• Journal of KIISE:Information Networking
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• v.37 no.3
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• pp.175-186
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• 2010

Due to the emergence of new application programs and the fast growth of Internet users, Internet routers are required to provide the quality of services according to the class of input packets, which is identified by wire-speed packet classification. For a pre-defined rule set, by performing multi-dimensional search using various header fields of an input packet, packet classification determines the highest priority rule matching to the input packet. Efficient packet classification algorithms have been widely studied. Tuple pruning algorithm provides fast classification performance using hash-based search against the candidate tuples that may include matching rules. Bloom filter is an efficient data structure composed of a bit vector which represents the membership information of each element included in a given set. It is used as a pre-filter determining whether a specific input is a member of a set or not. This paper proposes new tuple pruning algorithms using Bloom filters, which effectively remove unnecessary tuples which do not include matching rules. Using the database known to be similar to actual rule sets used in Internet routers, simulation results show that the proposed tuple pruning algorithm provides faster packet classification as well as consumes smaller memory amount compared with the previous tuple pruning algorithm.

• Journal of KIISE:Information Networking
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• v.35 no.6
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• pp.482-496
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• 2008

Packet classification in the Internet routers requires multi-dimensional search for multiple header fields for every incoming packet in wire-speed, hence packet classification is one of the most important challenges in router design. Hierarchical packet classification is one of the most effective solutions since search space is remarkably reduced every time a field search is completed. However, hierarchical structures have two intrinsic issues; back-tracking and empty internal nodes. In this paper, we propose a new hierarchical packet classification algorithm which solves both problems. The back-tracking is avoided by using the set-pruning and the empty internal nodes are avoided by applying the binary search tree. Simulation result shows that the proposed algorithm provides significant improvement in search speed without increasing the amount of memory requirement. We also propose an optimization technique applying controlled rule copy in set-pruning.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9B
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• pp.577-588
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• 2007

The rapid growth of the Internet has stimulated the development of various new applications and services, and the service providers and the Internet users now require different levels of service qualities rather than current best-effort service which treats all incoming packet equally. Therefore, next generation routers should provide the various levels of services. In order to provide the quality of services, incoming packets should be classified into flows according to pre-defined rules, and this should be performed for all incoming packets in wire-speed. Packet classification not only involves multi-dimensional search but also finds the highest priority rule among all matching rules. Area-based quad-trie is a very good algorithm that constructs a two-dimensional trie using source and destination prefix fields. However, it performs the linear search for the prefix length, and hence it does not show very good search performance. In this paper, we propose to apply binary search on length to the area-based quad-trie algorithm. In improving the search performance, we also propose two new algorithms considering the priority of rules in building the trie.

• Journal of Internet of Things and Convergence
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• v.3 no.1
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• pp.9-11
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• 2017

Recently, with the widespread use of the Internet and mobile devices, the number of attacks by hackers using the network is increasing. When connecting a network, packets are exchanged and communicated, which includes various information. We analyze the information of these packets using hierarchical clustering analysis and classify normal and abnormal packets to detect attacks. With this analysis method, it will be possible to detect attacks by analyzing new packets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1285-1296
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• 2011

Packet classification is one of the basic and important functions of the Internet routers, and it became more important along with new emerging application programs requiring real-time transmission. Since packet classification should be accomplished in line-speed on each incoming input packet for multiple header fields, it becomes one of the challenges in designing Internet routers. Various packet classification algorithms have been proposed to provide the high-speed packet classification. Hierarchical approach achieves effective packet classification performance by significantly narrowing down the search space whenever a field lookup is completed. However, hierarchical approach involves back-tracking problem. In order to solve the problem, set-pruning trie and grid-of-trie algorithms are proposed. However, the algorithm either causes excessive node duplication or heavy pre-computation. In this paper, we propose a smart set-pruning trie which reduces the number of node duplication in the set-pruning trie by the simple merging of the lower-level tries. Simulation result shows that the proposed trie has the reduced number of copied nodes by 2-8% compared with the set-pruning trie.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2A
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• pp.79-85
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• 2006

Generally, it is essential that high-speed routers, switches, and network security appliances should have an efficient packet classification scheme in order to achieve the high-speed packet forwarding capability. For the multi-gigabit packet-processing network equipment the high-speed content search hardware such as TCAM and search engine is recently used to support the content-based packet inspection. During the packet classification process, hundreds and thousands of rules are applied to provide the network security policies regarding traffic screening, traffic monitoring, and traffic shaping. In addition, these rules could be dynamically changed during operations of systems if anomaly traffic patterns would vary. Particularly, in the high-speed network, an efficient algorithm that updates and reorganizes the packet classification rules is critical so as not to degrade the performance of the network device. In this paper, we have proposed an efficient update algorithm using a partial-ordering that can relocate the dynamically changing rules at the TCAM. Experimental results should that our algorithm does not need to relocate existing rules feature until 70$\%$ of TCAM utilization.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1773-1776
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• 2005

