Protocol Proxy for OSPF Emulation

This paper proposes a protocol proxy scheme that can emulate the open shortest path first (OSPF) protocol in an effective and flexible manner. It is implemented in our developed network emulator, which is used to test network controllers for IP optical network management. In the protocol scheme, OSPF protocol emulation is achieved by combining an OSPF protocol proxy (introduced here) and an OSPF peer state manager based on existing OSPF protocol software. The protocol proxy produces OSPF packets holding link state advertisements with customized extensions including MPLS and GMPLS, while the OSPF peer state manager implements neighbor establishment via the proxy. The protocol proxy has two main functions: rewrite OSPF packets originated by the OSPF peer state manager and generate OSPF packets to inform the updated topology to the network controller. To implement the customized OSPF extensions, only the protocol proxy software need be modified; the existing OSPF software for the OPSF peer state manager is not touched. This makes the implementation of the OSPF emulation easy and flexible. Furthermore, the protocol proxy obtains the network topology information from the resource simulator, which is managed in a centralized manner. This reduces the amount of processing resources required and is scalable in terms of network size. We develop a prototype of the network emulator including OSPF protocol emulation with the protocol proxy scheme. The effectiveness of the protocol proxy scheme is confirmed by an experiment on 40 nodes.