This article originally appeared in the March 2011 issue of INTERNET TELEPHONY.
At ITEXPO in Miami, many presentations focused on the crucial role interoperability plays in SIP implementations. Now that SIP trunking is here to stay and unified communications is truly taking off, end users, VARs and service providers are all facing the interoperability challenge: For years deployments have been at the whim of what equipment was available at the time, price point, capability. Now that technology and market demand are in sync, the challenge has been integrating the hardware and software in which we’ve invested so heavily, to have them all come together to enable unified communications.
One problem with interoperability is the many flavors of SIP. Some manufacturers build their equipment, or bill their service, as SIP. But SIP is an inexact protocol, and vendors use different but compliant methods to perform the same function within the protocol. These variations may be slight, but in the end can prove to be a significant stumbling block in deployments.
They also impact security. Opportunities for hackers, spoofers, etc., are easy to come by when there are inconsistencies between the SIP-enabled PBX and the ITSP. Leading IP PBXs and ITSPs are conducting interoperability testing aggressively; make sure your equipment and service providers have demonstrated successful interoperability with one another.
Pave the way for interop by using products that strictly adhere to the SIP protocol. There are a number of advantages vendors can leverage with SIP that benefit security, advantages that come into play only when the protocol is strictly maintained. This also positions you well in planning your future network.
Specific to SIP trunking is the SIPconnect solution. SIPconnect is a set of technical recommendations or best practices for SIP trunking. It was developed by the SIP Forum to provide a common method for enterprises to connect to a SIP trunking service provider using standard SIP messages consistently across all vendors. SIPconnect is a major step forward toward standardizing interoperability among all of the components of a SIP trunking implementation.
Even with these strides, there are many issues that won’t be resolved in the near term, and the best steps to take in implementing SIP, SIP trunking and unified communications are to install an enterprise session border controller at the edge of the network. The E-SBC normalizes the SIP signaling between the SIP-enabled PBX and the ITSP, allowing the enterprise to connect successfully to SIPconnect-compliant SIP trunking service providers quickly, easily and securely.