Topic Last Modified: 2010-11-05
An enterprise-grade VoIP solution must provide for calls to and from the public switched telephone network (PSTN) without any decline in Quality of Service (QoS). Users placing and receiving calls should not be aware of the underlying technology: from the user's perspective, a call between the Enterprise Voice infrastructure and the PSTN should seem like just another phone call.
Microsoft Lync Server 2010 provides reliable, scalable PSTN connectivity by using the following options:
- SIP trunking to an Internet telephony service provider (ITSP)
- Direct SIP connections to a PSTN gateway
- Direct SIP connections to a PBX
Depending on its size, geographic coverage, and existing voice infrastructure, a given enterprise may use one, two, or even all three of these options at various locations.