Overview of PBX

The voice feature of the AR router provides the IP-PBX service based on the RFC standard. The signaling is transmitted using SIP, and the voice media is transmitted using RTP. In this version, SIP TLS and SRTP are not supported; therefore, VoIP signaling and voice media in the IP-PBX service are transmitted in plaintext over the network.

The voice feature of the AR router provides PBX services, including call barring, password-based calling, secretary service, and deactivation of all services. These services involve transmission of service passwords in plaintext using SIP between VoIP terminals and the AR router. Therefore, ensure that these services are used in trusted networks. Note that the service passwords here are bound to specific VoIP terminals.

The voice feature of the AR router provides voice mailbox and outgoing call barring services. These two services involve transmission of service passwords in plaintext using RTP between VoIP terminals and the AR router. Therefore, ensure that these services are used in trusted networks. Note that the service passwords here are bound to specific VoIP terminals.

The voice feature of the AR router provides the voice conference services. This service involves transmission of conference access passwords in plaintext using RTP between VoIP terminals and the AR router. Therefore, ensure that these services are used in trusted networks. Note that the conference access passwords here are valid within the specific conference time.

If the above-mentioned services are used in non-trusted networks, encrypted IPSec channels can be set up between the AR router on the terminal side and the AR router that provides such services to ensure password transmission security. For details, see CLI-based Configuration > Configuration Guide - VPN.

Figure 2-1 Encrypting transmission channels using VPN

Encrypted channels are set up using IPSec between the AR router deployed in the terminal area and the AR router that provides voice PBX services in the service area. Then, passwords involved in the above-mentioned services are transmitted over the encrypted IPSec channels.