Evaluating and Optimizing IP Lookup on Many core Processors

International audienceIn recent years, there has been a growing interest in multi/many core processors as a target architecture for high performance software router. Because of its key position in routers, hardware IP lookup implementation has been intensively studied with TCAM and FPGA based architecture. However, increasing interest in software implementation has also been observed. In this paper, we evaluate the performance of software only IP lookup on a many core chip, the TILEPro64 processor. For this purpose we have implemented two widely used IP lookup algorithms, DIR-24-8-BASIC and Tree Bitmap. We evaluate the performance of these two algorithms over the TILEPro64 processor with both synthetic and real-world traces. After a detailed analysis, we propose a hybrid scheme which provides high lookup speed and low worst case update overhead. Our work shows how to exploit the architectural features of TILEPro64 to improve the performance, including many optimization in both single-core and parallelism aspects. Experiment results show by using only 18 cores, we can achieve a lookup throughput of 60Mpps (almost 40Gbps) with low power consumption, which demonstrates great performance potentials in many core processor

Towards practical use of Bloom Filter based IP lookup in operational network

International audienceBloom Filter is a widely used data structure in computer science. It enables memory efficient and fast set membership queries. Bloom filter-based solutions have been proposed in the past decade for lookup in forwarding tables of backbone routers [2]. However, the main shortcomings of using Bloom Filters for lookup lie in the absence of support for deletion operations that are needed to update the forwarding tables. Counting Bloom Filter supporting deletion has therefore to be used, increasing significantly the memory requirement. Moreover, Counting Bloom Filter suffers from both false positive and false negative. In this paper, we propose to solve the issue with deletion of Bloom Filters by using a Withdrawal To annOuncement (WTO) mapping that replaces withdrawal with announcements, transforming deletions into additions or record changes. Experimental evaluation show that the proposed techniques improve largely the performance of Bloom Filter used for forwarding lookup and open way for the use of Bloom Filters in real operational settings

Mnemonic Lossy Counting: An Efficient and Accurate Heavy-hitters Identification Algorithm

International audienceIdentifying heavy-hitter traffic flows efficiently and accurately is essential for Internet security, accounting and traffic engineering. However, finding all heavy-hitters might require large memory for storage of flows information that is incompatible with the usage of fast and small memory. Moreover, upcoming 100Gbps transmission rates make this recognition more challenging. How to improve the accuracy of heavy-hitters identification with limited memory space has become a critical issue. This paper presents a scalable algorithm named Mnemonic Lossy Counting (MLC) that improves the accuracy of heavy-hitters identification while having a reasonable time and space complexity. MLC algorithm holds potential candidate heavy-hitters in a historical information table. This table is used to obtain tighter error bounds on the estimated sizes of candidate heavy-hitters. We validate the MLC algorithm using real network traffic traces, and we compared its performance with two state-of-theart algorithms, namely Lossy Counting (LC) and Probabilistic Lossy Counting (PLC). The results reveal that: 1) with same set of parameters and memory usage, MLC achieves between 31.5% and 6.67% fewer false positives than LC and PLC. 2) MLC and LC have a zero false negative ratio, whereas 38% of the cases PLC has a non-zero false negatives and PLC can miss up to 4.4% of heavy-hitters. 3) MLC has a slightly lower memory cost than LC during the first few windows and its memory usage decreases with time, when PLC memory usage declines sharply. 4) MLC has similar runtime than LC, and smaller time than PLC

Efficient Traffic Flow Measurement for ISP Networks

International audienceTraffic flow measurement is of great importance to ISPs for various network engineering tasks. However, directly measuring traffic flows of the whole ISP network is greatly time and cost-consuming. An interesting problem is that how one can obtain the traffic flows of the whole ISP network by just monitoring a small fraction of links. Previous works view the problem as Vertex Cover problem. They suffer from high time complexity. Besides, using these methods, the monitoring of some links is redundant. Different from these works, we study the problem from the perspective of edges and propose two models. The first model, Extended Edge Cover model, is based on the key observation of flow conservation. This method can determine the minimum set of monitored links, which are 30% less than that of previous works. The second model, shared-path model, utilizes the routing information and topological property of the network. It is more suitable when the monitoring resources are limited but one still wants to measure a large part of the networks. Using this method, one can measure 85% of the network by monitoring 5% of links. Finally, we evaluate the performance of the two models through extensive simulations. The experimental results show the effectiveness and robustness of the two models

PEARL: a programmable virtual router platform

International audienceProgrammable routers supporting virtualization are a key building block for bridging the gap between new Internet protocols and their deployment in real operational networks. This article presents the design and implementation of PEARL, a programmable virtual router platform with relatively high performance. It offers high flexibility by allowing users to control the configuration of both hardware and software data paths. The platform makes use of fast lookup in hardware and software exceptions in commodity multicore CPUs to achieve highspeed packet processing. Multiple isolated packet streams and virtualization techniques ensure isolation among virtual router instances

An Accurate and Efficient 3-Phase Measurement Method for IP Traffic Flow on High Speed Link

International audienceFlow metrics are critical for protocol research, anomaly detection, network operation and application deployment. There are great challenges to match every packet into millions of flows in high speed network link. A 3-phase measurement method for IP traffic flow is proposed in this paper. The packets are captured and classified into the flows through hash table, search tree and linear table with this approach. The traffic measurement systems in general purpose CPU platform and network processor platform with this method have been implemented and deployed in backbone links. The experiment on OC-48 backbone shows the average length search path for each packet is 7.7. Average process times of mapping successfully and unsuccessfully are about 1.3 μs and 1.8 μs respectively at the length of search path 350. Traffic matrix, host behavior and other metrics can been easily deduced with our approach

Efficient soft QoS guarantee in mobile ad hoc networks

International audienceMore and more Quality of Service (QoS) sensitive applications, such as streaming media, high bandwidth content distribution and VoIP, will be deployed in Mobile Ad hoc Networks (MANETs) as part of the pervasive computing realization. However, traditional QoS guarantee technologies cannot be used directly in MANETs due to the dynamic network environment. This paper proposes a QoS management mechanism combining Caching and Backup Service Paths (CBSP) and an Enhanced CBSP (ECBSP) for soft QoS guarantee in MANETs. In CBSP, Service Provider Nodes (SPNs) with distinct Service Paths (SPs) providing the required service are found in the MANET during the service discovery phase. The client node then selects one SP to get the service and the other SPs as Backup Service Paths (BSPs). If the serving SP fails to serve the client node, the client node can handover quickly to a BSP and consume the resource in its cache during the handover operation in order to avoid service interruption. In ECBSP, the required data are further divided into several segments and transmitted concurrently to the client node through different SPs for enhanced availability. Simulation experiments in ns2 show that CBSP/ECBSP can improve the performance of applications in MANETs effectively