Select a domain from the "Exchange UM Dial Plan Forest" combo box to see a list of SIP dial plans that are configured in ...

Select a domain from the "Exchange UM Dial Plan Forest" combo box to see a list of SIP dial plans that are configured in that forest. If you do not see the forest you expect listed, make sure there is a two-way trust relationship with that forest. If you don't see the dial plan you expect, make sure the dial plan is designated "SIP Name" and that you have run ExchUCUtil.ps1 on the Exchange Server.