Patent ID: 8379638
Filing Date: 2013-02-19
Classification: H04L

Abstract:
1. A method for providing security functions to data packets at the data link layer of the Open Systems Interconnection Reference Model, the method comprising: receiving, at the data link layer, a data packet having an Ethernet frame having an original header and original payload; encrypting, at the data link layer, the original payload to provide an encrypted payload that is longer than the original payload; fragmenting, at the data link layer, the encrypted payload into first and second output Ethernet frames if the size of the encrypted payload would result in the first output Ethernet frame exceeding a Path Maximum Transmission Unit limit for the data link layer; determining an encapsulation header for each of the first and second output Ethernet frames, the encapsulation header including a non-encrypted fragmentation field containing information to enable, at the data link layer, reconstruction of the encrypted payload from the first and second output Ethernet frames; constructing, at the data link layer, the first and second output Ethernet frames from the original header, the encapsulation header, and the encrypted payload, to provide security functions to the data packet at the data link layer.