Integrated Services Digital Network (ISDN) is an international standard for digital telephone networks and a typical circuit switching network system.In the proposal of ITU, ISDN is a kind of communication network developed on the basis of digital telephone network IDN, ISDN can support various services, including telephone service and non-telephone service.
Protection of the circuit
SDN CO and CPE equipment must be protected from possible power crosstalk and lightning faults at the moment of ingress from external transmission lines. Circuit protection based on regional requirements specifications is recommended.
ADSL
Introduction to ADSL
Asymmetric Digital Subscriber Line (ADSL, Asymmetric Digital Subscriber Line) is the most popular type of Digital Subscriber Line service.The key concept of ADSL, which is also the key to the simultaneous transmission of digital signals and analog signals on the telephone line, is that its upstream and downstream bands are asymmetrical.
Resettable protection solution
ADSL modems and splitters must be protected against external and internal faults. Recommend resettable protection solutions based on regional needs.
HDSL
HDSL equipment must be protected against possible power crosstalk and lightning faults at the moment of incoming external transmission lines.Circuit protection based on regional requirements specifications is recommended.
MDF
Circuit protection is recommended in MDF/primary protection modules to protect against the risk of power crosstalk and lightning faults at telecom central offices and subscriber terminals.