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小型企业的若干个分公司局域网之间需进行连接,DDN线路虽然通信质量很高,但其租金太高,对于小型企业来说,不可能每时每刻有恒定数据流量,因此DDN方式不太经济。用ISDN作局域网互联则很灵活方便,一条ISDN线路相当于两条64K专线的速率,可在各局域网之间建成高速、稳定的连接。同时,可通过ISDN将某局域网与Internet相连,使整个公司的每台PC可访问Internet。 企业可有用ISDN路由器(如贝尔SBT6062),用拨号方式接入,可以64K或128K的速率将两个局域网相连。该路由器同时具有IP包过滤和端口映射的功能,不仅保证网络的安全,也可为拨入的用户提供WWW、
DDN lines, although of high quality but with high rents, make it impossible for small businesses to have constant data traffic all the time, so the DDN approach is not economic. ISDN for LAN interconnection is very flexible and convenient, an ISDN line is equivalent to the rate of two 64K green, LAN can be built between the high-speed, stable connection. At the same time, a LAN can be connected to the Internet via ISDN, making each PC across the company accessible to the Internet. Enterprises can be useful ISDN routers (such as Bell SBT6062), with dial-up access, you can 64K or 128K speed two LAN connection. The router also has IP packet filtering and port mapping functions, not only to ensure network security, but also for dial-in users to provide WWW,