Telos Zephyr Xstream - Manual (Page 362)

USER’S MANUAL
Appendix 10 – Glossary 350
DCE‐ Data Communication Equipment When using serial communications 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 The 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 extension). DID requires special DID trunks or ISDN PRI “two‐way DID”
trunks. Blocks of DID numbers (typically 10 or 20, sometimes higher) are purchased from the LEC
or CLEC for use on the PBX. The number of DID numbers usually substantially exceeds the
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.
The PBX uses the DID number given it by the phone company to route the channel to the correct
DID extension within the PBX. This allows some or all PBX stations to receive calls directly
without going through an attendant (or auto attendant) 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) The Utility menu on the Zephyr where the 7 digit Directory Numbers
can be entered during set up. The 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. This 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) Causing 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 The 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.