To connect LANs, ISLNs and telephony networks into an organic network by using PRE-ISDN as a backbone, the overall interworking for LAN, telephone two services between LAN, public two type networks can be achieved with wide useful future while keeping cost low.
以PRE-ISDN为远程骨干把LAN、ISLN、电话网互连成一体网络,可以实现LNN、电话两种业务在公用网和局域网之间的全面互通,具有广阔的应用前景,而成本却十分低廉。