The DNS is a key component of the Internet. Originally designed to facilitate the resolution of host names to IP addresses, its scope has continuously expanded over the years, today covering use cases such as load balancing or service discovery. While DNS was initially conceived as a rather static directory service in which resource records (RR) only change rarely, we have seen a number of use cases over the years where a DNS flavor that isn't purely based upon requesting and caching RRs, but rather on an active distribution of updates for all resolvers that showed interest in the respective records in the past, would be preferable. In this paper, we thus explore a publish-subscribe variant of DNS based on the Media-over-QUIC architecture, where we devise a strawman system and protocol proposal to enable pushing RR updates. We provide a prototype implementation, finding that DNS can benefit from a publish-subscribe variant: next to limiting update traffic, it can considerably reduce the time it takes for a resolver to receive the latest version of a record, thereby supporting use cases such as load balancing in content distribution networks. The publish-subscribe architecture also brings new challenges to the DNS, including a higher overhead for endpoints due to additional state management, and increased query latencies on first lookup, due to session establishment latencies.

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.

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.

In this paper, we propose a new rate control algorithm for conversational multimedia flows. In our approach, along with Real-time Transport Protocol (RTP) media packets, we propose sending redundant packets to probe for available bandwidth. These redundant packets are Forward Error Correction (FEC) encoded RTP packets. A straightforward interpretation is that if no losses occur, the sender can increase the sending rate to include the FEC bit rate, and in the case of losses due to congestion the redundant packets help in recovering the lost packets. We also show that by varying the FEC bit rate, the sender is able to conservatively or aggressively probe for available bandwidth. We evaluate our FEC-based Rate Adaptation (FBRA) algorithm in a network simulator and in the real-world and compare it to other congestion control algorithms.

Many residential and small business users connect to the Internet via home gateways, such as DSL and cable modems. The characteristics of these devices heavily influence the quality and performance of the Internet service that these users receive. Anecdotal evidence suggests that an extremely diverse set of behaviors exists in the deployed base, forcing application developers to design for the lowest common denominator. This paper experimentally analyzes some characteristics of a substantial number of different home gateways: binding timeouts, queuing delays, throughput, protocol support and others.

TurfNet is an internetworking architecture that enables communication among autonomous and heterogeneous network domains. The architecture uses a global identity namespace and does not require global addressing or a common internetworking protocol. It integrates the new concept of dynamic network composition with other recent architectural concepts, such as decoupling locators from identifiers. This paper analyzes whether the TurfNet naming and interdomain routing mechanisms can scale to networks of the size of the global Internet. To the authors' knowledge, this is one of the first scalability analyses of any next-generation internetworking proposal based on today's Internet AS topology. It adapts existing research results on the topology of the Internet's autonomous system graph and related results that quantify typical traffic patterns to construct a realistic model of an Internet-like TurfNet.

Most Internet telephony applications currently use either TCP or UDP to carry their voice-over-IP (VoIP) traffic. This choice can be problematic, because TCP is not well suited for interactive traffic and UDP is unresponsive to congestion. The IETF has recently standardized the new Datagram Congestion Control Protocol (DCCP). DCCP has been designed to carry media traffic and is congestion-controlled. This paper experimentally evaluates the voice quality that Internet telephony calls achieve over prototype implementations of basic DCCP and several DCCP variants, under different network conditions and with different codecs. It finds that the currently-specified DCCP variants perform less well than expected when compared to UDP and TCP. Based on an analysis of these results, the paper suggests several improvements to DCCP and experimentally validates that a prototype implementation of these modifications can significantly increase voice quality.

The Internet consists of independent networks that belong to different administrative domains and vary in scope from personal area networks, private home networks, corporate networks to ISP and global operator networks. These networks may employ different technologies, communications mediums, addressing realms and may have widely different capabilities. The coming years will add a significant level of dynamic behavior, such as mobile nodes and moving networks, which the Internet must support. At the same time, there is a need to address the increasing levels of harmful traffic and denial-of-service attacks. The existing Internet architecture does not support dynamic behavior or secure communication to a sufficient degree. This paper outlines a node-identity-based internetworking architecture that allows heterogeneous networks to work together without loss of functionality. Some of techniques employed in this architecture include reliance on cryptographic node identifiers, identity routers and localized addressing realms.

The Internet is currently evolving beyond what its architecture can support. Often, the mechanisms that allow the Internet to adapt to increasingly conflicting sets of new requirements break some of its basic design principles and can thus severely interfere with end-toend communication. This paper recognizes that increased autonomy of network regions is a key requirement for future internetworking. It outlines a new internetworking architecture that enables interoperation among a set of autonomous, heterogeneous network domains. The architecture is based on a global identity space and does not require global addressing or a shared internetworking protocol. It integrates the new concept of dynamic network composition with other recent architectural concepts, such as decoupling locators from identifiers. 1.

Vehicular ad hoc networks (VANETs) enable new applications by providing self-organizing vehicle-to-vehicle and vehicle-to-roadside communication. Some of these applications require reliable, in-order data delivery across end-to-end connections. The performance of a vehicular transport protocol (VTP) that provides such a service depends on its ability to adapt quickly to the varying path characteristics of highly dynamic environments. This paper studies path characteristics of VANETs in highway scenarios. An analytical evaluation derives upper bounds on the expected connectivity and disruption duration. Simulations validate these results and study further metrics, such as packet loss, packet reordering and round trip times. The paper also briefly outlines a preliminary VTP design that incorporates these analytical results.

The Internet is currently evolving beyond what its architecture can support. Often, the mechanisms that allow the Internet to adapt to increasingly conflicting sets of new requirements break some of its basic design principles and can thus severely interfere with end-to-end communication. This paper recognizes that increased autonomy of network regions is a key requirement for future internetworking. It outlines a new internetworking architecture that enables interoperation among a set of autonomous, heterogeneous network domains. The architecture is based on a global identity space and does not require global addressing or a shared internetworking protocol. It integrates the new concept of dynamic network composition with other recent architectural concepts, such as decoupling locators from identifiers.

Providing end-to-end communication in heterogeneous internetworking environments is a challenge. Two fundamental problems are bridging between different internetworking technologies and hiding of network complexity and differences from both applications and application developers. This paper presents abstraction and naming mechanisms that address these challenges in the Ambient Networks project. Connectivity abstractions hide the differences of heterogeneous internetworking technologies and enable applications to operate across them. A common naming framework enables end-to-end communication across otherwise independent internetworks and supports advanced networking capabilities, such as indirection or delegation, through dynamic bindings between named entities

This paper presents the idletime scheduler; a generic, kernel-level mechanism for using idle resource capacity in the background without slowing down concurrent foreground use. Many operating systems fail to support transparent background use and concurrent foreground performance can decrease by 50% or more. The idletime scheduler minimizes this interference by partially relaxing the work conservation principle during preemption intervals, during which it serves no background requests even if the resource is idle. The length of preemption intervals is a controlling parameter of the scheduler: short intervals aggressively utilize idle capacity; long intervals reduce the impact of background use on foreground performance. Unlike existing approaches to establish prioritized resource use, idletime scheduling requires only localized modifications to a limited number of system schedulers. In experiments, a FreeBSD implementation for idletime network scheduling maintains over 90% of foreground TCP throughput, while allowing concurrent, high-rate UDP background flows to consume up to 80% of remaining link capacity. A FreeBSD disk scheduler implementation maintains 80% of foreground read performance, while enabling concurrent background operations to reach 70% throughput.