Rockwell Automation 1761-NET-ENIW MicroLogix Ethernet Interface (ENI) User Manual - Manual (Page 137)

Publication 1761-UM006E-EN-P - August 2005
Glossary 3
Security Mask
The Security Mask, when configured, allows you to restrict incoming
TCP/IP and/or UDP messages to have source IP addresses that are
within some prescribed range. For example, if you wanted to restrict
all message sources to be from within a company’s allocated IP
address range, a Security Mask could be configured that would block
any IP address outside that range.
SMTP (Simple Mail Transfer Protocol)
This protocol defines the interface and commands with the Mail
Transfer Agent and defines how the ENI/ENIW will deliver the
outgoing mail.
Single-Hop/ Multi-Hop
Term that refers to how many “different” networks a message must
traverse to reach its destination. For the ENI/ENIW, a single-hop
message is one whose source and destination nodes are both TCP/IP
end points.
TCP (Transmission Control Protocol)
TCP is one of the main protocols in TCP/IP networks. Whereas the IP
protocol deals only with packets, TCP enables two hosts to establish a
connection and exchange streams of data. TCP guarantees delivery of
data and also guarantees that packets will be delivered in the same
order in which they were sent.
TCP/IP (Transmission Control Protocol/Internet Protocol)
The suite of communications protocols used to connect hosts on the
Internet. TCP/IP uses several protocols, the two main ones being TCP
and IP. TCP/IP is built into the UNIX operating system and is used by
the Internet, making it the de facto standard for transmitting data over
networks.
UCMM (Unconnected Message Manager)
The UCMM is an object defined in the CIP protocol. This object is
responsible for handling connection requests and unconnected
message traffic.
UTP (Unshielded Twisted Pair)
A type of cable used in Ethernet systems.