Patent ID: 8407548

Claim:
A method comprising: at a data receiving unit, receiving a first frame via a first channel; at the data receiving unit, determining a first sequence number of the first frame; at the data receiving unit, determining that a second frame associated with a second sequence number has not been received within a sliding window of a sliding window protocol, wherein the second sequence number is less than the first sequence number; at the data receiving unit, responsive to determining that the second frame has not been received, establishing a logical tunnel channel with a data sending unit; transmitting, from the data receiving unit to the data sending unit via the logical tunnel channel, a first request for retransmission of the second frame, the first request comprising an indication of a number of consecutively missed frames, wherein use of the logical tunnel channel allows a transmit window to advance without detecting an acknowledgement of receipt of the second frame; at the data receiving unit, starting a first timer; at the data receiving unit, detecting an expiration of the first timer before the second frame is received; and at the data receiving unit, responsive to detecting the expiration of the first timer before the second frame is received, transmitting, to the data sending unit via the logical tunnel channel, a second request for retransmission of the second frame, the second request comprising an indication of a number of consecutively missed frames.