The exemplary fallback module 316 is configured to monitor call quality and handle an auto-fallback process. The auto-fallback process, may occur when the call management system 112 cannot reach a receiving call management system 112 (PBX or router) via the IP network 106. Furthermore, auto-fallback may occur when for example, the fallback module 316 determines that quality of the free trixNet call is, or will be, poor (e.g., by using any qualitative means of measurement such as round-trip ping time, jitter, sine-wave audio echo analysis, live MOS scoring). As such, the free trixNet call is able to automatically “fall back” to a normal trunking that the calling call management system 112 uses (e.g., VoIP, analog, or TDM). This “fall-back” occurs in milliseconds or seconds and may be transparent to the user. Advantageously, the user does not have to specify that they want to make a free call. The call management system 112 tries for the free call, then goes paid if it cannot or determines it does not want to (e.g., quality is poor) go free.

The optional local relational database 318 stores telephone numbers of trixNet members in a relational database. In some embodiments, these telephone numbers may be mapped to a dynamic address associated with the dynamic address engine 310. If dynamic addresses are used (e.g., those used by cable modem or DSL services), the address associated with that telephone number is automatically updated. In other embodiments, the local relationship database 318 may comprise a copy of the relational database of the data center system 104, thus enabling peer-to-peer communications without access to the data center system 104.