Port 5031
AVM CAPI-over-TCP
AVM CAPI-over-TCP enables ISDN signaling data to be transmitted over Ethernet networks, effectively encapsulating ISDN protocols within TCP/IP for remote access or integration. This facilitates the bridging of traditional ISDN communication with modern IP infrastructure, often serving AVM's Fritz!Box devices and similar hardware..
Technical Details
AVM CAPI-over-TCP facilitates the tunneling of ISDN signaling data across IP-based networks. It encapsulates the CAPI (Common ISDN Application Programming Interface) commands and responses within TCP or UDP packets, enabling ISDN services to function over Ethernet rather than physical ISDN lines. This is especially beneficial in environments where legacy ISDN devices need integration with IP infrastructures.
The protocol is commonly used by AVM devices such as Fritz!Box routers, providing an interface for telephony services across the network. By carrying CAPI messages over TCP/IP, the system can maintain compatibility with ISDN software and applications even if native ISDN hardware is unavailable onsite.
Operationally, this tunnel allows remote access to ISDN lines or virtualized ISDN services. It can be utilized for call signaling, D-channel messaging, and facsimile data, maintaining the full feature set of traditional ISDN over an Ethernet transport.