I want to buy an FXO and FXS card for my 3640 router to practice some configs in the ONT track. Looking at my show Diag, do I need to get a card equipped with a DSP module or am I fine?
With a 3640 router, you are going to need a NM-1v or NM-2v to plugin in your FXO/FXS cards. The network module usually ships with a dsp module.
So yes, you will need a a network module equipped with dsps.
So you will need to buy, NM-1v or NM-2V, FXO, FXS card for your setup.
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