Us: native IP from the ground up
Them: bolted together technologies or IP-enabled PBXs

Us: flexible licensing
Them: expensive software licensing

Us: built-in unified communications &
contact center
Them: add-on capabilities

Us: scales with plug-and-play ease as
you grow
Them: forklift upgrades

Us: single, easy-to-use management
interface
Them: complicated to administer

Us: reduced operating costs guaranteed
Them: high ongoing costs are built-in