SIP Trunking blends users’ voice and data connections into a single line to deliver a number of advantages not found in other services—i.e. greater cost efficiency, expanded services, new features, and more. In doing so, SIP Trunking utilizes three main components: IP PBX, ITSP (Internet Telephony Service Provider), and the device that enables connection between these components (aka an edge device). When utilized properly, these components allow SIP Trunking to be quality, secure, and fully functional. Though this sounds simple enough, many users often face difficulties upon first switching to SIP Trunking. While this mode of telephony is not hard to deploy, it can be if users do not account for key variables—namely interoperability.

As stated above, there are only need three essential components SIP Trunking systems need (ITSP, IP PBX, and Border Element); however, it’s important to note that not all of these components are optimized to work with one another. Additionally, while each is crucial to the system, there is not one vendor that offers all three components. That being said, users must retrieve these devices from separate vendors; however, in doing so, they must account for interoperability. In order for a SIP Trunking solution to be fully operational, users must be sure these three components are able to communicate with one another. If communication between these components cannot happen, users’ systems will be substantially inoperable—i.e. SIP trunk calls will not place, the system will be open to security threats, etc.

Generally speaking, whenever users mix equipment in a unified IT environment, problems are more likely to arise. SIP Trunking equipment is no exception. In mixing and matching, users can run into a number of interoperability issues—i.e. the need for software upgrades, gateways, or even SBCs (session border controllers)—all of which can prove disruptive. With that in mind, users need to take appropriate measures to neutralize this threat.

In order to combat interoperability issues effectively, users have a number of different options. For example, users can seek out equipment that’s backed by certification, testing, and/or vendor pledges.  Currently, many vendors conduct tests to ensure users ITSPs and IP PBXs will be able to work together without problems. As such, in selecting equipment from these vendors, users can be sure that they will not face interoperability issues once the solution is deployed.

Although vendors’ certifications and tests can lend peace of mind to users, they may not completely neutralize the threat. That being said, users may want to seek out other options. Another good way of ensuring interoperability is by selecting a SIP based edge device. These devices generally serve as the adapter between the IP PBX and the ITSP. In selecting an edge device that is optimized for (or based in) SIP, users are substantially decreasing the likelihood of operability issues. Another helpful tool in combating interoperability is SIPconnect—“an industry-wide, standards based approach to direct IP peering between SIP enabled IP PBXs and VoIP service provider networks.” Simply put, this develops a standard for users to hold potential vendors to.  While this doesn’t completely neutralize the threat of interoperability issues, it does provide an industry-wide standard—which simplifies interoperability. Last but not least, if these issues continue, users are always able to contact their provider directly. Trouble tickets and live support can help users identify their problem and find ways to remedy it.

While SIP Trunking can help businesses in a number of ways, users need to be sure there system is fully able to. Sure, Interoperability is not the be-all, end-all issue it is often made out to be—especially since there are a number of tools/resources at users’ disposals; however, they can still prove troublesome. Interoperability may not be the harbinger of death, but it can delay, stunt, and harm your system; therefore, it’s important to account for this threat when selecting equipment.