David R. Oran

Named data networking on a router: fast and dos-resistant forwarding with hash tables

Named data networking (NDN) is a new networking paradigm using named data instead of named hosts for communication. Implementation of scalable NDN packet forwarding remains a challenge because NDN requires fast variable-length hierarchical name-based lookup, per-packet data plane state update, and large-scale forwarding tables. In this paper, we review various design options for a hash table-based NDN forwarding engine and propose a design that enables fast forwarding while achieving DoS (Denial-of-Service) resistance. Our forwarding engine features (1) name lookup via hash tables with fast collision-resistant hash computation, (2) an efficient FIB lookup algorithm that provides good average and bounded worst-case FIB lookup time, (3) PIT partitioning that enables linear multicore speedup, and (4) an optimized data structure and software prefetching to maximize data cache utilization. We have implemented an NDN data plane with a software forwarding engine on an Intel Xeon-based line card in the Cisco ASR 9000 router. By simulation with names extracted from the IR-Cache traces, we demonstrate that our forwarding engine achieves a promising performance of 8.8 MPPS and our NDN router can forward the NDN traffic at 20 Gbps or higher.

Streaming video over HTTP with consistent quality

In conventional HTTP-based adaptive streaming (HAS), a video source is encoded at multiple levels of constant bitrate representations, and a client makes its representation selections according to the measured network bandwidth. While greatly simplifying adaptation to the varying network conditions, this strategy is not the best for optimizing the video quality experienced by end users. Quality fluctuation can be reduced if the natural variability of video content is taken into consideration. In this work, we study the design of a client rate adaptation algorithm to yield consistent video quality. We assume that clients have visibility into incoming video within a finite horizon. We also take advantage of the client-side video buffer, by using it as a breathing room for not only network bandwidth variability, but also video bitrate variability. The challenge, however, lies in how to balance these two variabilities to yield consistent video quality without risking a buffer underrun. We propose an optimization solution that uses an online algorithm to adapt the video bitrate step-by-step, while applying dynamic programming at each step. We incorporate our solution into PANDA -- a practical rate adaptation algorithm designed for HAS deployment at scale.

An improved hop-by-hop interest shaper for congestion control in named data networking

Hop-by-hop interest shaping has been proposed as a viable congestion control mechanism in Named Data Networking (NDN). Interest shaping exploits the strict receiver-driven traffic pattern and the symmetric bidirectional forwarding in NDN to control the returning data rate. In this paper, we point out that both interests and contents contribute to congestion and their interdependence must be considered in any interest shaping algorithm. We first analyze this issue mathematically by formulating it as an optimization problem to obtain the optimal shaping rate. Then a practical interest shaping algorithm is proposed to achieve high link utilization without congestive data loss. We further note that flow differentiation in NDN is complicated and design our scheme independently of traffic flows. We demonstrate our hop-by-hop interest shaper in conjunction with simple Additive-Increase-Multiplicative-Decrease (AIMD) clients using the ns3-based NDN simulator (ndnSIM). Our results show that the proposed shaping algorithm can effectively control congestion and achieve near-optimal throughput.

Named data networking on a router: forwarding at 20gbps and beyond

Named data networking (NDN) is a new networking paradigm using named data instead of named hosts for communication. Implementation of scalable NDN packet forwarding remains a challenge because NDN requires fast variable-length hierarchical name-based lookup, per-packet data plane state update, and large-scale forwarding tables. We have designed and implemented an NDN data plane with a software forwarding engine on an Intel Xeon-based line card in a Cisco ASR9000 router. In order to achieve high-speed forwarding, our design features (1) name lookup via hash tables with fast collision-resistant hash computation, (2) an efficient and secure FIB lookup algorithm that provides good average and bounded worst-case FIB lookup time, (3) PIT partitioning that enables linear multi-core speedup, and (4) an optimized data structure and software prefetching to maximize data cache utilization. In this demonstration, we showcase our NDN router implementation on the ASR9000 and demonstrate that it can forward real NDN traffic at 20Gbps or higher.

