OLI-based billing

Vendors that provide toll-free numbers to service providers can charge a different price for calls that originate from a payphone or a paystation.

With PortaSwitch, service providers can take call origination into account when charging their customers and calculating calls’ cost on the incoming connections (Calls from Vendor via SIP and Calls from Vendor via PSTN).

Call origination type is determined based on the Origination Line Information (OLI) parameter. The OLI is transmitted over PSTN networks as signals. There is no common standard for carrying OLI over SIP, but one popular way is to use the isup-oli SIP URI parameter and include it in the SIP INVITE message, notably in the From header.

For example, for calls made from a payphone, the From header may look like the following:

From: "18005551155" <sip:18005551155@111.11.11.11:5060;isup-oli=27>;tag=gK037dd60b

PortaSIP extracts this value and assigns it to the Originating-Line-Info RADIUS attribute which will be then passed to PortaBilling:

NAS-IP-Address = '111.11.11.11'
‎User-Name = '18005551155'

…..

Originating-Line-Info = '27'

…

Using this value, the billing engine seeks a rating entry that can match it, and if one is found, it both charges for the call and calculates the call cost accordingly.

OLI digit pairs and their descriptions are represented in the following table: