Compare Filtering Technologies

This table compares software and hardware methods of filtering Internet content currently applied end users, ISPs and at Carrier level.

Technology	Effect on Network Performance	Typical Application	Support Requirements	Security	Ease of Implementation	Number of URLs blocked	Per User Cost	Effectiveness	Per user profiles
DNS Poisoning	None	ISPs, Carriers	Low	Med	Easy	Thousands	Low	Med (overblocking risk)	no
IP address blocking	Low	ISPs	Med	High	Med	Thousands	Low	Med (overblocking risk)	no
PC-Based software	Medium	Homes, Schools	High	Low	Hard	Millions	High	Med	yes
PC-Based client-server	Low	Homes, Schools	Med	Med	Med	Millions	Med	Med	yes
Proxy-based Filtering software	Low-High	Corporate Networks	Med	Very High	Med	Millions	Low	Very High	yes
Analysis-based (dynamic) Filtering Systems	Low-High	Corporate Networks	Med	Very High	Med	Millions	Low-Med	Very High	yes
Pass-by Filtering Appliance	None	Corporates, ISPs	Low	Very High	Easy	Millions	Low	Very High	yes
Hybrid BGP and URL Filter	None	ISPs, Carriers	Very low	High	Very Easy	Thousands	Very low	Very High	no