Maybe this is a stupid question to ask, but why would Cisco release a phone that is not supported by the current release of CCA, especially considering CCA is the only supported method of configuration for the UC500's?
The SPA series handsets and ATAs are widely used in hosted call control environments with SIP proxies from a variety of vendors, so the phones were released as soon as they were fully developed and had successfully completed the QA process. The release schedule for the UC500 did not line up closely enough to this to do a simultaneous release of support across all platforms.
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