16.3. Core call routing switch
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16.3. Core call routing switch

The design allows the FB6502 to perform the grunt of a large scale voice network leaving external devices (e.g. linux boxes) to make decisions and log calls, interacting via RADIUS messages. The FB6502 can work with pools of RADIUS servers for fallback and load management.

16.3.1. Call control

The basic concept is that the FireBrick handles the SIP messages and audio RTP, but uses RADIUS to decide what to do. Appendix F defines the RADIUS messages used and the responses necessary to use the FireBrick as a core VoIP switch.

16.3.2. Bulk registration client

The FireBrick can be used to perform registrations as a SIP client, sending REGISTER messages and maintaining the registration with remote servers.

To do this you define a carrier-url in the VoIP settings. The FireBrick does a simple http GET on this periodically (set carrier-update to control frequency). The response is expected to be plain text containing space or comma separated values:-

  • Carrier name (this is the key to identify each carrier)
  • VoIP server hostname or IP address
  • Authentication username (blank if not used)
  • Authentication password (blank if not used)
  • Optional source IP to use for outgoing messages to this carrier

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16.2. Registration and Proxies Home 16.4. Network Address Translation