【摘要】 本文比较了利用窄带ISDN和帧中继技术与利用城域网(Metropolitan Area Network——MAN)来实现过渡的两种方案,指出利用MAN过渡到B-ISDN具有更多的优越性。MAN是为适应局域网(LAN)互连和高速数据通信而发展起来的,网距通常可达30～50km,由于它在信元格式和传输方式上与B-ISDN的兼容性,使得它成为从现有网络向B-ISDN过渡的最佳中介城域网技术。更多还原

【Abstract】 From the comparison between the two transition plans-from N-ISDN and Frame Relay (FR) tq B-ISDN and from Metropolitan Area Network (MAN) to B-ISDN,we conclude that the latter is a better choice. MAN originated as an extension of Local Area Networks (LAN) to cover wider areas and enable high-speed data communications. MAN’s compatibility with B-ISDN in the aspects of cell structure and transfer mode makes it the forerunner of B-ISDN.更多还原