ACL --access control list. An ACL is a list kept by routers to control access to or from the router for a number of services (for example, to prevent packets with a certain IP address from leaving a particular interface on the router).
CBAC --Context-Based Access Control. CBAC is the name given to the Cisco IOS Firewall subsystem.
firewall --A firewall is a networking device that controls access to the network assets of your organization. Firewalls are positioned at the entrance points into your network. If your network has multiple entrance points, you must position a firewall at each point to provide effective network access control.
The most basic function of a firewall is to monitor and filter traffic. Firewalls can be simple or elaborate, depending on your network requirements. Simple firewalls are usually easier to configure and manage. However, you might require the flexibility of a more elaborate firewall.
ICMP --Internet Control Message Protocol. An ICMP is a network layer Internet protocol that reports errors and provides other information relevant to IP packet processing.
RPC --remote-procedure call. A RPC is the technological foundation of client or server computing. RPCs are procedure calls that are built or specified by clients and are executed on servers, with the results returned over the network to the clients.
RTSP --Real Time Streaming Protocol. RTSP enables the controlled delivery of real-time data, such as audio and video. Sources of data can include both live data feeds, such as live audio and video, and stored content, such as prerecorded events. RTSP is designed to work with established protocols, such as RTP and HTTP.
SIP --Session Initiation Protocol. SIP is a protocol developed by the IETF MUSIC Working Group as an alternative to H.323. SIP features are compliant with IETF RFC 2543, published in March 1999. SIP equips platforms to signal the setup of voice and multimedia calls over IP networks.
SMTP --simple mail transfer protocol. SMTP is an Internet protocol providing e-mail services.
UDP --User Datagram Protocol. A UDP is a connectionless transport layer protocol in the TCP/IP protocol stack. UDP is a simple protocol that exchanges datagrams without acknowledgments or guaranteed delivery, requiring that error processing and retransmission be handled by other protocols. UDP is defined in RFC 768.