Abstract: A system and method establishes bidirectional contact through firewall devices. A method includes establishing a first connection between a first device and a second device and storing a connection record on the second device. When the second device receives a request to connect with the first device, it identifies and searches for the connection record corresponding to the first device. When the second device finds the connection, the second device sends a request to establish a second connection from the second device to the first device. Upon receiving the request to establish a second connection, the first device verifies the request to establish the second connection and the lifetime of the first connection. Upon verification, the first device establishes the second connection between the first computing device and the second device.

Abstract: Systems and methods for replicating data from a production server to a backup server include identifying one or more data blocks of a file that were modified after a first time instant and before a second time instant. The file may be associated with a protected directory of the production server. An representative data block (e.g., including a hash value) for at least one of the identified data blocks may be computed using a cryptography algorithm, e.g., MD5 or SHA-1. The computed cryptographic data block representing the identified data block may then be sent for replication to the backup server. An operation performed between the first time instant and the second time instant on one or more files of the protected directory may be recorded, and sent to the backup server.

Abstract: Systems and methods for replicating data from a production server to a backup server include identifying one or more data blocks of a file that were modified after a first time instant and before a second time instant. The file may be associated with a protected directory of the production server. An representative data block (e.g., including a hash value) for at least one of the identified data blocks may be computed using a cryptography algorithm, e.g., MD5 or SHA-1. The computed cryptographic data block representing the identified data block may then be sent for replication to the backup server. An operation performed between the first time instant and the second time instant on one or more files of the protected directory may be recorded, and sent to the backup server.