As for deployment types, "most unified communications deployments within large enterprises ... tend to focus around IP PBX investments" while "a typical [SME] ... could deploy voice over broadband (eg. cable or DSL), managed/unmanaged IP PBX, hosted IP Centrex or SIP trunking. Calendaring and e-mail capabilities could be provided by Microsoft, IBM or others; IM and presence could be provided by free services such as Skype, Yahoo or Google."
The vendor selection approach between the large enterprise SME also differs. Since large enterprises "tend to have sizeable IT budgets, as well as ample internal resources and expertise around a number of areas, there is a tendency to go for a best-of-breed approach for unified communications." The SME, on the other hand has limited resources so tends to pick the unified communications vendor based on value-added resellers and local suppliers. Rather than looking at one vendor as the panacea to their business challenges, they will attempt to deploy solutions from multiple vendors and trade off between managing them in-house or via a third party.
Finally, our colleagues offer this advice: "Enterprise customers are correct to take a 'wait and see' approach; SMEs should continue to focus on unified communications point products that add immediate benefit or value; large enterprises and SMEs should consider solutions from carriers that have a good mix of strategic partners from the hardware and software side, as well as mobile network operators; and large enterprises and SMEs should continue to pressure their existing suppliers for tighter mobile integration with unified communications services."