본 논문에서는 운영체제 측면에서 QoS를 보장하기 위해 우선순위 기반의 네트워크 프로토콜 처리 기법을 제안한다. 제안된 기법에서는 우선순위에 따라 네트워크 패킷을 분류하고 프로토콜을 처리한다. 이를 위해 패킷분류기(Packet Classifier)와 프로토콜엔진(Protocol Engine)을 포함하는 QPF(QoS Provisioning Framework)를 설계하고 리눅스 커널 내부에 구현하였다. 과거의 인터럽트 기반의 방식에서는 네트워크 패킷이 선착순(first-in first-out)으로 처리되어 응용 프로그램에서 요구하는 QoS를 보장하기 어려우며, 또한 항상 네트워크 패킷의 처리가 응용 프로그램보다 우선적으로 처리되어 수신교착상태(Receive Livelock) 등의 문제가 발생한다. 본 논문에서 제안하는 QPF는 네트워크 패킷을 우선순위에 따라 처리함은 물론 네트워크 처리에 사용되는 CPU 시간을 조절할 수 있어 위와 같은 문제를 효과적으로 해결할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.339-348
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• 2004

Packet classification is an important factor to support various services such as QoS guarantee and VPN for users in Internet. Packet classification is a searching process for best matching rule on rule tables by employing multi-field such as source address, protocol, and port number as well as destination address in If header. In this paper, we propose hardware based packet classification algorithm by employing tree bitmap of multi-bit trio. We divided prefixes of searching fields and rule into multi-bit stride, and perform a rule searching with multi-bit of fixed size. The proposed scheme can reduce the access times taking for rule search by employing indexing key in a fixed size of upper bits of rule prefixes. We also employ a marker prefixes in order to remove backtracking during searching a rule. In this paper, we generate two dimensional random rule set of source address and destination address using routing tables provided by IPMA Project, and compare its memory usages and performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2B
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• pp.91-97
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• 2006

As increasing the network bandwidth, the threat of a network also increases with emerging various new services. For a high-performance network security, It is generally used that high-speed packet classification methods which employ hardware like TCAM. There needs an method using these devices efficiently because they are expensive and their capacity is not sufficient. In this paper, we propose an efficient packet classification using a Ternary-CAM(TCAM) which is widely used device for high-speed packet classification in which we have applied Snort rule set for the well-known intrusion detection system. In order to save the size of an expensive TCAM, we have eliminated duplicated IP addresses and port numbers in the rule according to the partitioning of a table in the TCAM, and we have represented negation and range rules with reduced TCAM size. We also keep advantages of low TCAM capacity consumption and reduce the number of TCAM lookups by decreasing the TCAM partitioning using combining port numbers. According to simulation results on our TCAM partitioning, the size of a TCAM can be reduced by upto 98$\%$ and the performance does not degrade significantly for high-speed packet classification with a large amount of rules.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.769-771
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• 2004

급증하는 무선 인터넷 서비스 요구에 효과적으로 대처하기 위해서는 휴대성과 이동성이 보장되며 저렴한 요금을 지향하는 새로운 형태의 무선데이터 시스템인 초고속 휴대용 인터넷(High-speed Portable Internet: HPi) 시스템이 요구된다. ETRI(Electronics and Telecommunications Research Institute)에서 독자 개발 중인 HPi 시스템은 IEEE 802.16 표준을 기반으로 서비스 분류에 따른 차별적인 서비스를 제공한다. 이동 단말이 서로 다른 셀 영역을 이동할 경우 핸드오버를 수행하고 핸드오버 동안의 패킷 유실 발생을 방지하기 위하여 이전 AP에서 패킷 버퍼링을 해야한다. 따라서 핸드오버 동안에 HPi에서 제공하는 서비스 분류에 따른 차별적인 품질을 보장하기 위하여 서비스 클래스에 따른 차별적인 패킷 버퍼링 메커니즘이 필요하다. 본 논문에서는 HPi에서의 핸드오버 시 차별적인 서비스 품질 보장을 위한 패킷 버퍼링 메커니즘을 제안한다.