California's connection wit the interstate compact network, continues to change. It is constantly updated. When you were pulled over in Boston, did you have a California or Massachusetts license?
The information you received from the DMV relates to some kind of "hold" on your license based on something reported from Massachusetts. My suggestion is that you ask the DMV to provide you with the information that they received - case number, court location etc. You can also call DMV Mandatory Action at 916-657-7780 for clarification.
You shoud contact an attorney in Boston, who can assist you with clearing the traffic violation either by dismissal or other means, to clear the hold.
Ms. Gorelick's answer is on the money as usual. The sooner you do a Google search for Boston Traffic Ticket Attorney and choose one you like, the sooner you can get that cleared do California also clears you.
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