User guide

Chapter 5 — Phonebook Configuration
Multi-Tech Systems, Inc. 67
The Alternate Routing function facilitates PSTN Failover protection, that is, it allows you to re-route VOIP calls
automatically over the PSTN if the VOIP system fails. The MultiVOIP can be programmed to respond to excessive
delays in the transmission of voice packets, which the MultiVOIP interprets as a failure of the IP network. Upon
detecting an excessive delay in transmission of voice packets (overly high “latency” in the network) the
MultiVOIP diverts the call to another IP address, which itself is connected to the PSTN (for example, via an FXO
port on the self-same MultiVOIP could be connected to the PSTN).
PSTN Failover Feature. The MultiVOIP can be programmed to divert calls to the PSTN temporarily in case the IP
network fails. See Figure 5-4 below for example.
IP
NETWORK
FXS
FXO
VOIP
VOIP
PBX
PSTN Line
1. Call originates.
2. IP network fails.
3. Call diverts to
Alt IP address in voip
accessing PSTN line.
4. Call completed
via PSTN.
PSTN failover
Inbound Phone Book/List Entries
The “Details” and “Registration Options” sections will display information based on the setup and protocols
chosen. The “Subscription Options” area is used in conjunction with a Voice Mail Server.
Inbound phonebook entries