• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.219-224
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• 2008

In the c-DSDV routing protocol proposed to improve the scalability of DSDV, clusterheads manage a routing table that has only clusterheads as potential destinations and flood update request message to its neighbor clusterheads periodically or at the time of topology change. Accordingly, the convergence range of topology change by a single update request message was expanded nine times as wide as that of DSDV, increasing routing correctness; however, c-DSDV suffers from the congestion of clusterheads since data packets always go through clusterheads of the clusters on the routing path. To improve this problem, we propose an adaptive routing scheme that judges if detouring clusterhead is possible on the fly while packets are forwarded. As a result, a routing path length is shortened and an end-to-end delay is improved by the reduced queue length. It shows that the end-to-end delay is reduced by almost 40% through simulation.

• Journal of the Korea Society of Computer and Information
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• v.6 no.1
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• pp.74-81
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• 2001

In this paper. the architecture of a high-speed ATM router using ATM switch is studied and the performance of the high-speed ATM router is analyzed through simulation. The high-speed ATM router using ATM switch is able to reduce the load of router and the processing time of a packet in the router. The size of router buffers has been studied through simulation processes for the analysis of performance capacity in due course of making changes in routing time(RT), which is the performance capacity parameters of high-speed ATM routers, flow table size(FS), flow live time(FT) and input circuit efficiencies. The result of this study can be used as the source material for analyzing the suitability of equipment in upgrading networks and applying high-speed ATM routers by using ATM switches.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.3 no.1
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• pp.15-24
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• 2004

'The delay and control overhead during route discovery for destinations outside ad hoc networks are major obstacle to achieving scalability in the Internet. To solve this issue, we propose a novel route discovery scheme equipped with two augmented functions. In this paper, the Internet gateway maintains an address cache of Internet nodes frequently accessed from the ad hoc network and replies with an extended Route Response (RREP) message to the Route Request (RREQ) message based on its routing table and the address cache called EXIT(EXternal node Information Table). These augmented functions make the source node determine the location of the destination as fast as possible. Through simulations, the proposed route discovery scheme using both EXIT and extended RREP message shows considerable' reduction in both route discovery time and control message overhead.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.728-735
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• 2003

It is a mainly issue that provide mobility smoothly in Mobile IP networks. The IP mobility support being standardized in the IETF utilized tunneling of IP packets from a home agent to foreign agent and utilized reverse tunneling of IP packets from foreign agent to home agent. In this paper, We propose that solve the triangular routing problem in IP mobility and that lessen the messages about IETF routing optimization. Through the Mobile Routing Table on the edge router, agent process the message instead of a end node when handoff occur and that lessen the routing path length by sending directly from FA to to Correspond Node's router. This action lessen the message occurrence frequency and the packet drop. We compare the standard IP, Routing Optimization of Mobile IP, Wu's method and the proposed algorithm. Finally, the simulation results are presented.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.3
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• pp.46-52
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• 2008

BGP is an exterior routing protocol which exchanges routing information between ASs in ISP or large networks. It is necessary for the BGP to provide traffic enforcement among ASs, for an End-to-End traffic engineering capability in the Internet. However, traditional BGP-4 is lack of end-to-end traffic engineering capability because the policy-based routing affects the traffic only between directly-connected neighbor ASs. This paper proposes an extended BGP routing algorithm to achieve an End-to-End traffic engineering capability. This new method does not require an additional BGP message type, nor change a structure of existing routing table. It only extended the operation of UPDATE message with AS_PATH attribute, which is well-known mandatory. Simulation shows that the new BGP algorithm improves the packet delay and packet loss without the problem of backward compatibility.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.1
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• pp.26-35
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• 1997

In this paper, a VHDL implementation method for the internet protocol (IP) placed on top of ATM, so called IP over ATM, is presented. The proposed implementation method employs a parallel processing architecture to reduce the processing time and offers 155.52Mbps (STM-1) interface with the full-duplex mode for the ATM-based network. Furthermore, in order to minimize the search time for the table look-up, a LANCAM-based structure combining the routing table with the ATMARP table is proposed. The VHDL simulation results show that this proposed method can transmit (receive) at 155.52Mbps with delays of 48.5 clocks (29.5clocks).

• Journal of Communications and Networks
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• v.9 no.4
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• pp.499-510
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• 2007

Shortest path tree(SPT) construction is essential in high performance routing in an interior network using link state protocols. When some links have new state values, SPTs may be rebuilt, but the total rebuilding of the SPT in a static way for a large computer network is not only computationally expensive, unnecessary modifications can cause routing table instability. This paper presents a new update algorithm, dynamic shortest path tree(DSPT) that is computationally economical and that maintains the unmodified nodes mostly from an old SPT to a new SPT. The proposed algorithm reduces redundancy using a dynamic update approach where an edge becomes the significant edge when it is extracted from a built edge list Q. The average number of significant edges are identified through probability analysis based on an arbitrary tree structure. An update derived from significant edges is more efficient because the DSPT algorithm neglect most other redundant edges that do not participate in the construction of a new SPT. Our complexity analysis and experimental results show that DSPT is faster than other known methods. It can also be extended to solve the SPT updating problem in a graph with negative weight edges.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.61-68
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• 2015

MANET has various vulnerability in wireless network and is more vulnerable in security because central management is not performed. In particular, routing attack may decrease performance of the overall network because the mobile node acts as a router. In this paper, we proposed authentication technique for improving the reliability of the network by increasing the integrity of the routing control packet and blocking effectively attacks that occur frequently in the inside. The proposed technique is consisted of two authentication methods of ZCN and N2N. ZCN authentication method is to elect CA nodes and monitor the role of the CA nodes. N2N authentication method is for an integrity check on the routing packets between nodes. Index key is determined by combining the hop count value to shared key table issued from CA in order to increase the robustness of the internal attack. Also, the overhead of key distribution was reduced by distributing a shared key to nodes certificated from CA. The excellent performance of the proposed method was confirmed through the comparison experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3B
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• pp.65-71
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• 2005

The primary function of the Internet routers is to forward incoming packets toward their final destinations. IP address lookup is one of the most important functions in evaluating router performance since IP address lookup should be performed in wire-speed for the hundred-millions of incoming packets per second. With CIDR, the IP prefixes of routing table have arbitrary lengths, and hence address lookup by exact match is no longer valid. As a result, when packets arrive, routers compare the destination IP addresses of input packets with all prefixes in its routing table and determine the most specific entry among matching entries, and this is called the longest prefix matching. In this paper, based on parallel multiple hashing and prefix grouping, we have proposed a hardware architecture which performs an address lookup with a single memory access.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.11
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• pp.1037-1053
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• 1991

Flooding is known to be an effective routing mechanism not only in circuit switched networks but also packet switched networks since it minimizes the time required for up calls and does not have to maintain routing tables or distance tables by periodically intercommunicating among all the network nodes. However, one main drawback of it is the overhead on the control message signaling channels, In the paper, we propose an overlaying scheme on the existing mechanism that retains the desired properties of flooding, yet provides congestion control to the network. This is done by utilizing the wasted search messages to inform the network of the conditions of each path from one node to another. The overhead is to maintain a path table in each node. However, this overhead is not so critical. Also, this scheme can take advantages further by limiting the extent of message propagation through the network and by incorporating trunk reservation schemes additionally.