Phone normalization rules in OCS 2007 are stored in Active Directory and can be manipulated using Enterprise Voice Route Helper and the OCS 2007 Administration MMC snap-in. The rules are not only used on the OCS server, but they are also downloaded to the client. How is the process?
The rules are updated in Active Directory on the domain controller used by tool. The WMI provider on each front-end server in the pool/standard edition server queries the domain controller it is connected to each 5 minutes for updated rules. So if they are not talking to the same domain controller you will have to factor in Active Directory replication latency.
When the client (OC 2007 or OC 2007 Phone Edition) signs in to the pool they will get configuration information downloaded through in-band provisioning. The phone normalization rules are in the <LocationProfileDescription> XML tag. The client will also re-load the rules each 8 hour.