摘要:
An apparatus for providing passive bus communication in an ISDN without use of services of a central office uses an alternative error checking (CRC) technique for communication between devices on the passive bus. This alternate CRC is interpreted as an error at the central office so that local frames are discarded by the central office.
摘要:
An apparatus and method for transmitting X.25 communications over the D-channel of an ISDN link. This is achieved by terminal adapters connected between an X.25 terminal and an ISDN connection which contain converters to convert X.25 LAPB frames into LAPD frames and vice versa. The conversion process involves directly copying fields from the incoming LAPB frame into a LAPD frame with the minimum amount of verification. Essentially the only checking performed is to examine the number of octets in each field of the incoming frame to ensure that the conversion process itself does not fall down.
摘要:
A telephone apparatus includes a digital exchange unit and at least one digital telephone terminal connected to the digital exchange unit. The at least one digital telephone terminal generates monitoring signals and has multiple functions. All of the monitoring signals generated in the at least one digital telephone terminal are forwarded directly to the digital exchange unit. All of the functions of the at least one digital telephone terminal are controlled directly by the digital exchange unit through corresponding control signals.