Shigeo Matsuzawa

Internetworking based on cell switch router-architecture and protocol overview

This paper describes an internetworking architecture and related protocol overview based on routers that have asynchronous transfer mode (ATM) cell switching capability in addition to conventional Internet protocol (IP) packet forwarding. The proposed architecture can provide high-throughput and low-latency switched paths for individual application flows or a group of application flows while retaining current router-based internetworking architecture. The proposed router is able to establish the switched path based on the characteristics of flows, e.g., arrival of a data packet with specific upper layer protocols or arrival of more than a certain amount of data packets in a predetermined period, as well as by the reception of an IP-layer resource reservation request, such as resource reservation protocol (RSVP). One important feature that is provided by the proposed router is interoperability with the emerging ATM network platform specified by the ATM Forum and the telecommunications sector of the International Telecommunications Union (ITU-T). The proposed routers can be interconnected with each other over the point-to-point synchronous optical network link as well as over the ATM network platform, which provides permanent virtual channel, virtual path, or switched virtual channel (SVC) services. That enables network carriers to provide Internet/intranet services as well as others, such as telephony, ATM/time division multiplexing leased line, or native ATM SVC services.

Cell-switch router (CSR): label-switching router supporting standard ATM interfaces

Architecture overview of cell switch router (CSR), that is one of actual implementation using label switching paradigm, and the CSR prototype system supporting standard ATM interfaces are described. CSR can operate both with PVC (permanent virtual connection) and with SVC (switched virtual connection) as the VC for cut-through packet forwarding. CSR contains cell switch fabric and IP packet switch fabric to achieve high throughput IP forwarding. IP packets are forwarded either through a cut-through packet transmission, in which packet are forwarded without reassembling IP packet nor IP header processing, or through a conventional hop-by-hop IP packet forwarding. This paper describes and proposes the mechanism to forward the connectionless IP packet flows at the CSR. A CSR prototype system has developed. The CSR prototype system uses PVC and SVC connections to transfer the IP packets. With the CSR prototype system, we can make sure that CSR system could establish the cut-through packet transmission path between the adjacent node with acceptable establishment delay, that was less than few hundred second. The SVC connections for cut- through packet transmission are established on demand using ATM Forum UNI 3.0 or UNI 3.1.