Application Inspection Support for Voice over IP
The steady growth of voice over IP (VoIP) technology has also seen the development of new
standards. IP phones and devices, unlike their regular phone counterparts, are not fixed to a
specific switch device, so they must contain processors that enable them to function and be
intelligent on their own, independent from a central switching location. Regular phones are
relatively inexpensive because they do not need to be complex; they are fixed to a specific
switch at a central switching location. Why is this important to you? Well, you might be
running a network that supports VoIP and would want a firewall that supports the different
protocols that are involved with it. Security Appliance support application inspection of the
major protocols and applications that provide VoIP services including the following, each of
which is discussed in the following sections:
■ Computer Telephony Interface Quick Buffer Encoding (CTIQBE)
■ H.323
■ Media Gateway Control Protocol (MGCP)
■ Skinny Client Control Protocol (SCCP)
■ Session Initiation Protocol (SIP)