• Journal of Internet Computing and Services
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• v.2 no.2
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• pp.23-36
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• 2001

To support real-time multicast, the existing DS network may use the EF PHB for transmission, However, because of the dynamic characteristics of the multicast flow and the features of the EF PHB. it is very difficult to make a provision of resources or to manage the network when EF multicast flows increase, Also, the existing LBE PHB can not guarantee the transmission delay bounds required for the real-time multicast traffic, In this paper. a new concept of PHB. namely, low-delay multicast PHB, that may guarantee approximately the per-hop delay is proposed, For the low-delay multicast PHB, router architectures are devised, The queue management algorithm on a low-delay multicast queue and a scheduling method are also devised. This new architecture of the LDM AF class is simple to be implemented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.23-30
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• 2009

This paper addresses the design of trTCM (Two Rate Three Color Marker) described in RFC2698. It has proposed for trTCM to be used in Differentiated Service network that provides AF PHB (Assured Forwarding Per Hop Behavior). trTCM is the marker with the metering function, and consists of the token updating function and the marking function. The token updating function uses the dual token bucket. The marking function compares the token values with the length of input packet and then marks the result into IP QoS field (ToS field). In this paper, we design trTCM function and then addresses the scheme to implement it using FPGA technology.

• Journal of KIISE:Information Networking
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• v.29 no.6
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• pp.706-711
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• 2002

In this paper, we implement a diffserv-capable router on the linux system and evaluate its performance. The router supports the packet marking for the input finks that is different from the previous implementation. The edge diffserv-capable router can guarantee the performance of each class, even in a congested condition. We compare the performance of the diffserv-capable router with that of the normal router in terms of PDBs (per domain behaviors), which are defined with traffic conditioning rules and PHBs (per hop behaviors).

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.53-56
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• 2002

In this paper, we study the network structure that can guarantee the end-to-end quality of service in the Explicit multicast network. In order to guarantee the end-to-end quality of service, we adopt the end-to-end measurement based admission control (EMBAC) scheme. For the effective measurement of the network state and minimum influence on the current data traffic, the queue structure, which the drop precedence in assured forwarding (AF) Per hop behavior (PHB) of the differentiated service (Diffserv) is applied to, is proposed. Through a simulation, we show that EMBAC can make tile controlled load service in tile AF PHB applied Xcast network, and the qualify of the admitted traffic is guaranteed. In addition, the performance of the EMBAC is changing according to the selling parameter of AF PHB.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.303-308
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• 2016

Recently, as the rapid development of network technology and the increase of services required high bandwidth such as multimedia service, the network traffic dramatically increases. This massive increase of network traffic causes some problems such as the degradation of QoS and the lack of network resources and, to solve these problems, various research to guarantee QoS have been performing. Currently, The most representative method to guarantee the QoS is the DiffServ(: Differentiated Service). The DiffServ defines the AF(: Assured Forwarding) PHB(: Per Hop Behavior) and statistically ensures the throughput over the certain level of data rate. However, the TCP congestion control method that make up the majority of the Internet traffic is not fundamentally suitable to the DiffServ that guarantees the throughput without managing the individual flow. Therefore, in this paper, we present this mismatch through the simulation as an example and propose the solution by controlling the TCP of the terminal in the network. The proposed scheme utilizes the information of the reception window size included in the ACK frame and does not require any modification of the TCP algorithms currently in use.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.127-133
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• 2011

This study proposed the PHB mapping model for combining services with DiffServ in the MPLS network capable of high-speed switching, and the effective differential bandwidth service model in the MPLS network on the basis of the proposed mapping model. The result of simulation on the service model using PRI showed that the transmission rate was achieved as much as the assigned bandwidth regardless of the increase of traffic as far as the EF PHB did not exceed the assigned bandwidth at the peak rate when the overall traffic increased.

• Journal of information and communication convergence engineering
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• v.1 no.3
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• pp.123-128
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• 2003

This paper has addressed the implementation of the single rate Rate Adaptive Shaper(srRAS) described in RFC2963. This shaper has been proposed to use at the ingress of differentiated services networks providing Assured Forwarding Per Hop Behavior (AFPHB). srRAS is typically used in conjunction with single rate Three Color Marker(srTCM) described in RFC2697. srRAS itself is the tail-drop FIFO that is drained at a variable rate, and srTCM is the marker with metering function. G-srRAS is the same as srRAS except that RAS receives the green token state information from the downstream srTCM to avoid delaying a packet in RAS although there are sufficient tokens available to color the packet green. In this paper, we have addressed the algorithm and the architecture of srRAS, and the scheme to implement srRAS using VHDL(Very high-speed integrated circuit Hardware Description Language) and its related tools.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.141-148
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• 2005

This paper addresses the design of srTCM (single rate Three Color Marker) described in RFC2697. It has proposed for srTCM to be used at the ingress of Differentiated Service network that provides AF PHB (Assured Forwarding Per Hop Behavior). srTCM is the marker with the metering function, and consists of the token updating function and the marking function. The token updating function uses the dual token bucket. The marking function compares the token values with the length of input packet, and then marks the result into IP QoS field (ToS field). This paper designs srTCM function and then implements it in one chip using VHDL and FPGA technology.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.235-245
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• 2005

In this paper, a simplified QoS model of MPLS-based backbone network. Conventional scheme proposed by IETF(IETF schem) is to embed a DiffServ model in MPLS network. However, this approach results in overall upgrade of MPLS system and so it is difficult to deploy this approach. Our proposed model, however, uses a Vidual Link which is a set of Label Switched Path(LSP) connected from an Ingress Label Edge Router(LER) to an Egress LER. In this model, Per-Hop-Behavior(PHB) is implemented only at each LSP in ingress LER and Core Label Switch Routers(LSRs) just guarantee each LSP's bandwidth, not service. This bandwidth guarantee service is fully provided by legacy MPLS model. Also we propose flow allocation mechanism and the flow distribution among LSPs of the virtual link by the flow according to the network status. To evaluate the simplified approach, the characteristics of the approach are compared logically with these of IETF's one through simulations.

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.70-78
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• 2006

This paper has addressed the scheme to design single rate Rate Adaptive Shaper (srRAS) proposed in RFC2963. srRAS is the shaper used in conjugation with downstream single rate Three Color Marker (srTCM) described in RFC269. it is tail-drop First Input First Out (FIFO) queue that is drained at a variable rate. srTCM meters IP packet streams from srRAS and marks its packets to be either green, yellow, or red. This shaper has been proposed to use at the ingress of differentiated services networks providing AF PHB. And then srRAS can reduce the burstiness of the upstream traffic of srTCM. This paper addresses algorithm, architecture of srRAS, and the scheme to implement srRAS using Field-Programmable Gate Arrays (FPGA) and the related technology.