Cloud applications need network data encryption to isolate from other tenants and protect their data from potential eavesdroppers in the network infrastructure. This paper presents SMT, a protocol design for emerging datacenter transport protocols, such as NDP and Homa, to integrate data encryption. SMT integrates TLS-based encryption with a message-based transport protocol that supports efficient Remote Procedure Calls (RPCs), a common workload in datacenters. This architecture enables the use of per-message record sequence number spaces in a secure session, while ensuring unique message identities to prevent replay attacks. It also enables the use of existing NIC offloads designed for TLS over TCP, while being a native transport protocol alongside TCP and UDP. We implement SMT in the Linux kernel by extending Homa/Linux and improve RPC throughput by up to 41 % and latency by up to 35 % in comparison to TLS/TCP.

Output-intensive scientific applications are highly sensitive to low storage throughput. While existing scientific application stacks are optimized for traditional High-Performance Computing (HPC) environments with high remote storage and network bandwidth, these assumptions often fail in modern settings like cloud deployment. This is because the existing scientific application I/O stack fails to leverage the available resources. At the same time, scientific applications exhibit special synchronization and data output requirements that are difficult to satisfy using traditional approaches such as block-level or filesystem-level caching. We introduce ParaLog, a distributed host-side logging approach designed to accelerate scientific applications transparently. ParaLog emphasizes deployability, enabling support for unmodified message passing interface (MPI) applications and implementations while preserving crash consistency semantics. We evaluate ParaLog across traditional HPC, cloud HPC, local clusters, and hybrid environments, demonstrating its capability to reduce end-to-end execution time by 13-26% for popular scientific applications in cloud settings.

While encryption has become ubiquitous across the Internet, there is growing concern that website fingerprinting and other traffic analysis attacks could undermine the confidentiality guarantees encryption is meant to provide. Over the past decade, these attacks have become increasingly effective, highlighting the urgent need to deploy traffic obfuscation countermeasures. Although defenses have already been proposed in the literature, they remain inefficient partly because they are implemented at the application-level, which limits their control over packet sequences. This paper advocates for integrating packet sequence obfuscation support directly into host network stacks, where the fine-grained packet operations that defenses require can be effectively enforced.

This paper presents SDP, a protocol design for emerging datacenter transports, such as NDP and Homa, to integrate data encryption. It supports NIC offloading designed for TLS over TCP, native protocol number alongside TCP and UDP, and message-based abstraction that enables low latency RPCs with fine-grained parallelism.

Cloud providers began to provide managed services to attract scientific applications, which have been traditionally executed on supercomputers. One example is AWS FSx for Lustre, a fully managed parallel file system (PFS) released in 2018. However, due to the nature of scientific applications, the frontend storage network bandwidth is left completely idle for the majority of its lifetime. Furthermore, the pricing model does not match the scalability requirement. We propose iFast, a novel host-side caching mechanism for scientific applications that improves storage bandwidth utilization and end-to-end application performance: by overlapping compute and data writeback through inexpensive local storage. iFast supports the Massage Passing Interface (MPI) library that is widely used by scientific applications and is implemented as a preloaded library. It requires no change to applications, the MPI library, or support from cloud operators. We demonstrate how iFast can accelerate the end-to-end time of a representative scientific application Neko, by 13–40%.

Networked storage applications cannot fully benefit from fast persistent memory (PM), because of data management overheads incurred to implement storage properties, such as integrity, consistency, search efficiency and flexibility. To address this problem, we explore a new approach that turns networking overheads into assets, repurposing the transport protocol and network stack features, some of which can be offloaded to the NIC hardware, for implementing the storage properties particularly for the PM devices.

In datacenters, workload throughput is often constrained by the attachment bandwidth of proxy servers, despite the much higher aggregate bandwidth of backend servers. We introduce a novel architecture that addresses this problem by combining programmable network switches with a controller that together act as a network "Prism" that can transparently redirect individual client transactions to different backend servers. Unlike traditional proxy approaches, with Prism, transaction payload data is exchanged directly between clients and backend servers, which eliminates the proxy bottleneck. Because the controller only handles transactional metadata, it should scale to much higher transaction rates than traditional proxies. An experimental evaluation with a prototype implementation demonstrates correctness of operation, improved bandwidth utilization and low packet transformation overheads even in software.

Network Function Virtualization has been touted as the silver bullet for tackling a number of operator problems, including vendor lock-in, fast deployment of new functionality, converged management, and lower expenditure since packet processing runs on inexpensive commodity servers. The reality, however, is that, in practice, it has proved hard to achieve the stable, predictable performance provided by hardware middleboxes, and so operators have essentially resorted to throwing money at the problem, deploying highly underutilized servers (e.g., one NF per CPU core) in order to guarantee high performance during peak periods and meet SLAs.

Video streaming dominates the Internet's overall traffic mix, with reports stating that it will constitute 90% of all consumer traffic by 2019. Most of this video is delivered by Content Delivery Networks (CDNs), and, while they optimize QoE metrics such as buffering ratio and start-up time, no single CDN provides optimal performance. In this paper we make the case for elastic CDNs, the ability to build virtual CDNs on-the-fly on top of shared, third-party infrastructure at a scale. To bring this idea closer to reality we begin by large-scale simulations to quantify the effects that elastic CDNs would have if deployed, and build and evaluate MiniCache, a specialized, minimalistic virtualized content cache that runs on the Xen hypervisor. MiniCache is able to serve content at rates of up to 32 Gb/s and handle up to 600K reqs/sec on a single CPU core, as well as boot in about 90 milliseconds on x86 and around 370 milliseconds on ARM32.

