IBM 8275-416, User Manual

Page: 151 / 156

Protocol Number. The port or program number as defined by the parent protocol. For example, if you are adding a
TCP child protocol, the protocol number will be the TCP port number.
PSTN. Public switched telephone network.
RMON. Remote MONitoring. Subset of SNMP MIB II which allows monitoring and management capabilities by
addressing up to ten different groups of information. Defined in IETF document RFC 1757.
RMON2. Extends the capability of RMON to include protocols above the MAC layer.
Short Packet. See undersize packets.
Station. Any machine connected to the network - for example a fileserver, PC, workstation, printer or probe.
Subnet Mask. A filtering system for IP addresses. It defines the portion of the IP address used to identify the subnet.
The remaining portion is used to represent host information. Devices and routers use the mask to identify the subnet
on which a probe resides.
System Descriptor. A free-form field on RMON devices used by vendors to supply basic information about the
device.
Transport Layer. The fourth layer of the OSI network layer model. This is responsible for error checking and
correction, and some message flow control.
Trigger. A trigger represents a sequence of events that may occur on a network. When these events occur, an alarm
is triggered.
Undersize Packets. An Ethernet packet less than 64 octets long (excluding frame bits but including FCS octets) but
otherwise well formed.
Virtual Circuit. Circuit-like service provided by the software protocols of a network, enabling two end points to
communicate as though connected by a physical circuit. Network nodes provide the addressing information needed in
the packets that carry the source data to the destination.
Glossary
135