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In both TCP and SCTP, selectively acked (SACKed) out-of-order data is implicitly renegable; that is, the receiver can later discard SACKed data. The possibility of reneging forces the transport sender to maintain copies of SACKed data in the send buffer until they are cumulatively acked. In this paper, we investigate the situation where all out-of-order(More)
We investigate how path failure influences Concurrent Multipath Transfer (CMT) using SCTP multihoming. We show that CMT suffers from significant ‘‘receive buffer blocking” which degrades performance during both permanent and short-term failure. To improve performance, we introduce a new ‘‘Potentially-Failed” (PF) destination state, and revise CMT’s failure(More)
We first explain problems with the default scheduler used by the Linux kernel MPTCP implementation. Then we propose the design of a new scheduler. Preliminary empirical results show that our proposed scheduler improves the throughput in MPTCP by alleviating the problems caused by the default scheduler.
Previously, we identified the failure-induced receive buffer (rbuf) blocking problem in Concurrent Multipath Transfer using SCTP multihoming (CMT), and proposed CMT with a Potentially-failed destination state (CMTPF) to alleviate rbuf blocking. In this paper, we complete our evaluation of CMT vs. CMT-PF. Using ns-2 simulations we show that CMT-PF performs(More)
Preliminary work introduced Non-Renegable Selective Acknowledgments (NR-SACKs) and showed they (i) better utilize a data sender’s memory in both SCTP and CMT, and (ii) improve throughput in CMT. In this paper, we provide the latest specification of NR-SACKs, and extend the investigation of throughput improvements that NR-SACKs can provide. Using ns-2(More)
Data reneging occurs when a data receiver first SACKs data, and later discards that data from its receiver buffer prior to delivering it to the receiving application or socket buffer. Today’s reliable transport protocols such as TCP and SCTP are designed to tolerate data reneging. We argue that this design assumption is wrong, in part based on a hypothesis(More)
While analyzing CAIDA Internet traces of TCP traffic to detect instances of data reneging, we frequently observed seven misbehaviors in the generation of SACKs. These misbehaviors could result in a data sender mistakenly thinking data reneging occurred. With one misbehavior, the worst case could result in a data sender receiving a SACK for data that was(More)
Reneging occurs when a transport layer data receiver first selectively acks data, and later discards that data from its receiver buffer prior to delivery to the receiving application or socket buffer. Reliable transport protocols such as TCP (Transmission Control Protocol) and SCTP (Stream Control Transmission Protocol) are designed to tolerate reneging. We(More)
Previously, we identified the failure-induced receive buffer (rbuf) blocking problem in Concurrent Multipath Transfer using SCTP multihoming (CMT), and proposed CMT with a Potentially-failed destination state (CMT-PF) to alleviate rbuf blocking. In this paper we complete our evaluation of CMT vs. CMT-PF. Using NS-2 simulations we first show that CMT-PF(More)