This paper argues that the lack of explicit support for non-volatile main memory (NVMM) in network stacks fundamentally limits application performance. NVMM devices have been integrated into general-purpose OSes by providing familiar file-based interfaces and efficient byte-granularity access by bypassing page caches. However, this powerful property cannot be fully utilized unless network stacks also support it and applications exploit such support. This requires a thoroughly new network stack design, including low-level buffer management and APIs. We propose such a new network stack architecture to support NVMM and demonstrate its advantages for efficient write-ahead logging, a popular technique to implement transactions.

Throughput-sensitive multimedia applications, such as on-demand video streaming and non-interactive live streaming require a high sending rate and a certain-level of smoothness. On the other hand, interactive streaming such as on-line conferencing requires a smooth sending rate. TFRC and TFWC support smoothness-sensitive multimedia applications, however, they cannot provide enough sending rate to throughput-sensitive multimedia applications. In this paper, we propose Tunable TFWC (TTFWC), an extension to TFWC to achieve various throughput behavior with regard to trade-off between smoothness and the sending rate based on application requirements. TTFWC supports throughput-sensitive multimedia applications in addition to smoothness-sensitive applications. Simulation results show that TTFWC with the value of tuning parameter 0.9 achieves approximately 10% higher throughput than the original TFWC without compromising TCP-Friendliness.

In sensing systems, data compression is a promised way to save energy because it reduces the rate of data transmission, but less attention has been paid to the underlying task scheduling algorithms. We present a Double Rate Bundle Scheduling algorithm (DRBS) that maximizes the sleep state period of the CPU to reduce energy consumption. Our prototype implementation in a Mote device improves energy efficiency up to 8% compared to existing algorithms.

We've known for a while that the Internet has ossified as a result of the race to optimize existing applications or enhance security. NATs, performance-enhancing-proxies,firewalls and traffic normalizers are only a few of the middleboxes that are deployed in the network and look beyond the IP header to do their job. IP itself can't be extended because "IP options are not an option". Is the same true for TCP?

Mobile nodes have limited computing resources, among which battery is one of the most important resources, since the lifetime of a node depends on the amount of battery and energy usage in the node. Application processes on mobile nodes include those are important for the users for certain duration of time, and those not. Therefore, exhausting whole battery for running non-important ones such as games, would be waste of energy. To maximize the user satisfactions with limited amount of energy, a sophisticated pacing mechanism is required for energy usage. We propose a process lifetime reservation system, called “pSurvive.” It enables users to reserve energy for running specific processes for a certain duration of time. Users are allowed to run any applications until the total energy consumption reaches the “deadline” to run the reserved processes. pSurvive enables this with the following three novel mechanisms. First, P-Monitor monitors running processes and devices (e.g. NIC, LCD, etc.) in a node for their energy consumption. Second, P-Analyzer estimates future energy consumption based on the energy usage information given by P-Monitor. Third, P-Reserver accepts energy reservation requests from users, and pace the energy consumption by shedding unnecessary tasks. This paper first discusses requirements for energy reservation on mobile nodes. It then reports the design and the implementation of pSurvive for Android mobile nodes, and shows that pSurvive achieves process lifetime reservation based on the fine-grained energy monitoring.

Migration between different wireless access networks often involves disconnected period, which is caused by passing an area of bad wireless coverage and potential overhead to switch the network on the network interface to connect to. The disconnected period can cause extra transmission delay due to the timer-driven retransmission behavior in the transport protocols, such as TCP and SCTP. We propose a new retransmission scheme to achieve better migration performance in SCTP, which is a newer connection-oriented and reliable transport protocol that is becoming popular. Our scheme minimizes the extra transmission delay by leveraging address reconfiguration operation in SCTP without involving other layers. It decreases the delay more than 5 seconds compared to the original SCTP when migration involves approximately ten-second disconnected period. The implementation of our scheme is already imported in FreeBSD.

PR-SCTP provides a timeliness transport service. When the lifetime of the data specified by the application expires, the sender PR-SCTP gives up retransmitting the data, and transmits a Forward TSN chunk to make the receiver advance the Cumulative ACK point. However, on the mobile communication, connectivity of the nodes is intermittent. PRSCTP does not work properly in this case, thereby the timeliness transmission is impaired. In order to address this issue, we propose a new algorithm that transmits a Forward TSN triggered by readdressing events in SCTP associations. Our scheme allows PR-SCTP to restart transmission of data with lifetime smoothly regardless of duration of the connectivity disruption.

Many handover techniques in the Internet have been introduced with the development of mobile computing technologies. Although many proposed handover schemes utilize multiple interfaces, having multiple interfaces can increase power consumption, device installation space and hardware costs of mobile devices. Therefore, we have been studying handover schemes for mobile nodes with a single wireless network interface. To achieve seamless and efficient handover, we focus on stream control transmission protocol (SCTP) which offers message-oriented, reliable and connection-oriented delivery transport service. Unlike other transport protocols such as TCP, SCTP can provide an end-to-end handover mechanism with a multi-homing feature. However, the handover mechanism in the current SCTP causes large handover delay especially when a mobile node has only one single wireless network interface. In this paper, we have investigated the current issues in the SCTP handover mechanism and propose a new handover scheme based on SCTP, which identifies a communication path as a pair of source and destination address. We also propose new data retransmission feature for smooth handover.