the second provider edge router, according to a second extended NLRI message received from the first provider edge router, wherein a second value included in the CSV property represents the status of the virtual circuit from the first provider edge router to the second provider edge router; and updating, by the second provider edge router, a status of the virtual circuit from the second provider edge router to the first provider edge router, so as to make the status of the virtual circuit from the second provider edge router to the first provider edge router consistent with that of the virtual circuit from the first provider edge router to the second provider edge router.