Previous: How do businesses use presence?
Presence functionality can run as an extension of Session Initiation Protocol (SIP), the open standard used in many Voice over IP deployments. As such, if you're running an open standard, SIP-based VoIP system inhouse then presence functionality is often built in or can be easily added.
While monitoring the presence of colleagues within your organisation is relatively straight forward, vendors are also working to allow interoperability between enterprise-grade presence systems.
While some vendors have started to introduce such features, businesses can also deal with interoperability issues by subscribing to a third party presence server. There is some debate as to whether such customers are demanding such features.
Centrix Solutions' Mahdi says he is yet to come across an Australian site that required external presence capabilities.
"There is very little demand for it. I think most organisations haven't yet realised the advantages of presence internally let alone externally," he says.
"A lot of clients would have some fears of integrating to the outside. Presence is about productivity but with presence in many cases comes instant messaging. When you're integrating with external systems and opening up instant messaging, that can be deemed productive or not depending on the environment."
Alternatively, Microsoft's strong collaboration focus with products such as Office 2007 and Sharepoint sees it strongly pushing inter-organisational presence.
"A lot of people only think about presence inside their own firewall, but one of the areas that Microsoft spends a lot of time in talking to businesses about is presence outside your organisation, such as presence of your customer or your supplier," says Microsoft's Trimboli.
"Presence can work not only inside my organisational boundaries but also with people who are connected to me and federated to me outside my organisational boundaries, like business partners and customers. As XML is to data exchange, SIP is to voice, video and presence information exchange. You can't have unified communications from one vendor only, the industry needs to work together."
Cisco also sees the value of federation, but Hughes says the industry has some way to go before the vision becomes a reality.
"It's still a little bit immature from a standards perspective, there's still a way to go with interoperability based on standards like SIP and SIP/SIMPLE with this notion of federation. For example we federate to Microsoft, but Microsoft doesn't federate to us."