什么是DPI?

DPI: Deep Packet Inspection(深度包检测).

DPI(Deep packet inspection)(or sometimes
complete packet inspection) is a form of
computer network packet filtering that
examines the data and/or header part of a
packet as it passes an inspection point
, searching for non-protocol compliance
, viruses, spam, intrusions or predefined
criteria to decide if the packet can pass or if it needs to be routed to a
different destination, or for the purpose of collecting statistical
information. This is in contrast to shallow packet inspection (usually
called just packet inspection) which just checks the header portion of
a packet.

Deep packet inspection (and filtering) enables advanced security
functions as well as internet data mining, eavesdropping, and
censorship. Advocates of net neutrality fear that DPI technology
will be used to reduce the openness of the Internet. DPI is currently
being used by the enterprise, service providers and governments in a
wide range of applications.