7. GLOSSARY AND ACRONYMS
tablish and maintain Internet protocol connec-
tions across gateways that implement network
address translation (
NAT
).
NTP
Network Time Protocol (NTP) is a net-
working protocol for clock synchronization be-
tween computer systems over packet-switched,
variable-latency data networks.
OpenVPN
OpenVPN implements virtual pri-
vate network (
VPN
) techniques for creating se-
cure point-to-point or site-to-site connections. It
is possible to create four different tunnels.
PAT
Port and Address Translation (PAT) or Net-
work Address Port Translation (NAPT) see
NAT
.
Port
In computer networking, a Port is an
application-specific or process-specific software
construct serving as a communications endpoint
in a computer’s host operating system. A port is
associated with an IP address of the host, as
well as the type of protocol used for communi-
cation. The purpose of ports is to uniquely iden-
tify different applications or processes running
on a single computer and thereby enable them
to share a single physical connection to a packet-
switched network like the Internet.
PPTP
The Point-to-Point Tunneling Protocol
(PPTP) is a tunneling protocol that operates at
the Data Link Layer (Layer 2) of the OSI Ref-
erence Model. PPTP is a proprietary technique
that encapsulates Point-to-Point Protocol (PPP)
frames in Internet Protocol (IP) packets using
the Generic Routing Encapsulation (
GRE
) pro-
tocol. Packet filters provide access control, end-
to-end and server-to-server.
Root certificate
In cryptography and com-
puter security, a root certificate is either an un-
signed public key certificate or a self-signed cer-
tificate that identifies the Root Certificate Author-
ity (CA). A root certificate is part of a public key
infrastructure scheme. The most common com-
mercial variety is based on the ITU-T X.509 stan-
dard, which normally includes a digital signature
from a certificate authority (CA).
Digital certificates are verified using a chain of
trust. The trust anchor for the digital certificate is
the Root Certificate Authority (CA). See
X.509
.
Router
A router is a device that forwards data
packets between computer networks, creating
an overlay internetwork. A router is connected
to two or more data lines from different net-
works. When a data packet comes in one of the
lines, the router reads the address information
in the packet to determine its ultimate destina-
tion. Then, using information in its routing ta-
ble or routing policy, it directs the packet to the
next network on its journey. Routers perform the
traffic directing
functions on the Internet. A data
packet is typically forwarded from one router to
another through the networks that constitute the
internetwork until it reaches its destination node.
SFTP
Secure File Transfer Protocol (SFTP) is
a secure version of File Transfer Protocol (FTP),
which facilitates data access and data transfer
over a Secure Shell (SSH) data stream. It is part
of the
SSH
Protocol. This term is also known as
SSH File Transfer Protocol.
SMTP
The SMTP (Simple Mail Transfer Proto-
col) is a standard e-mail protocol on the Internet
and part of the TCP/IP protocol suite, as defined
by IETF RFC 2821. SMTP defines the message
format and the message transfer agent (MTA),
which stores and forwards the mail. SMTP by de-
fault uses TCP port 25. The protocol for mail sub-
mission is the same, but uses port 587. SMTP
connections secured by SSL, known as
SMTPS
,
default to port 465.
SMTPS
SMTPS (Simple Mail Transfer Protocol
Secure) refers to a method for securing SMTP
with transport layer security. For more informa-
tion about SMTP, see description of the
SMTP
.
SNMP
The Simple Network Management Pro-
117
09-05-16
LUCOM GmbH * Ansbacher Str. 2a * 90513 Zirndorf * Tel. 09127/59 460-10 * Fax. 09127/59 460-20 * www.lucom.de
w
w
w
.luco
m.d
e
inf
o@lucom
.de
