User guide

Chapter 5 – Configuring the Phone Book
92 MultiVOIP® Voice/Fax over IP Gateways
Configuring Alternate Routing
Alternate routing provides an alternate path for calls if the primary IP network cannot carry the traffic.
Sometimes during failure, call traffic is temporarily diverted into the PSTN. However, you also use alternate
routing to divert traffic to a redundant (backup) unit in case one VOIP unit fails.
Alternate routing facilitates PSTN Failover protection. It allows you to re-route VOIP calls automatically over the
PSTN if the VOIP system fails. You can program the MultiVOIP 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 is connected to the PSTN).
To set up alternate routing:
1. Click Advanced. The Alternate Routing window opens.
2. Specify the IP address of the alternate route for each destination pattern entry in the Outbound Phonebook.
The following table describes alternate routing fields.
Alternate Routing Field Definitions
Field Name
Values
Description
Alternate IP
Address
n.n.n.n
Alternate destination for outbound data traffic if excessive delay in data transmission.
Round Trip
Delay
Default is 300
milliseconds
The Round Trip Delay determines when a data pathway is considered blocked. When the
delay exceeds the threshold specified here, the data stream is diverted to the alternate
destination specified as the Alternate IP Address.