Yes, but you need to disable the function of SIP Registration first. You can’t use the dialplan to call with remote IP address. You must use the phone book to dial another IP.

[A]. Select [Configuration] -> [VoIP] -> [Configuration], Disable the [SIP Registration] -> [Submit]

[B]. Select [Configuration] -> [VoIP] -> [Phone Book], enter the remote IP address and press [Submit]

[C]. Click [Save Config] to save all of parameters into flash.