not sure what you mean, the AC config requires that the phones that are going to be used by the operators to be associated to a user (the user depends on the version). so not any phone can be used with AC.
is the question regarding Extension mobility?? by the fact you say that the users can log into any phone??
if so there is no way to limit to which phone a user can log in, that's the whole point of EM. if the phone is enabled for EM ANY use can log into it
HTH
HTH
java
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