Research And Implementation Of Interconnection Between ATM/MPLS Network And IP/MPLS Network

MPLS is a new kind of technology which conducts data transmission and switch at the open communication network by using fixed label. MPLS technology have developed with high speed because of its high efficiency and unprecedented features since 1977.At present cell-switched MPLS became one of the hottest issue because of ATM network's high bandwidth, fast switch and assurance service quality.Cell-switched MPLS requires you to manage two fundamentally different types of equipment,one is cell-based LSR at the middle of MPLS network the other is frame-based LER at the edge of MPLS network and both of them connected by LC-ATM interface. This paper's main objective includes how design LC-ATM interface so as to convert core router into frame-based LER in MPLS network and generic requirements of interconnection between frame-based LER and cell-based LSR.Firstly this paper present a cell-switched MPLS network topology in which we discuss the label encapsulation, ATM-LSR features, cooperation between MPLS and ATM as "ships in the night "and solutions to interconnection between frame-based LER and cell-based LSR. Sencondly we also introduce both YH9300 core router's hardware and software architecture as frame-based LER and the updates of hardware and software is required to convert core router into frame-based LER.At last of this paper we present the design and implementation of LC-ATM interface which is applied to implement MPLS field interconnection.In terms of the process of AAL5 SAR sublayer, we present a multi-channel cell reassemble and schedule algorithm based on shared-memory structure. By theoretic analysis, we prove that the structure have fewer volume demand of the buffer and determinate reassemble delay bound. This method has applied to ATM interface design in core router successfully. Besides we deduct the CRC-32 implement circuit mathematically, which has the line-speed calculation capacity. So we can clear the two obstacles to implement LC-ATM interface.