Damon Wischik

Learn More
Multipath TCP, as proposed by the IETF working group mptcp, allows a single data stream to be split across multiple paths. This has obvious benefits for reliability, and it can also lead to more efficient use of networked resources. We describe the design of a multipath congestion control algorithm, we implement it in Linux, and we evaluate it for(More)
The latest large-scale data centers offer higher aggregate bandwidth and robustness by creating multiple paths in the core of the net- work. To utilize this bandwidth requires different flows take different paths, which poses a challenge. In short, a single-path transport seems ill-suited to such networks. We propose using Multipath TCP as a replacement(More)
In large multiplexers with many TCP flows, the aggregate traffic flow behaves predictably; this is a basis for the fluid model of Misra, Gong and Towsley V. Misra et al., (2000) and for a growing literature on fluid models of congestion control. In this paper we argue that different fluid models arise from different buffer-sizing regimes. We consider the(More)
Multipath transport protocols have the potential to greatly improve the performance and resilience of Internet traffic flows. The basic idea is that if flows are able to simultaneously use more than one path through the network, then they will be more resilient to problems on particular paths (e.g. transient problems on a radio interface), and they will be(More)
Since the ARPAnet, network designers have built localized mechanisms for statistical multiplexing, load balancing, and failure resilience, often without understanding the broader implications. These mechanisms are all types of resource pooling whichmeans making a collection of resources behave like a single pooled resource. We believe that the natural(More)
Consider a switch which queues traac from many independent input ows. We show that in the large deviations limiting regime in which the number of inputs increases and the service rate and buuer size are increased in proportion, the statistical characteristics of a ow are essentially unchanged by passage through the switch. This signiicantly simpliies the(More)
In this article we describe recent work on buffer sizing for core Internet routers. This work suggests that the widely-used rule of thumb leads to buffers which are much larger than they need to be. For example, the buffer in a backbone router could be reduced from 1,000,000 packets to 10,000 without loss in performance. It could be reduced even further,(More)
The input-queued switch architecture is widely used in Internet routers, due to its ability to run at very high line speeds. A central problem in designing an input-queued switch is choosing the scheduling algorithm, i.e. deciding which packets to transfer from ingress ports to egress ports in a given timeslot. Important metrics for evaluating a scheduling(More)
There are moves in the Internet architecture community to add multipath capabilities to TCP, so that end-systems will be able to shift their traffic away from congested parts of the network. We study two problems relating to the design of multipath TCP. (i) We investigate stochastic packet-level behaviour of some proposed multipath congestion control(More)
We consider a queueing network in which there are constraints on which queues may be served simultaneously; such networks may be used to model input-queued switches and wireless networks. The scheduling policy for such a network specifies which queues to serve at any point in time. We consider a family of scheduling policies, related to the maximum-weight(More)