A High-Speed Tandem-Crosspoint ATM Switch Architecture with Input and Output Buffers

Eiji OKI  Naoaki YAMANAKA  

IEICE TRANSACTIONS on Communications   Vol.E81-B    No.2    pp.215-223
Publication Date: 1998/02/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on ATM Switching Systems for future B-ISDN)
Category: ATM switching architecture
ATM,  switch,  high-speed,  crosspoint,  buffer,  

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This paper proposes a high-speed input and output buffering ATM switch, named Tandem-Crosspoint (TDXP) switch. The TDXP switch consists of multiple crossbar switch planes. These switch planes are connected in tandem at every crosspoint. Even if a cell can not be transmitted to an output port on the first plane, it has a chance to be transmitted on the next plane. Cell transmission is executed on each switch plane in a pipeline manner. Therefore, more than one cell can be transmitted to the same output port within one cell time slot, although the internal line speed of each switch is equal to the input /output line speed. The TDXP switch architecture has several advantages in implementation. First, the TDXP switch does not increase the internal line speed in eliminating Head-Of-Line (HOL) blocking. Second, since the TDXP switch employs a simple cell reading algorithm at the input buffer in order to retain the cell sequence, the TDXP switch does not require to rebuild the cell sequences at output buffers using time stamps, as is required by a parallel switch. These merits make implementing the high-speed ATM switch easy. Numerical results show that the TDXP switch can eliminate the HOL blocking effectively and achieve high throughput both for unicasting and multicasting traffic. This switch architecture is expected to enable the development of high-speed ATM switching systems that can realize over 1 Tb/s throughput in a cost-effective way.