Optimize Cisco CallManager – Use IP address, not servername
Contributed by Al Banks 
Tagged: Cisco call manager In system>server, the default name for each server is it’s hostname. These names will be passed along to the phones, requiring a DNS lookup before a phone can contact CallManager.
To prevent the phones from needing to contact DNS, change each server’s name in system>server to its IP address. This way, the address will be passed to the phones, not the hostname.
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