What is a SIP Trunk
A SIP Trunk is a virtual telephone service connection between an organization’s IP PBX and an Internet Telephone Service Provider (ITSP). It allows you to establish telephony service to your IP PBX beyond your organization’s infrastructure without requiring a physical connection or IP-to-PSTN Gateway on the premises. ITSPs (Internet Telephone Service Providers) provide SIP Trunks, which are delivered at substantial savings so your investment in IP PBX & SIP Trunk can give a quick and substantial return on investment while also improving your service delivery and profitability.
SIP (Session Initiated Protocol) is used to create and control the communications sessions that are the basis of VoIP Telephony. SIP is also used for instant messaging, presence updates, multimedia, conferencing, and other real-time services that can traverse a SIP Trunk.
The term "Trunk" in SIP Trunking derives from circuit-switched telecommunications. It refers to a dedicated physical line that connects switching equipment. A SIP Trunk is similar to its circuit-switched predecessor in that it is a connection between telecommunications systems, but it is different because the connection it describes is virtual and not physical. This connection can be made over a network that is used only for SIP Trunking, over a dedicated network that carries SIP Trunking with other IP traffic, or over the Internet on a virtual private network (VPN).
A SIP Trunk can connect your organization and branches to an ITSP through either an IP-PBX owned by your organization or hosted by the ITSP.
What Are The Benefits of SIP Trunk?
Deploying a SIP Trunk is a big step towards simplifying your organization’s telecommunication needs and preparing for the latest real-time communications enhancements, but the biggest motivation for most organizations is immediate and substantial cost savings.
Installation & Configuration
Unlike traditional E1/T1 Trunks that require a service provider to terminate the Trunk at client site, SIP Trunks require no physical installation at the client site, there is no cable or civil works. SIP Trunk is revolutionary because the connection relies on new or existing Internet Service and Telephone Trunks can now be provided within minutes of a client requesting them. No more waiting for PSTN Providers to get site and digging approval before they can lay cables to your location.
Service & Number Mobility
With E1/T1 Trunks, when a client moved its business from one location to another, it was difficult to retain the same service and telephone numbers. The obvious reasons include the location of the Trunk Provider, civil works required to move the Trunk to the new site and many other complications that arise. However, with SIP Trunks, this is no longer a problem as SIP service is virtual and the client doesn't need any new configuration. Whether the IP PBX infrastructure is on-premise or hosted, service is immediately resumed once the client powers on their IP PBX.
Scalability & Cost
With E1/T1 Trunks, clients have to acquire and scale telephone lines in multiples of 30, even when they did not need up to 30 lines. This usually comes at a cost far above what the business intends to spend for telephony service. For enterprises, this may be affordable, but it is definitely not a cost that small and medium businesses can afford. With SIP Trunks, small, medium and large enterprises can acquire telephone lines from as little as 1 to as many as they require without buying in bulk or multiples ... even at better prices. They can also scale up and down as their needs change.
Save on Long Distance Cost
SIP Trunks provide you very cheap call rates and comfort while making or receiving long distance calls as long distance service typically costs significantly less with a SIP Trunk connection.
Trunk services provide you local presence in international locations with the availability of international phone numbers (DID) of a wide range of countries.
Eliminate IP-to-PSTN Gateways (or even your entire PBX)
Because SIP Trunks connect directly to your ITSP without traversing the Publicly Switched Telephone Network (PSTN), you can get rid of IP-to-PSTN gateways and their attendant costs and complexity and alternatively host your entire IP PBX with an ITSP thereby handing over both the hardware and administration. This provides substantial cost savings and reduces complexity as your business grows into an enterprise.
Eliminate a Redundant Network, BRI & PRI Subscription
Deploying SIP Trunk is a logical step towards the goal of having a single, IP-based network, rather than redundant telephone and data networks. Eliminate BRI and PRI Subscription Fees: With a SIP Trunk connected directly to an Internet Telephone Service Provider, you can dispense with costly BRIs and PRIs, replacing them with service that costs significantly less.
Extend the Capabilities of Unified Communications
With a SIP Trunk in place, you can extend existing capabilities with additional services such as Chat, Conference Calls, File Sharing.
SIP Trunks are definitely the new solution for Enterprise Telephony and while being able to provide enterprise-level telephony, SIP Trunks are affordable even for small and medium businesses.