Snom ONE IP, Техническое руководство

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snom ONE • Administrator Guide, Release 5
548
by the computer’s processor. RAM is quickly readable and writeable compared to
other kinds of computer storage (e.g., the hard disk, floppy disk, and CD-ROM);
however, data in RAM remains only as long as the computer is running. Once
the computer has been turned off, RAM loses its data. When the computer is
turned on again, the operating system and other files are once again loaded into
RAM.
RFC (Request for Comment)
A memorandum published by the Internet Engineering Task Force (IETF) de-
scribing methods, behaviors, research, or innovations applicable to the working of
the Internet and Internet-connected systems. RFCs are used either for peer review
or to simply convey new concepts and information. The IETF adopts some of the
proposals published as RFCs as Internet standards.
Router
A device for connecting one or more computers to other computers, networked
devices, or to other networks. Compared to hubs and switches (which are also
connecting types of devices), a router is the smartest and most complicated of
the three. Routers can be programmed to understand and route the data its being
asked to handle. Configuration is done through a user interface. Larger routers
are capable of being programmed to communicate with other routers to deter-
mine the best method of getting network traffic from point A to point B. Hubs
work at the data link and network layers (layers 2 and 3) of the OSI model.
RTCP (Real-time Transport Control Protocol) [RFC 1889, RFC 3550]
An Internet protocol used to synchronize streams (e.g., the time stamps of a video
stream with the time stamps of an audio stream). RTCP works hand in hand
with RTP (which does the delivery of the actual data) and sends control packets
to participants in a call (in a manner scalable to large multicast networks). The
primary function is to provide feedback on the quality of the data distribution
being provided by RTP. See “RTP.”
RTP (Real-time Transport Protocol) [RFC 1889, RFC 3550]
An Internet protocol used for transmitting real-time data, such as audio, video or
simulation data, over multicast or unicast network services. RTP addresses jitter
and out-of-sequence datagrams by assigning timestamps and sequence numbers
to the packets. The sequence number in the RTP header enables the receiver to