Initiation is SIP's middle name ? it's also what AV pros can expect to go through over the next few years.
Like other open protocols, SIP is a set of guidelines that all vendors must follow in order for their equipment to work with other manufacturers' gear. That interoperability is a plus because it frees AV pros to mix vendors. But there's a catch: Like other open protocols, SIP allows vendors to layer additional features — often referred to as “extensions” — on top of the base standard as way to make their products stand out from the pack or justify a price premium.
“SIP is a very flexible, open standard,” says Tandberg's Lessman. “That means there's a lot of room for people to go their own way with it.”
These additional features don't always work in a multivendor environment, even when all of the equipment is SIP-based.
“Right now, every vendor has a slightly flavored version of SIP,” says Polycom's Smith. “The integrator needs to understand that infrastructure's and endpoint's capabilities may not exactly match. So they need to research this in advance before they promise certain features and capabilities.”
That situation isn't new to early SIP adopters such as MaRS. “SIP is easy to understand,” says Robert Smith. “As you get more granular with the deployment, there are non-standard things happening between vendors.”
Things can get even trickier when the SIP-based AV gear has to work with SIP-based telecom gear, such as a PBX. Even though they all use SIP, AV and telecom vendors often have different priorities, which are reflected in their support — or lack thereof — for value-added features that other manufacturers include. When it was evaluating SIP equipment, MaRS found that one vendor's PBX worked fine with another vendor's videoconferencing endpoint.
“But once you put it in a live production environment, you find some of the little things,” Smith says. “You start to realize that there are non-standard things.”
The good news is that those interoperability issues should become less common over the years. That's because although vendors will always provide additional features beyond the base SIP standard, there will be more and more real-world deployments to study as a way of identifying conflicts such as unsupported features.
“My advice to anyone who's looking to deploy SIP today is to do your homework, and make sure you test in the scenarios you want it to perform in,” says Tandberg's Lessman.AV meets IT — again
SIP is part of a larger trend where AV, IT, and telecom are slowly converging. So working with SIP means understanding the basics of IT and telecom.