Secure Fragmentation for Content-Centric Networks

Content-Centric Networking (CCN) is a communication paradigm that emphasizes content distribution. Named-Data Networking (NDN) is an instantiation of CCN, a candidate Future Internet Architecture. NDN supports human-readable content naming and router-based content caching which lends itself to efficient, secure, and scalable content distribution. Because of NDNs fundamental requirement that each content object must be signed by its producer, fragmentation has been considered incompatible with NDN since it precludes authentication of individual content fragments by routers. The alternative is to perform hop-by-hop reassembly, which incurs prohibitive delays. In this paper, we show that secure and efficient content fragmentation is both possible and even advantageous in NDN and similar content-centric network architectures that involve signed content. We design a concrete technique that facilitates efficient and secure content fragmentation in NDN, discuss its security guarantees and assess performance. We also describe a prototype implementation and compare performance of cut-through with hop-by-hop fragmentation and reassembly.

Toward terabyte-scale caching with SSD in a named data networking router

Named Data Networking (NDN) routers can cache previously forwarded Data packets, and those can be reused when a matching Interest packet arrives. Unlike traditional IP routers and HTTP caches that exist as separate devices, designing a scalable NDN router is a new challenge because it should perform fast forwarding and massive-scale caching at the same time. This paper proposes a design of an NDN router with unique forwarding and caching mechanisms featuring terabyte-scale caching with solid-state drives (SSD) while still forwarding packets at line speed.

Communication patterns for web interaction in named data networking

Named Data Networking (NDN) is an information-centric networking architecture that has recently attracted significant attention. At first glance NDNs pure pull-based communication model seems to match the request-reply mechanics of HTTP/Web interactions. In reality, modern Web communication patterns involve passing client-side information and/or application state in requests. As we attempt to apply these communication patterns to NDN, we find that it is not immediately clear how to use NDN effectively. In this paper, we examine multiple diverse approaches to running modern Web-like applications over the NDN communication architecture, discussing advantages and drawbacks of each of the proposed approaches. Our primary goal is to start a focused discussion of how NDN can support modern Web communication patterns effectively.

Video quality assessment in the age of internet video: technical perspective

authors call buffering) cause the most dramatic effects on user engagement, particularly for “live” content such as sports and news. At some level, video stalls are analogous to major failures or glitches of earlier systems, and cause the most profound dissatisfaction among users. Stalls are a widespread phenomenon new to Internet video, and stem from the timeand locationvarying quality of Internet bandwidth, packet loss patterns, and congestive overload. The protocols used today for adaptive streaming of video are still primitive and the subject of both active research and standardization work. As they improve, the frequency and severity of stalls should decrease, no longer masking the magnitude of other effects such as encoding quality, variations in quality due to adaptation algorithms, and join time. Other results in this work must be seen in the light of the dominance of stalls compared to the other phenomena the authors evaluate. Despite the ubiquity and popularity of Netflix and YouTube, we are still in the early days of the Internet video phenomenon. As with VoIP, users initially were delighted to the point of astonishment that the system worked at all, since it provided access to a significantly larger library of content, at lower cost, greater convenience, and on more devices than available in the “walled gardens” offered by broadcasters, satellite, and cable systems. Today we are in the hyper-growth phase, where users expect the systems to have high availability but not necessarily reach the quality of the legacy systems. It will not be long before quality as well is competitive with or even in some cases exceeds non-Internet systems. We will need mature measurement methodologies to support these systems. This work is a good start.

Erasure Coded Storage on a Changing Network: The Untold Story

As faster storage devices become commercially viable alternatives to disk drives, the network is increasingly becoming the bottleneck in achieving good performance in distributed storage systems. This is especially true for erasure coded storage, where the reconstruction of lost data can significantly encumber the system. Thus, a significant amount of research has focused on reducing the amount of data transferred during this repair process. However, in most cases the network is assumed to have a uniform static structure. One reason behind this is that many of the state of the art codes have a fixed repair mechanism or are constrained in the choice of repair strategies, therefore in theory benefit less from being network aware. We propose a general mechanism that explores the space of possible repairs and examine how much different types of erasure codes benefit by being network aware. We show significant gains for three erasure codes using both theoretical modeling and simulation results. We also consider the practical applicability of our proposed mechanism by limiting the search space to repairs that have the potential to be minimal cost and present a case study for RLNC, a class of flexible codes.

Bibliography of recent publications on computer communication

ACM Operating Systems Review computer communication s Computer Communication Review Computer Networks and ISDN System s ConneXions Distributed Computing Electronic Networking IEEE Journal on Selected Areas of Communications IEEE Network Magazine IEEE Transactions on Communication s IEEE/ACM Transactions on Networking Inter-networkinglnternet Requests for Comment (RFCs ) Journal of High Speed Networks networks, an international journa l