Inter-domain federation is the feature within unified communications (UC) systems that provides full multi-modal communications between enterprises and also between enterprises and consumers, over an IP network (e.g. the Internet). Unfortunately, the only current federation implementations are between users of Microsoft Office Communications Server 2007/R2/Lync as well as between the users of Cisco Unified Communications System Release 8.0.
 
nbsp; Anyone who has experienced UC will know what a great enabler it can be. However, if the only people with whom you can communicate are your colleagues, then the utility is necessarily limited. Unless you are a telecommuter, or work in a small company or branch office, the option to meet directly with colleagues is usually available. The power of UC is in facilitating long-distance interactions that are as rich as those that you may have with the person who works just down the hall.

From a technical and risk management perspective, setting up an inter-domain UC session (i.e. across the Internet) is not the same as setting up an intra-domain session (i.e. within the corporate firewall and within the same UC system). Challenges for establishing inter-domain sessions are exponentially greater, and include: 
 
• Inter-vendor interoperability
• Security in an insecure environment (i.e. the Internet)
• Ensuring privacy while enabling ‘discovery’
• Real-time media traversal of NATs and Firewalls
• Ensuring audio/video quality over the Internet

If you are not a customer of Cisco and Microsoft, or if you need to federate with a business associate who is a customer of a different UC vendor, then you currently have few options. However, a way forward would be the emergence of a new type of Session Border Controller that I will call a federation gateway. Most of the technologies required to mitigate the issues described above are already features of an SBC. Most SBCs also include ‘intermediation’ capabilities; this is to say that non-interoperable SIP messages and codecs can be tweaked or transcoded by the SBC by implementing configurable policies and profiles. Such a device would enable federation from (just about) any-to-any UC system, particularly for the ‘vanilla’ modalities (e.g. IM&P [instant messaging and presence], voice and video). 

I am not currently aware of any shipping federation gateways from the SBC vendors, but I know from discussions with clients and industry contacts that this concept is being actively worked upon by several vendors. Having only just ‘crossed the chasm’, UC has yet to reach the level of deployment where we might reasonably expect any given business associate to already be a UC user. Once that happens, inter-domain federation will rapidly turn from a nice-to-have to a must-have feature. At the time of writing, Cisco and Microsoft, in line with their position in the Gartner UC Magic Quadrant, are the leaders in this space. However, the key to this market is ‘any-to-any’ federation, so the SBC vendors are well positioned to take advantage of this opportunity.

The full version of this paper is at: http://www.ucinsights.com/authored_papers/Federation-Gateways.html


Copyright © 2011, UC Insights. All rights reserved.