HP ProCurve 7000dl Series Basic Management And Configuration Manual page 848

Appendix B: Glossary
Multiplexing Combining and transmitting multiple signals over a single channel. Also
Multiplexer Also known as a MUX. A communications device that multiplexes (combines)
M13 Multiplex 1-to-3. A device that converts 28 T1 inputs into a single T3 output.
NAT Network Address Translation. An application created to ease conserve IP
NAT D NAT Discovery. Packets exchanged during IKE phase 1 that include hashes of
NAT T NAT Traversal. Provides address and port translation for packets traveling
NCP Network Control Protocol. A group of protocols within the PPP suite. NCPs
NEBS Network Equipment Building Standards. A set of technical requirements
B-34
known as "muxing." The most important type of multiplexing for data transfer
is time-division multiplexing (TDM), which is used with digital signals. See
also TDM.
signals from multiple sources for transmission over a single medium.
N
addresses. NAT acts as a gateway between a two networks, translating IP
addresses used in one network to different IP addresses known within another
network. Typically, NAT translates many private network addresses to one or
a few public IP addresses. For more information on NAT, see RFC 3022 (at
http://www.ietf.org/rfc/rfc3022.txt).
devices' source and destination IP addresses and ports. Devices attempting to
create a VPN connection can exchange NAT D packets to determine whether
and where NAT is used between them. In this case, peers must use a NAT-
traversal (NAT T) over the VPN connection. See also NAT T.
through an IPSec VPN. Because NAT alters information in a packet's IP header,
it can cause the packet to fail IPSec security checks. NAT T encapsulates
packets in a UDP/IP header with the translated IP address, leaving the IPSec
packet untouched. For more information on NAT Traversal and NAT Discov-
ery, see RFC 3947 (at http://www.ietf.org/rfc/rfc3947.txt).
carry information about how to manage higher-level protocols, primarily
Network Layer (Layer 3) protocols. Each Network Layer protocol that can be
encapsulated in a PPP frame has a separate NCP with its own configuration
options. When establishing a PPP session, peers exchange the NCP for the
Network Layer protocol used by the packets that they will send across the
link. See also IPCP, IPXCP, PPP, and SNACP.
designed to make central office equipment and switches error proof. These
requirements cover spatial, hardware, interface, thermal, fire resistance, han-
dling and transportation, earthquake and vibration, airborne contaminants,
grounding, acoustical noise, illumination, EMC, and ESD requirements. NEBS