Currently and as defined by BOLT 07 on the Lightning Network the fees for forwarding an HTLC of amount
amount_to_forward are computed as:
fee_base_msat + amount_to_forward * fee_proportional_millionths / 1000000
I am wondering why the
base_fee_msat was actually included and which concrete problem does it solve that could not be solved if the
base_fee_msat was dropped?