Telos NX12 Cell Phone User Manual


 
106 | Appendix 2
number of trunks in the system.
DID Trunk- A Direct Inward Dialing Trunk. A trunk (channel)
which can only receive calls. A group of telephone numbers (DID
numbers) are associated with a given trunk group, however there
is no one-to-one correspondence between the individual channels
and these numbers. e PBX uses the DID number given it by the
phone company to route the channel to the correct DID extension
within the PBX. is allows some or all PBX stations to receive
calls directly without going through an attendant (or auto atten-
dant) Note that there are usually more DID numbers than there are
DID trunks. See DID number and DID extension.
Direct Inward Dialing- See DID
Directory Number (USA & Canada)- Your seven digit telephone
number (without the area code), as found in the telephone directory.
Directory 1&2 (Zephyr)- e Utility menu on the Zephyr where
the 7 digit Directory Numbers can be entered during set up. e
Zephyr generally does not require these numbers.
DN- See Directory Number. See also Directory 1 &2 and MSN/
DN 1 &2.
DNIS- Dialed Number Identification Service- A service, typically
offered by a long distance company on 800 lines, that provides the
number dialed by the caller. is allows a caller to receive specific
treatment depending on the number dialed.
DP - Dial Pulse. A method off sending address information by
either 1) Causing brief interruptions in loop current. or 2) Caus-
ing brief changes of state of a bit on a digital circuit using Channel
Associated Signaling. In other words, “rotary” or “pulse” dialing. See
also DTMF and CAS.
DSØ- Digital Signal Level Zero. e smallest unit of measure of
the standard rate hierarchy used by the Telcos (i.e. all other rates are
a multiple of the DSØ rate. For example, the T1 rate is 24 times the
DSØ rate and the E1 rate is 32 times the DSØ rate). 64 kbps. See
also B channel.
DS1-Digital Signal Level 1. e second level up the digital rate
hierarchy used by the Telcos. is is 24 times the DSØ rate for a
total of 1.544 mbps. See DSØ. See also T1.
DS2-Digital Signal Level 2. Data rate of 6.312 mbps (4 times the
DS1 rate). See DSØ and DS1.
DS3-Digital Signal Level 3. Data rate of 43.232 mbps (28 times
the DS1 rate). See DSØ and DS1.
DSL- Digital Subscriber Line. Traditionally refers to an ISDN
circuit or sometimes a T1 line, although the term is also frequently
used to mean the next generation beyond ISDN. Sometimes xDSL
is used to indicate that the writer is referring to any of a number of
emerging DSL technologies.
DSU- Data Service Unit. See CSU/DSU.
by the end user. See NCTE and DSX1
CSU/DSU- A device which incorporates the functions of a CSU
(Channel Service Unit) and a DSU (Data Service Unit) Most com-
monly it interfaces between a Switched-56 or Dedicated Digital
Service circuit and a user’s data equipment such as the Zephyr.
CSV- Circuit Switched Voice- A dial-up communications circuit
for voice grade communication. Also, the type of ISDN service re-
quired to use this capability of an ISDN circuit. In contrast to CSD
Custom ISDN (USA & Canada)- An ISDN protocol which
pre-dates National ISDN-1. In most cases National ISDN-1 is
also available. e Northern Telecom DMS-100 switch Supports
“DMS Custom Functional” ISDN. e AT&T/Lucent 5ESS
switch Supports “Custom Point-to-Point” (PTP) and Custom
Point-to-MultiPoint (PMP). e ISDN protocol has no relation to
where one may call. Telos equipment does not support PMP.
D Channel- Data/Delta Channel. Depending on who you ask, it
is Data or Delta. e channel which handles ISDN network-related
data between the user’s equipment and the Telco switch. Used to
carry data to set up calls and receive calls. Some Telco’s also allow
users to use the D channel to access the packet data network, with
appropriate terminal equipment.
D4- See Superframe. See also Line Format.
DCE- Data Communication Equipment. When using serial com-
munications such RS-232, V.35, or X.21, the DCE is the device
sending/receiving from the Telco line. i.e.: a modem or CSU/DSU.
In contrast to DTE.
DDS- Digital Data System- See Dedicated Digital Service.
Dedicated Circuit- A permanent channel between two locations. As
opposed to a Switched Circuit.
Dedicated Digital Service- a “Hardwired” or “Nailed Up” digital
circuit which is permanently connected between 2 points. Typically
56Kbps or 64Kbps. Dedicated digital lines are frequently cheaper
than ISDN for full time service. Also called Digital Data System or
DDS.
DID- Direct Inward Dialing. e ability for an outside caller to dial
to a PBX extension without going through an attendant or auto-
attendant. See also DID Number and DID Trunk.
DID Extension or DID station- A specific phone within a PBX
which can be called from the public telephone network without
going through an attendant or auto-attendant.
DID Number- A phone number used to route calls from the
telephone network to a specific phone in a PBX (the DID exten-
sion). DID requires special DID trunks or ISDN PRI “two-way
DID” trunks. Blocks of DID numbers (typically 10 or 20, some-
times higher) are purchased from the LEC or CLEC for use on the
PBX. e number of DID numbers usually substantially exceeds the