Telos Zephyr Xstream - Manual (Page 361)

USER’S MANUAL
Appendix 10 – Glossary 349
Also called a Both Way Trunk. This is not the same as a Two‐ way DID trunk. See DID trunk, Hunt
Group and Trunk.
Common Channel Interoffice Signaling See CCIS
Competitive Local Exchange Carrier See CLEC.
Concentration The basic premise is to share facilities wherever possible. For instance, while
there may be thousands of customers served by a given Central Office, there will be
substantially less than that number of calls which can be handled simultaneously. And, even
fewer long distance calls can be made simultaneously. The art of Traffic Engineering is to have
enough capacity that calls are rarely blocked, but no more than that number. See also Choke
Exchange and Blocking.
CPC‐ Calling Party Control Sometimes referred to as "CPC Wink" or "disconnect supervision". A
call supervision feature on an analog loop start line that provides the ability for a CO (Central
Office) to signal the called party when the calling party hangs up. CPC allows the PBX, key
system, or telephone answering device to reset the line so that it is ready to accept or initiate
another call. CPC is accomplished by either a loop current drop or reversal. With some CO
equipment, it is also provided if the called party drops the call. See also MCLD.
CPE‐ Customer Premise Equipment Customer owned equipment located at his/her facility, such
as a CSU or terminal. In the USA and Canada, the NT1 is part of the CPE.
CPN ‐ Called Party Number European Term. The number that has been dialed. See Called Party
Address.
CSD‐ Circuit Switched Data A dial‐ up data communications channel which, once established,
looks like a transparent data pipe. Also, the type of ISDN service required to utilize this capability
of an ISDN circuit. In contrast to CSV.
CSU‐ Channel Service Unit The NCTE used in the USA & Canada to terminate a T1 line. Typically
the CSU must be provided 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 commonly 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 required 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. The Northern Telecom DMS‐100 switch Supports “DMS
Custom Functional" ISDN. The AT&T/Lucent 5ESS switch Supports “Custom Point‐ to‐ Point”
(PTP) and Custom Point‐ to‐MultiPoint (PMP). The 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. The 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.