Forward Throughput Research Articles

OFaaS: OpenFlow Switch as a Service for Multi Tenant Slicing in SD-CDN

In Software Defined-Content Delivery Networks (SD-CDN), the policies of tenants such as Youtube, Netflix, Office 365, etc. are not the same due to having different 5G traffic requirements for such contents as enhanced Mobile Broadband (eMBB), ultra-reliable low-latency (URLLC) and massive machine-type communication (mMTC). This leads SD-CDN multi-tenant slicing to provide different services with limited network resources, where each tenant can functionally manage their own virtual slice of a physical component according to service level agreements (SLAs). However, they are not permitted to dynamically configure their own components. Therefore, the physical end-to-end configuration of all edge devices causes extra hardware and bandwidth costs. Although software as a service (SaaS) is more preferred to handle cost-efficiency on a switch configuration that increases forwarding throughput (Mbps) with a less number of physical components in SD-CDN, the edge devices can be only served as infrastructure as a service (IaaS) currently. This motivation leads us to serve the switch as a service that includes both IaaS and SaaS characteristics. Therefore, we propose an OpenFlow as a service (OFaaS) design where each tenant has flow management and switch configuration permissions on their own virtual slice. In flow management, we define a novel Service Oriented Architecture (SOA) to orchestrate OFaaS driven topology by isolating each tenant from physical complexity. Here, each tenant can dynamically alter QoS on a flow and load balance between a sub-set of contents via OpenFlow protocol. In switch configuration; a novel OFaaS Management Algorithm for a multi-tenant slicing increases the number of tenants served per OpenFlow switch thanks to OFaaS design. It enables an end-to-end configuration via the NETCONF protocol with a novel YANG model of OFaaS. According to performance evaluation; OFaaS has the same forwarding throughput as conventional IaaS based OpenFlow switch for a homogenous content, whereas it has 71% more forwarding throughput (Mbps) and it has 40% more cost-efficient than conventional one for a heterogeneous content with $17 savings per tenant.

BFAST: High-Speed and Memory-Efficient Approach for NDN Forwarding Engine

Named data networking (NDN) is a future Internet architecture that directly emphasizes accessible content by assigning each piece of content a unique name. Data transmission in NDN is realized via name-based routing and forwarding. Name-based forwarding information base (FIB) usually has much more and longer prefixes than IP-based ones, and therefore, name-based forwarding brings more challenges on the NDN router in terms of high forwarding throughput, low memory consumption, and fast FIB update. In this paper, we present an index data structure called BFAST for the name-based FIB. BFAST is designed based on a basic hash table, it employs a counting Bloom filter to balance the load among hash table slots, so that the number of items in each non-empty slot is close to 1, leading to low searching time in each slot. Meanwhile, the first-rank-indexed scheme is proposed to effectively reduce the massive memory consumption required by the pointers in all the hash table slots. Evaluation results show that, for the longest prefix match FIB lookup, BFAST achieves a speed of 2.14 MS/S using one thread, and meanwhile, the memory consumption is reasonably low. By leveraging the parallelism of today’s multi-core CPU, BFAST arrives at an FIB lookup speed of 33.64 MS/S using 24 threads, and the latency is around $0.71~\mu s$ .

Development of 100 MHz Bandwidth Testbed toward IMT-Advanced and Experimental Results Including Rotational OFDM and Twin Turbo Decoder Transmission Performances

Aiming at actual evaluation of IMT-Advanced system performance using field tests, this paper develops an IMT-Advanced testbed system with a transmission bandwidth of 100MHz. Taking into account recent advances in research and development of an IMT-Advanced system, orthogonal frequency division multiplexing (OFDM) with multiple-input multiple-output (MIMO) are also promising technologies in IMT-Advanced. In addition, in order to meet the requirements for IMT-Advanced, the system seems to have a bandwidth of about 100MHz with the aid of MIMO transmission. The developed system is based on the above more reliable prediction compared with previous studies, and the goals of this development are to provide a more realistic transmission performance, judgment criteria for operators introducing new air interfaces, and to explore new applications. This paper also presents the experimental results of rotational OFDM (R-OFDM) and twin turbo (T2) decoder implemented in the testbed and demonstrates that our proposals are better than the conventional schemes in actual radio transmission. Both physical layer technologies have been proposed by the authors, however, the previous works are only predicated on computer simulation. In this paper, the proposals are experimentally evaluated by distorting the transmitted signal on radio waves with a fading simulator and additional noise generator. When the packet error rate performance is measured, the measurement results are verified to be in good agreement with the simulation results. The experimental results also demonstrate that the R-OFDM can reduce the required carrier to the interference power ratio (CIR) of OFDM by about 1.1dB in single-input single output (SISO) multi-path fading channel. In addition, it becomes clear that the T2 decoder is better than the turbo decoder in error correction, and the required CIR reduction achieves about 0.8dB in SISO AWGN channel. The throughput performances are also measured with different modulation and coding conditions, and the measured forward throughput in the SISO AWGN channel achieves up to 373.6Mbps. In addition, by use of 2×2 MIMO transmission, the measurements results substantiate that throughput of 512.7Mbps can be realized even in the multi-path fading condition.

Optimizing the packet forwarding throughput of multi-hop wireless chain networks

In the literature, it has been shown that due to signal interferences between neighboring stations, the maximum packet forwarding throughput of a N-hop wireless chain network decreases as N increases and is only 1/ N of the wireless bandwidth. This 1/ N trend continues until the throughput finally stabilizes at only 1/5 or even less when N becomes large. To solve this problem, this paper proposes an approach that optimizes the forwarding throughput of a wireless chain network. In this approach, which we call the ‘two-frequency scheme’, the wireless interface cards of some nodes in the wireless chain network will swap their operating frequency channels between two different channels to avoid interferences. Using this approach, even when N is large, the forwarding throughput can be cost-effectively improved to 1/2, which is the optimal forwarding throughput that can be achieved by a half-duplex wireless interface.

Scalable multi-QoS IP+ATM switch router architecture

This article proposes a scalable multi-QoS IP+ATM switch router architecture. The proposed switch router is based on a core ATM switching system with multi-QoS capability. Forwarding engines and a routing engine are attached in front of the line cards of the ATM switching system. The FEs and RE are interconnected with each other via internal VCs. A novel longest matching algorithm is employed at the FE to achieve packet forwarding at wire-speed of OC-12c rate (622.08 Mb/s). Wire-speed unicast and multicast packet forwarding are performed using point-to-point and point-to-multipoint VCs in a unified way. Because FEs and RE are decoupled from the base ATM switching system, the full spectrum of ATM QoS capability is nicely applied for IP QoS control with a packet classification at the edge of the network. The core switching fabric is scalable from 40 to 160 Gb/s capacity (371 MPPS in terms of packet forwarding throughput). Feedback rate control is employed at each line card to eliminate congestion in the high-speed core switching fabric even with a small amount of buffer.