Patent ID: 8468225

Claim:
A system for roaming Transmission Control Protocol (TCP) connections when physical networks are changed, comprising: (a) a first host device comprising a virtual Network Interface Card (NIC) having a unique Internet Protocol (IP) address; (b) a second host device between which said first host device a TCP connection is able to be established using address endpoints of the virtual IP; and (c) a physical-to-virtual gateway device with a corresponding virtual NIC having a unique IP address, wherein the virtual NIC of said gateway device is operable to set a sliding window size of said first host device to 0 during network transition periods of said first host device, causing outgoing TCP data to be effectively paused, and to set said sliding window to its initial size when a new physical network connection for said first host device is established, wherein said gateway device is operable to notify at least said second host device that said TCP connection has not been terminated during said network transition periods and that the outgoing TCP data is transmittable after establishing a new physical network connection for said first host device.