Protocols such as TCP and congestion control mechanisms like TFRC (TCP-friendly rate control) suffer in a hybrid wired-cum-wireless scenario where losses can occur for reasons other than congestion, viz., due to bit errors in the wireless link. The existing solutions to address the problem either misclassify the losses, violate end-to-end semantics, do not coexist with IPSec or are TCP-specific. We have previously proposed an innovative mechanism, secure performance enhancing proxy (SPEP), which preserves end-to-end semantics, ensures end-to-end security and enhances performance. We show that the decoupling of loss differentiation from the loss recovery mechanism enables SPEP to serve as a generic loss differentiation mechanism at the network layer. We show by means of test bed experiments that SPEP works in conjunction with any transport layer and protocols such as UDP with TFRC.
['Venkatesh Obanaik', 'Zhao Hang', 'Akkihebbal L. Ananda']
Decoupling loss differentiation and loss recovery to ensure security and performance