IEEE Journal on Selected Areas in Communications

The popularization of cloud computing has raised concerns over the energy consumption that takes place in data centers. In addition to the energy consumed by servers, the energy consumed by large numbers of network devices emerges as a significant problem. Existing work on energy-efficient data center networking primarily focuses on traffic engineering, which is usually adapted from traditional ne... View full abstract»

We propose an analytical model able to accurately estimate both power consumption and network performance indexes of Energy Efficient Ethernet (EEE) links working at the three available speeds under various traffic load patterns and packet size distributions. The model is sufficiently flexible and accurate to consider different traffic parameters; among others, the packet size distribution, the av... View full abstract»

Cloud Computing (CC) services are rapidly catching on as an alternative to conventional office-based computing. As cloud computing adoption increases, the energy consumption of the network and of the computing resources that underpin the cloud is growing and causing the emission of enormous quantities of CO2. Research is now focusing on novel "low-carbon" cloud-computing solutions. Rene... View full abstract»

In today's data centers, the round trip propagation delay is quite small. Therefore, switch buffer sizes are much larger than the Bandwidth Delay Product (BDP). Based on this observation, in this paper we introduce a new transport protocol which provides bandwidth Sharing by Allocating switch Buffer (SAB) for data centers. SAB sets the congestion windows for flows based on the buffer size of the s... View full abstract»

TCP has been widely adopted in current data centers to ensure reliable data delivery. However, recently TCP Incast was found to occur in many-to-one communications with barrier-synchronized requirement, where the TCP goodput drops dramatically. Previous solutions to TCP Incast either require updating the OS/hardware to support fine-grained timers, or smartly control utilization of the switch buffe... View full abstract»

Many applications (e.g., cluster based storage and MapReduce) in modern data centers require a high fan-in, many-to-one type of data communication (known as TCP incast), which could cause severe incast congestion in switches and result in TCP goodput collapse, substantially degrading the application performance. The root cause of such a collapse is the long idle period of the Retransmission Timeou... View full abstract»

Datacenter-based Cloud computing has induced new disruptive trends in networking, key among which is network virtualization. Software-Defined Networking overlays aim to improve the efficiency of the next generation multitenant datacenters. While early overlay prototypes are already available, they focus mainly on core functionality, with little being known yet about their impact on the system leve... View full abstract»

With the growing popularity of big-data applications, Data Center Networks (DCN) increasingly carry larger and longer traffic flows. As a result of this increased flow granularity, static routing cannot efficiently load-balance traffic, resulting in an increased network contention and a reduced throughput. Unfortunately, while adaptive routing can solve this load-balancing problem, DCN designers r... View full abstract»

Multicast benefits numerous data center applications that require group communication by eliminating sending unnecessary duplicated packets in the network, thus significantly reduces network traffic and improves application throughput. Meanwhile, most data center networks (DCNs) today adopt a multi-rooted tree structure called fat-tree, which utilizes rich path multiplicity to deliver high bisecti... View full abstract»

This paper introduces a new scalable, efficient and stateless source routing scheme to ensure that unified unicast and multicast packets can be delivered in the Data Center Networks (DCNs). This scheme, called Code-Oriented eXplicit multicast (COXcast), is based on unicast and eXplicit multicast (Xcast). It constructs the unicast path and multicast tree by encoding the corresponding output port bi... View full abstract»

The key challenge to a datacenter network is its scalability to handle many customers and their applications. In a datacenter network, packet classification plays an important role in supporting various network services. Previous algorithms store classification rules with the same length combinations in a hash table to simplify the search procedure. The search performance of hash-based algorithms ... View full abstract»

With the rise of datacenter virtualization, the number of entries in the forwarding tables of datacenter switches is expected to scale from several thousands to several millions. Unfortunately, such forwarding table sizes would not fit on-chip memory using current implementations. In this paper, we investigate the compressibility of forwarding tables. We first introduce a novel forwarding table ar... View full abstract»