Can POTS phones directly connect to the U1900?
56POTS phones cannot directly connect to the U1980, but can connect to the U1980 through the IAD.
The U1910, U1930, U1911, U1960, and U1981 that have been configured with the ASI board or OSU board support the direction connection to POTS phones.
The user capacity of the U1981 and U1960 is large, so it is recommended that POTS phone connect to the U1981 and U1960 through the IAD.