Zultys MX250, Руководство по оборудованию

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SIP Server. A network device that performs special functions at the request of SIP endpoints.
Servers typically act in response to SIP endpoint requests, but can also initiate functions on their
own. RFC 3261 defines three types of SIP servers: SIP Proxy servers, Redirect servers, and
Registrar servers.
Spanning Tree Protocol (STP). When constructing a network, a second bridge between two
network segments is often installed as a backup. The Spanning Tree Protocol allows these bridges
to exchange information so that only one of them will handle a given message sent between two
computers within a network. Described by RFC 2878, the Spanning Tree Protocol prevents the
condition known as bridge loop.
Subnet Mask. A number that, when applied to an IP address, can identify the subnetwork where
the address resides. For example, within a class B network, a subnet mask of 255.255.255.0
specifies that the first two portions of the decimal dot format are the network number, while the
third portion is a subnet number. The fourth portion is the host number. A subnet mask of
255.255.0.0 species a class B network that does not have a subnet.
Switch. A network device that selects a path or circuit for sending a unit of data to its next
destination. A switch may also include the function of the router. A switch is generally a simpler
and faster mechanism than a router, which requires knowledge about the network and how to
determine the route. A switch is usually associated with layer 2 of the OSI communications
model.
System Controller (SC). One of the boards inside the MX20. It is connected to a hard disc that
stores all of the application software for the MX250 and upon power on, forwards the software to
the other boards in the system. This board also has the console port directly connected to it so that
you can always communicate with the system. The board also controls the LEDs at the rear of the
system that indicate the nature of a problem if the MX250 is unable to start up.
Three-Way Handshake. A triple-exchange of data packets that establishes a TCP connection. The
Three-Way Handshake transpires as follows:
1. The initiator sends a SYN (synchronize/start) packet.
2. The recipient replies with a SYN/ACK (synchronize/acknowledge) packet.
3. The initiator responds with an ACK (acknowledge) packet.
At this point, the connection endpoints are established and data transmission can commence.
Transmission Control Protocol (TCP). A set of communications protocols that, when used with
Internet Protocol (IP), support peer-to-peer connectivity functions for both local and wide area
networks. TCP/IP is a communications protocol which allows computers with different operating
systems to communicate with each other and controls how data is transferred between
computers on the Internet.While IP handles the actual delivery of data, TCP tracks the data
packets into which a message is divided for efficient routing through the internet. The ZIP 4x4
phone supports TCP as described by RFC 793.
Trusted Network. Networks inside your network security perimeter. Only known and approved
sources are allowed access to a trusted network.
Tunneling. The transmission of data intended for use only within a private network through a
public network in such a way that the routing nodes in the public network are unaware that the
transmission is part of a private network. Tunneling is generally done by encapsulating the
private network data and protocol information within the public network transmission units so
that the private network protocol information appears to the public network as data. Tunneling
allows the use of the Internet, which is a public network, to convey data on behalf of a private
network.