Topic Last Modified: 2010-03-09
Deploying SIP trunking can be a big step toward simplifying your organization’s telecommunications and preparing for the latest real-time communications enhancements.
SIP Trunking in Communications Server 2010
The Communications Server 2010 SIP trunking capabilities enable the following scenarios:
- An enterprise user inside or outside the corporate firewall can
make a local or long-distance call specified by an E.164-compliant
number that is terminated on the PSTN as a service of the
corresponding service provider.
- Any PSTN subscriber can contact an enterprise user inside or
outside the corporate firewall by dialing a Direct Inward Dialing
number associated with that enterprise user.
The cost savings associated with SIP trunking can be substantial:
- Long distance calls typically cost much less through a SIP
- Expensive redundant networking can be eliminated if you adopt a
single, IP-based telephone and data network.
- Basic Rate Interface (BRI) and Primary Rate Interface (PRI)
fees can be eliminated if you connect a SIP trunk directly to your
ITSP at significantly lower cost. In legacy TDM trunking, service
providers charge for calls by the minute. The cost of SIP trunking
is based on bandwidth usage, which you can buy in smaller, more
SIP Trunking as an Alternative to an IP-PSTN Gateway or IP-PBX
Because SIP trunks connect directly to your service provider without traversing the PSTN, you can eliminate your IP-PSTN gateways and their attendant cost and complexity. Some ITSPs offer to host a PBX for you if you choose. This can lead to substantial cost savings through reduced maintenance and administration.
If you have an IP-PBX that is nearing end of life, rather than invest in an upgrade, consider replacing it with a SIP trunk at a much lower cost.
Expanded VoIP Services
Voice features are often the primary motivation for deploying SIP trunking, but voice support alone is just the first step. With SIP trunking, you can extend VoIP capabilities and enable Communications Server 2010 to deliver a richer set of services than you can get with legacy technology. For example, the same SIP trunk that delivers your telephone service and other VoIP communications services can now provide:
- Enhanced presence detection for devices that are not running
Office Communicator provides better integration with mobile phones,
allowing you to see when a user is on a cell phone call.
- E-911 emergency calling enables the authorities who answer 911
calls to determine the caller’s location based on their telephone
- GPS locations can be integrated with your Location Information
server to track mobile user location.