Goal

This scenario is targeting the setting up of basic voice services for an institution. We are proposing a solution where the IP PBX is complementary to the PBX of the institution.
The features that we will be explored are:

• authenticated login
• user provisioning
• gateway to the PSTN
• gateway between SIP and ?.323
• local dial plan
• encryption (endpoint-to-endpoint)
• codec support
• handling of both numeric and alpha-numeric addresses
• accounting
• qos
• availability checks

Applicability

• SIP interface with SIP proxy (OpenSER)
• H.323 interface with H.323 gatekeeper (GnuGk)
• SIP to H.323 gateway (Asterisk)
• Radius authentication (FreeRadius, Radiator)
• LDAP identity management infrastructure (OpenLDAP)
• accounting (MySQL)

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guide helps you setup a simple, mature and flexible open source SIP server. OpenSER can be used on systems with limitted resources as well as on carrier grade servers, scaling to up to thousands call setups per second.

Applicability

Prerequisites (OS, dependencies on other software)

• a PBX (to interface to local institution phones)
• a gateway (to connect from the IP world to the PBX)
• authentication infrastructure (Radius or LDAP)

Configuration (OS agnostic)

OpenSER - The SIP interface

Sample config for a typical OpenSER setup with:

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