Ligang Dong

Analysis and Implementation of an Open Programmable Router Based on Forwarding and Control Element Separation

A router architecture based upon ForCES (Forwarding and Control Element Separation), which is being standardized by IETF ForCES working group, gains its competitive advantage over traditional router architectures in flexibility, programmability, and cost-effectiveness. In this paper, design and implementation of a ForCES-based router (ForTER) is illustrated. Firstly, the implementation architecture of ForTER is discussed. Then, a layered software model, which well illustrates ForCES features, is proposed. Based on the model, design and implementation of Control Element (CE) and Forwarding Element (FE) in ForTER are introduced in detail. Moreover, security for ForTER is considered and an algorithm to prevent DoS attacks is presented. Lastly, experiments of ForTER are illustrated for routing and running routing protocols, network management, DoS attack prevention, etc. The experimental results show the feasibility of the ForTER design. Consequently, the ForTER implementation basically testifies the feasibility of ForCES architecture and some IETF ForCES specifications.

Design and Implementation of an Open Programmable Router Compliant to IETF ForCES Specifications

IETF ForCES (forwarding and control element separation) is defining specifications for interfaces and modular resources abstractions of network equipments. ForCES brings flexible, programmable, and cost-effective advantages over traditional architectures for network equipments. In this paper, the design and implementation of a ForCES-based router (ForTER) was illustrated. The framework of ForCES was introduced firstly. Then a layered model for the implementation of ForTER was presented. Next, the implementation details of control element (CE) and forwarding element (FE) of ForTER were introduced, which complied with the ForCES framework and related IETF ForCES specifications. Finally, results of experiments for routing and for SNMP support showed the feasibility of the system architecture of ForTER, which also fundamentally testified the feasibility of ForCES and related specifications that are being standardized by IETF ForCES working group.

Research and Design of the Pseudo-VRRP Based High Availability Mechanism in the ForCES Router

ForCES (Forwarding and Control Element Separation) architecture brought forward by IETF shows great advantages for network devices such as routers, wireless base stations, etc to be flexible, programmable, and cost-effective.This paper put forward a new high availability scheme for ForCES router. The framework of ForCES devices is firstly introduced. Then based on a revised VRRP protocol, a primary CE election mechanism is proposed and the kinds of ForCES information to be backuped are thoroughly analyzed. Next, system implementation issues are considered. Finally, a ForCES high availability router testbed is constructed, experiment results on it verifies the correctness, feasibility and efficiency of the proposed high availability scheme.

Definition and Implementation of Logical Function Blocks Compliant to ForCES Specification

IETF ForCES (forwarding and control element separation) is defining specifications for interfaces and modular resources abstractions in open programmable network equipments. According to drafts from ForCES, resources in the forwarding element are described in the form of logical function blocks (LFBs), each of which has a single specific function of processing packets. In this paper, we first design the taxonomy of LFBs. Second, we design basic LFB classes and associated types. Designed LFBs have been submitted to IETF ForCES working group. Thirdly, we systematically analyze various aspects in the implementation of LFBs. Finally, our experiments show LFBs can be successfully operated.

A Distributed Routing Algorithm Based on Architecture of ForCES

This paper presents a distributed routing algorithm based on architecture of Forwarding and Control Element Separation(ForCES). On this algorithm the calculating routing table divides into two parts, inner routing table between Forwarding Elements and outer routing table between routers. Then according to both routing tables the Control Element calculates the final routing table of each Forwarding Element. An independent routing server is used for the routing process, which decreases the amount of development work. This algorithm satisfies the distributed characteristic of ForCES router and reduces the amount of computation of Forwarding Element obviously. The algorithm has been applied at a prototype of ForCES router with satisfactory result.

A Network Controller Supported Open Reconfigurable Technology

In open reconfigurable architecture, the network devices realize the separation of the control plane and data plane. This paper study the control center of entire open reconfigurable network device: control element. It provides independent exclusive platform for control plane resources, which can enhance its scalability, control ability and efficiency significantly. The hierarchical structure of reconfigurable network and architecture of control element software are discussed. Then, core components of control element, which include protocol middleware and the development of user operating management system are introduced in details. Experiments of middleware software are illustrated for running routing protocols, network management, interface test etc. The experiment results show the feasibility of the control element design.

A Method of Bandwidth Allocation Mechanism in ForCES Transport Mapping Layer

This paper proposes a bandwidth allocation mechanism called rate and queue controlled dynamic probabilistic priority (RQ-DPP) based on ForCES transport mapping layer (ForCES TML). We apply this method to counter denial-of-service (DoS) attacks for ForCES router from redirect messages. The algorithm adjusts bandwidths between different messages based on messages kind, per-flow estimated arrival rate and buffer occupancy. By comparing with DRR, the simulation results show the effectiveness of the new bandwidth allocation mechanism.