When considering transitioning from traditional circuit-switched voice services to session initiation protocol (SIP) services, the conversation between industry providers and their business customers often is reduced to “saving money.” Though this is often the case, businesses should consider deploying SIP for many of the same reasons they started buying primary rate interface (PRI) connections years ago, but more importantly for the numerous applications that are available and soon to be available.
PRIs had some advantages over analog lines. Lower price sometimes was an advantage. But that wasn’t always the adoption driver. PRI links could deliver caller ID and hotel/motel information services and valuable features for call centers that needed automatic number identification or caller ID data. In many cases, it was multiple hunt groups, direct inward dial features, call tracking, call reporting, computer-telephony integration, access to out-of-rate center DIDs, least-cost routing and management simplicity that actually provided the value. Also, analog lines required that carriers reprogram “line pools” when a business needed to make changes. With a digital PBX and PRI, businesses could make the changes independently.
In other words, application features often were a more-important consideration, and that is also true for SIP services. SIP supports multiple forms of communication and too many applications to count so its value extends far beyond the handling of simple voice calls.
SIP trunking and IP phone systems support PC-based softphones and IP phones connected to the Internet, allowing workers at remote locations to have full access to all features, regardless of location. Employees can use an IP phone or softphone at their home office and an IP-only phone in the corporate office, both registered to the same number, with all inbound calls to one phone number ringing at both locations, if desired.
Though it is not quite so obvious, some of the big innovations that businesses will be able to leverage from IP telephony systems have to do with applications such as presence, instant messaging, file transfers, conferencing, application sharing, white boarding and video conferencing, among other applications that also use SIP protocols. Moreover, if a customer requires additional SIP call paths, the request can be managed as an “add” and it can usually be done quickly. In the TDM world, that’s a new order and more often than not at least a four-week process.
The demand for SIP trunking largely is driven by adoption of SIP-capable IP PBXs, and the number of business organizations adopting such phone systems is growing annually. Indeed, TelePacific engineers are continually testing interoperability and certifying various IP PBXs that can be used with our SIP network connection service. Our latest list of certified IP PBXs:
- Allworx 6x and 24x, version 7.0.3.1 or higher
- Asterisk-derived systems, version 1.4.x and 1.6.x or newer
- Avaya IP Office, version 6.1.5
- Cisco Call Manager Express with ISR 28xx and 38xx series
- Cisco Call Manager 7.x version
- Interactive Intelligence
- Mitel 3300 MCD
- ShoreTel 8.1, 9.0 and 10.2
- Toshiba CIX series 40, 100, 200, 670 and 1200
- NEC UNIVERGE SV8100 version 5.0.1 or higher
Equally important is that more and more businesses have access to low-cost, high levels of bandwidth and use it to integrate voice and data applications using SIP. With SIP over EoC (Ethernet over Copper), EoTDM (Ethernet over TDM) or EoF (Ethernet over fiber), for example, concerns over quality of service have been neutralized because we can provide service level agreements (SLAs). That is significant, and one of the reasons why so many of our customers are increasingly eager to introduce SIP to their network environment.
If you would like to learn more about our SIP services and related features, please contact your TelePacific representative, or local office.



