SIP Trunking uses Session Initiation Protocol (SIP) to establish voice communication between an Internet Telephony Service Provider (ITSP) like Broadvox and a company’s IP-PBX. ITSPs provide VoIP communication over the Internet. They are different from ISPs (Internet Service Providers) in that voice communication is enabled with SIP, but with ISPs, only the Internet connection is provided. Broadvox is a business VoIP provider with an expertly engineered IP network that offers greater reliability, features and functionality than the public Internet. Businesses are able to migrate to IP Communications from traditional TDM gradually, using their legacy CPE with a gateway device or all at once with an IP PBX. This flexibility allows communication between any device that is IP enabled, including SIP phones, smart phones, PDAs and computers.

Historically, voice signals traveled over physical wires but SIP Trunking makes a logical connection from one point to another through the Internet, making it possible to treat voice communication as just another application and deliver it as packets of data.

For enterprises wanting to make full use of their installed IP-PBX's and not only communicate over IP within the enterprise, but also outside the enterprise a SIP trunk provided by an Internet Telephony Service Provider to connect to the traditional PSTN network is the solution. Unlike in traditional telephony, where bundles of physical wires were once delivered from the service provider to a business, a SIP trunk allows a company to replace these traditional fixed PSTN lines with PSTN connectivity via a SIP trunking service provider on the Internet.

SIP trunks can offer significant cost-savings for enterprises, eliminating the need for local PSTN gateways, costly ISDN BRI's (Basic Rate Interfaces) or PRI's (Primary Rate Interfaces).

The primary benefit of SIP Trunking is the reduction in communications cost; typically 40 - 70% below what legacy Telcos offer, but the major features it provides are those that enhance functionality and scalability and resolve issues related to large-scale enterprise deployments. Some of the features of the SIP Trunking business VoIP product line include:

• Unlimited local and long distance calling in the United States (except Alaska), Puerto Rico, US Virgin Islands and Canada
• Discounted international calling
• One BTN (Billing Telephone Number) with E911
• G.711 and G.729A codecs
• PSTN origination/termination
• Additional DID's can be ordered individually or in any amount
• 24/7 Network Operations Center with expert engineering support
• Unlimited concurrent call sessions (limited only by available bandwidth)
• Operates with legacy CPE through VoIP gateways to deliver IP Communications benefits

Additional options are available, such as:

• Local Number Portability (LNP)
• Enhanced 911
• Calling Name (CNAM)
• Directory Listing (DL) predicated upon geographical relevance
• Discounted inbound toll-free (with RespOrg portability)
• Dynamic load balancing across multiple locations
• Business continuity
• Extra Toll-free Numbers (XTF)

Although pricing for SIP Trunking is typically 40 - 70% below what legacy Telcos can offer, the features that enhance functionality and scalability and solve multiple issues related to large-scale enterprise deployments, are the key considerations in the deployment of SIP Trunking. Below are some of the instant benefits of SIP Trunking.

• Instant Cost Savings - Realize immediate cost saving by converging your local, long distance and broadband Internet services onto a single pipe with dynamic bandwidth allocation.
• Economical Local and Long Distance - Reduce toll charges from SIP origination/termination services to the PSTN for local and long distance calls.
• Relieve Hardware Costs - Reduce or eliminate costs associated with purchase, support and maintenance of hardware media gateways.
• Legacy System Compatibility - Preserve existing capabilities with seamless integration into existing systems.
• Geographic Abstraction of DID's - With SIP Trunking, choose DID's from around the country and have them served to the central PBX, mitigating all the complexity associated with centralized PBX's.
• Disaster Recovery - Enable faster, more efficient disaster recovery with an IP network's distributed architecture, inherently more fault tolerant than fixed line, circuit-switched counterparts.
• Flexibility - Allow selection of a single SIP Trunk, increasing the flexibility and ease of adding, subtracting or changing a line.
• Instant Scalability - Add capacity as needed and control monthly recurring costs.