Study on Implementation of an MPLS Switch Supporting Diffserv with VOQ-PHB

Recently, the growth of Internet and a variety of multimedia services through Internet increasingly demands high-speed packet transmission, the new routing function, and QoS guarantee on conventional routers. Thus, a new switching mechanical called the MPLS(Multi-Protocol Label Switching), was proposed by IETF(Internet Engineering Task Force) as a solution to meet these demands. In addition the deployment of MPLS network supporting Differentiated Services is required. In this paper, we propose the architecture of the MPLS switch supporting Differentiated Services in the MPLS-based network. The traffic conditioner consists of a classifier, a meter, and a marker. The VOQ-PHB module, which combines input Queue with each PHB queue, is implemented to utilize the resources efficiently. It employs the Priority-iSLIP scheduling algorithm to support high-speed switching. We have designed and verified the new and fast hardware architecture of VOQ-PHB and the traffic conditioner for QoS and high-speed switching using NS-2 simulator. In addition, the proposed architecture is modeled in VHDL, synthesized and verified by the VSS analyzer from SYNOPSYS. Finally, to justify the validity of the hardware architecture, the proposed architecture is placed and routed using Apollo tool.

Diffserv 지원 VOQ-PHB방식의 MPLS 스위치의 구현에 관한 연구

인터넷 트래픽의 급격한 증가에 따라, 새로운 멀티미디어 서비스의 요구를 수용하기 위해서 MPLS가 제안되었으며, MPLS는 QoS 를 보장하는 Differentiated Service를 제공하는 방향으로 진화되고 있다. 본 논문에서는 Diffserv를 지원하며, 고속의 스위칭이 가능한 MPLS 스위치의 구조를 제안한다. 트래픽 제어기는 분류, 측정, 기록 둥의 기능을 수행하도록 구성되었다. 스위치는 입력 큐잉 방식으로 QoS를 보장하도록 VOQ와 PHB별 큐를 확장한 방식이며, 이의 스케줄링 알고리즘으로는 Priority-iSLIP 알고리즘을 사용하였다. 제안한 구조는 NS-2 시뮬레이터로 모델링하여 검증하였고, VHDL을 이용하여 모델링하여 합성한 후, SYNOPSYS사의 VSS analyzer를 이용하여 그 타당성을 검증하였다. 또한 Apollo tool을 이용하여 layout을 수행하였다.