HP ProCurve 7000dl Series Basic Management And Configuration Manual page 829

DLCI Data Link Connection Identifier. In a Frame Relay network, the DLCI is a 10-
bit field within the address field that specifies the PVC path that a particular
frame takes. DLCIs have only local significance; the value is changed at each
switch. DLCI values can be from 0 to 1023. Values 16-991 are reserved for
subscribers to assign to virtual circuits. DLCI values of 0 and 1023 are reserved
for use by Frame Relay management protocols.
DMT Discrete MultiTone. The standard ADSL modulation technique. Bandwidth is
divided into 256 subchannels (bins) of approximately 4 kHz each. In Annex A,
subchannels 1-6 are reserved for analog voice. In Annex B, subchannels 1-30
are reserved for ISDN traffic. The rest of the subchannels are used for ADSL
data except for channel 0 and channel 256, which cannot be used for analog
voice or data. See also ADSL and CAP.
DMZ De-Militarized Zone. A small subnetwork between a trusted internal network
and an untrusted external network. The DMZ is placed to provide an additional
layer of security and separation between the two networks.
DN Directory Number. The telephone number assigned to an ISDN receiver.
DNIS Dialed Number Identification Service. A telephone service that provides the
caller's number to the call receiver. DNIS is a common feature of 800 and 900
lines. If there are multiple 800 or 900 lines for the same company, DNIS tells
which number was called.
DNS Domain Name System. A system that translates URLs to their associated IP
addresses and communicates this information throughout the Internet. DNS
allows users to enter a URL, which is much easier to remember than an IP
address, into their Internet browsers while providing a way for network
devices to find and reconcile the URL with its Internet IP address. For more
information, see RFC 3696 (at http://www.ietf.org/rfc/rfc3696.txt).
Domain Name The URL name associated with a particular IP address (or group of IP
addresses).
DoS Denial of Service. A type of attack designed to disable a server or network
service by bombarding it with service requests. DoS attacks prevent legitimate
users from accessing the resource.
DSA Digital Signature Algorithm. A U.S. government standard for creating and
verifying secure digital signatures. Digital signatures authenticate electronic
documents. One such document is a digital certificate, which peers in a VPN
use to authenticate each other.
Appendix B: Glossary
B-15