Moses

Using the dialer map does not have anything to do with whether the BRI is used for DDR or not. The dialer map serves to indicate how the BRI should connect: what number to dial, what IP address to expect, perhaps what the remote name is and perhaps whether to enable forwarding of broadcast/multicast. The alternative to dialer map is the dialer string if you want to only indicate what number to dial.

If you want both channels you can define a load threshold.

You are enabling the BRI to dial out and potentially to receive calls. If you want to connect and not know who you have connected to then you do not need ppp authentication (typically you do not want ppp authentication when it is a leased line with ppp). For I dial connection I would surely want to authenticate. But the decision is up to you.

If you want the BRI to come up and stay up you probably want a very broad definition of interesting traffic in the dialer group and dialer list. And you probably want to configure a very long inactivity timeout.

HTH

Rick