There’s a great deal of buzz about SIP
trunking. At the upcoming Internet Telephony Conference & EXPO in Fort Lauderdale, Ingate will be hosting a series of SIP trunking seminars designed to educate end users, VARs, distributors and systems integrators about the benefits, issues and opportunities available to your business thanks to this new technology.
Most of the customers I speak with are interested in the bottom line: what will SIP trunking mean for my business? When do I see a return on my investment?
This article is intended to provide you with a preview of the ITEXPO seminars, offering an overview of SIP trunking and the top five ways any company — large or small — can benefit from SIP trunking.
What is SIP Trunking?
A SIP trunk is the use of SIP (Session Initiation Protocol (News - Alert)) to set up communications over the Internet between a customer location and an Internet telephony service provider (ITSP), which transfers the SIP calls to the PSTN
. Unlike in traditional telephony, where bundles of physical wires were once delivered from the service provider to a business, a SIP trunk is a logical connection from one point to another over the public Internet.
#1. No More BRIs, PRIs or PSTN Gateways
SIP trunking eliminates the need to purchase BRIs (Basic Rate Interfaces), PRIs (Primary Rate Interfaces), or local PSTN gateways, lowering telephony costs. It is much easier and less costly to extend your system over IP
. Going from one E1/T1 to two always requires additional hardware. Even if you move from an E1/T1 to a higher level standard bundle like STM-1 the hardware will need to be replaced.
#2. No More Separate Voice and Data Connections
SIP trunking also reduces costs by eliminating the need for separate voice and data connections, and expands the potential for communications convergence using both voice and data together. Further, as a company grows, all necessary infrastructure to handle additional voice/data traffic is already in place.
A single corporate SIP trunking account can serve an entire enterprise, no matter the size. Also, multi-site enterprises can use a single SIP trunking account rather than multiple sub PRI connections.
# 3. Turn All Calls into Local Calls
The emergence of service providers offering SIP trunks to enterprises means that enterprises can outsource their PSTN connectivity to a third party. This reduces long-distance charges, as SIP calls travel over the Internet or provider’s IP network to a termination point owned by a service provider, where the call is then transferred to the local PSTN.
An example: a company in Sweden using VoIP and a SIP trunking service provider initiates a call to Dallas by using a 001 international dialing prefix to designate a call to the US and the phone number. The call is routed to the SIP trunking service provider over the public Internet which in turn redirects the call to its point of presence closest to the Dallas area. As a result, the call is carried most of the distance over the Internet at no incremental cost, and placed on the PSTN as a local Dallas call.
# 4. Get Rid of Costly 800 Numbers, but Not the Convenience
Instead of providing customers with an “800 number,” a SIP Trunking service provider with points of presence in multiple U.S. cities could establish local numbers in each city for customers to call. Those calls can be terminated locally and placed on the Internet for delivery to the company’s call center.
# 5. Let ENUM Help
ENUM (Telephone Number Mapping) is used to automatically look up phone numbers to determine if they match a known SIP address, allowing the call to be completed over the Internet (instead of transferring it out to the PSTN). Since no traffic is placed on the PSTN, ENUM provides an additional means of cost-savings for businesses that communicate with other firms that use SIP for communications.
Infrastructure and ROI
A relatively small investment is necessary to benefit from the use of SIP-based communications and to enjoy the cost savings that accrue from using a SIP trunking service provider. For the enterprise, converting to Voice over IP usually involves the purchase of an IP-PBX
, IP Phones or soft clients (those which operate on typical PCs or laptops), and a SIP-aware firewall to maintain security while admitting VoIP traffic.
SIP trunking can generate a sizable return on investment and payback the up front costs in a very short time — in some cases in less than six months.
Summary
SIP trunking offers enterprises the benefits of converged communications and saves substantial expense by eliminating the need to purchase BRIs, PRIs or PSTN gateways. It also reduces expenses by terminating calls closer to the called party. A robust enterprise solution combined with a SIP trunk from an ITSP realizes the promise of global connectivity, over the Internet, so long envisioned by the voice over IP pioneers.
Steven Johnson is president of Ingate Systems (News - Alert).
Electronic Numbering (ENUM) | X |
The ITU-T International Telecommunications Union Telecommunications telephone numbering standard that specifies the telephone number-type address format used for ISDN-Integrated Services Digital Netwo...more |
Private Branch Exchange (PBX) | X |
Originally, telephone features were provided by telephone central office switching systems, often called CENTREX.�PBX systems emerged as customers wanted to have more calling features and control over...more |
Internet Protocol (IP) | X |
IP stands for Internet Protocol, a data-networking protocol developed throughout the 1980s. It is the established standard protocol for transmitting and receiving data
in packets over the Internet. I...more |
Session Initiation Protocol (SIP) | X |
SIP is the real-time communication protocol for VoIP. SIP is a signaling protocol for Internet conferencing, telephony, presence, events notification (emergency calling) and instant messaging.
SIP...more |
Public Switched Telephone Network (PSTN) | X |
A PSTN number is a dialed call which is switched or connected via a CO switching system called a Class 5 End office or in SS7....more |