OSPF Protocol Extension and Active Packet Delivery Scheme for IP Networks with Active Routers

능동 라우터를 가진 IP 네트워크를 위한 OSPF 프로토콜의 확장 및 능동 패킷 전달 방식

  • 안상현 (서울시립대학교 컴퓨터통계학과) ;
  • 김경춘 (서울시립대학교 컴퓨터통계학과) ;
  • 한민호 (한국전자통신연구원) ;
  • 나중찬 (한국전자통신연구원)
  • Published : 2003.02.01

Abstract

The existing active routing Protocols assume that the active network topology is static or pre-configured. However a dynamic mechanism to route an active Packet according to the network condition is required due to the dynamic characteristic of the active network. As active routing protocols, SLRP and TCOM500 PLAN project have been proposed, but since both of them are based on the assumption of the static topology we can not say that they are dynamic routing protocols in their entirety. Therefore, in this paper, we propose a new active network routing protocol, called AOSPF (Active Open Shortest Path First), which is compatible with the existing IP routing protocol. AOSPF is an extension of OSPF by adding a new LSA (Link State Advertisement) to allow the active network routing. The newly introduced LSA is used to specify whether the corresponding router is an active router or not. and one bit in the OPTION field of an LSA packet is used as the active router indication bit. This way of extending OSPF is similar to the scheme used in the extension of OSPF for multicast, i.e., MOSPF. In this paper, we will present the operation of AOSPF and the way how an active packet is forwarded based on the active network topology information constructed by AOSPF.

기존 능동 네트워크 기술에서의 능동 네트워크 라우팅은 정적인 토폴로지 구성을 가정하고 있다. 그러나 능동 네트워크도 기존 IP 네트워크와 마찬가지로 동적이기 때문에 네트워크의 상태에 따라 능동 패킷을 동적으로 라우팅해야 할 필요가 있다. 이와 관련해서 현재까지 PLAN 프로젝트에서 SLRP와 TCOM500 프로토콜들을 제시했으나, 두 프로토콜 모두 정적으로 구성되어 있는 토폴로지를 기반으로 하기 때문에 완전한 의미에서의 동적 라우팅 프로토콜이라고 볼 수 없다. 따라서 본 논문에서는 좀 더 동적이고 기존 프로토콜과의 호환성을 갖춘 능동 네트워크 라우팅 프로토콜인 AOSPF(Active Open Shortest Path First)를 제안한다. AOSPF는 능동 네트워크 라우팅을 위해 새로운 LSA(Link State Advertisement)를 추가함으로써 OSPF를 확장한 것으로 새로 정의된 LSA는 해당 라우터가 능동 라우터임을 명시하며 이를 위해 LSA 패킷내에 OPT10N 필드에서 사용되지 않는 비트중 하나를 능동 라우터 명시 비트로 사용한다. 이러한 OSPF의 확장 방법은 멀티캐스트를 위해 OSPF를 확장한 MOSPF와 유사하다. 본 논문에서는 AOSPF의 동작 과정과 AOSPF를 통해 구성된 능동 네트워크 토폴로지 정보를 기반으로 하는 능동 패킷의 전달 방법에 대해 기술한다.

Keywords

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