All of the latest IP phone systems, including those from ShoreTel, support Session Initiation Protocol (SIP). SIP is a standard protocol for initiating, modifying or terminating an interactive user session that involves multimedia such as voice, video or chat. SIP enables the network to invite, identify and deliver services to users regardless of location during unicast or multicast sessions.
SIP trunking connects a private branch exchange (PBX) to the Internet using a voice over IP (VoIP) network. By replacing the traditional phone trunk with an Internet connection between the organization and the carrier’s network, SIP trunking makes it possible for both fixed and mobile users around the world to communicate.
Traditional Primary Rate Interface (PRI) is generally more expensive and less flexible than SIP trunking. PRI is a physical connection on a dedicated line that only supports voice communication. SIP trunking is a virtual connection that gives users text and instant messages, conferencing, presence and other real-time services as well as local and long-distance calling.
Although PRI offers guaranteed Qualify of Service, it can only support 23 simultaneous calls. An SIP trunk connection’s capacity depends upon bandwidth, not physical hardware. SIP trunking can be scaled and have capacity added by simply changing software and configurations, while PRI requires new circuits and hardware to be installed.
SIP trunking enables organizations to reduce the cost and complexity of telecommunications while taking advantage of real-time communications and collaboration tools. Long distance costs are much lower with SIP trunking. You can get rid of IP-PSTN gateways, and related costs and headaches, because SIP trunking connects users to the Internet Telephony Service Provider (ITSP) without using the switched phone network. New services and functionality can be integrated with an existing PX to add even more value to your communications infrastructure.
SIP trunking can be deployed by connecting your company to an ITSP through an IP-PBX or a mediation server, which encrypts, decrypts and translates data. Connections can be made through a dedicated line that is unshared, a dedicated line that is shared with other traffic, or the public Internet.
Despite these benefits, many organizations fail to take full advantage of SIP trunking because of challenges during implementation. SIP is a standard, but that doesn’t mean all manufacturers’ equipment and service provider solutions will be compatible with your system. There are also varying pricing models, fees, and backup and redundancy costs. You need to understand how a provider will deliver services to you, what upgrades you might need to make to receive those services, and how much those upgrades will cost. Further, SIP features are not standard. Proper configurations and testing are required to make the system do what your company needs it to do.
IPC is hosting a series of seminars and webinars that will explain SIP trunking, how it saves money, and what factors to consider when choosing a solution and provider. Contact us to learn from our experts and get up to speed on this approach to corporate communications.