SIP Trunking Frequently Asked Questions
What is SIP?
Session Initiation Protocol (SIP) is the common signaling standard for real-time communications including Voice over Internet Protocol (VoIP). SIP is an open-standard which allows carrier voice equipment to interoperate seamlessly with customer premise equipment (CPE). The logical voice channel established between them is referred to as a SIP Trunk; a virtual phone line that utilizes a Broadband connection for access.
What is a SIP Trunk?
SIP Trunks are virtual circuits delivered over an Internet Access line.
What is SIP Trunking Service?
SIP Trunking is a service that allows businesses that have a PBX installed to use Voice-over-IP (VoIP) outside the network by using an Internet connection.
What equipment is Required for SIP Trunking?
SIP Trunks can work with a SIP-ready PBX. SIP Trunks can work with traditional analog or key systems with an IAD (Integrated Access Device). The SIP Trunk service provider will need to interoperate with the underlying equipment manufacturer.
How does SIP Trunking Compare to PRI's?
Simultaneous Calls with PRI:
Typically, businesses utilize 1/3 of their phone lines for their employees. For example, a company only requires 33 shared phone lines for 99 employees.
How Many Channels/Lines for PRI?
A single PRI consists of 23 channels. This means a business that needs 29 lines must buy 2 PRIs. In this case, the business is purchasing more lines than are required. With SIP, purchases can be made in increments of 1 rather than 23.
On Demand Scalability:
When your office grows, new phone lines need to be added. With PRIs, it may take 30 days to provision additional lines. With SIP, lines can be added on demand with remote enabling.
Remote Locations:
Remote extensions may require multiple service providers with PRI's. Utilizing SIP Trunking, remote extensions will use the same carrier, the same network, all on a global basis.
Bandwidth Requirements:
The majority of business have approximately 35% excess Internet access capacity. The excess bandwidth may be utilized for a company's voice traffic with SIP trunking. To help manage Bandwidth, it can be dynamically allocated between voice and data with SIP Trunks.
Network Efficiency:
SIP Trunking allows for dynamically scalable internet and voice bandwidth. Conversely, PRI's are fixed, resulting in underutilized bandwidth.
A Single Carrier Solution:
Businesses with multiple locations often use multiple carriers to connect their voice and data networks. With SIP Trunking Solutions, you will use a single carrier for your combined network. Receive on combined bill for Internet access, and voice.
What are the Cost Benefits of Using SIP compared to PRI?
The primary SIP Trunking benefit over PRI is cost savings. SIP trunks typically cost under $25 per trunk for unlimited inbound and local calling along with a long distance rate that can be under 2 cents per call. When coupled with line oversubscription (e.g. a 30 person company purchasing just as many SIP trunks as they anticipate having concurrent calls....typically 8 to 10) SIP Trunks are a very cost effective way for a business to save money.
What are the cost Benefits of using SIP Compared to Analog Service?
SIP Trunks are cheaper than analog circuits while maintaining business quality voice service. SIP Trunks cost less than $25 per trunk, versus approximately $40 per analog circuit. In addition, long distance termination charges associated with SIP Trunks are much cheaper than traditional analog or TDM rates.
When should a business consider migrating to SIP Trunking?
A business should look into SIP Trunking when they decide that they require a premise-based system, or IP-PBX. An IP-PBX offers similar features to hosted solutions, but is often less expensive.
Is additional Internet Bandwidth required for SIP Trunking?
Depending on the number of SIP Trunks purchased, and the current excess Internet bandwidth, additional Internet Access should be considered. When a SIP Trunk is not being used, the bandwidth otherwise assigned to a SIP Trunk is dynamically allocated for use in other applications, such as e-mail and web surfing.
