Telos Zephyr Xstream User Manual
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USER’S MANUAL
Appendix 10 – Glossary 362
Telos Test Line (Xstream, Zephyr & ZephyrExpress) 24 Hour test line which can be called to
verify correct operation of your Zephyr or ZephyrExpress codec. Numbers are +1 216‐ 781‐ 9310
and +1 216‐ 781‐ 9311. The test line transmits in dual/mono mode at 32kHz and can be received
in L3 Mono using one B channel or L3 Stereo using 2 B channels. Telos also maintains an
identically configured test line in Freising, Germany at 49 81 61 42 061 (dial this number twice).
Terminal Adapter See TA
Tie Line See Tie Trunk.
Tie trunk A Trunk between two PBXs. Note, a tie line is a dedicated circuit, not a switched
circuit. See Trunk.
TR‐ 008 See SLC‐ 96
Trouble Ticket A Telco “work order” used to track Customer Repairs within the Telco. If you call
someone “inside” the Telco’s repair department, they will need this number to proceed. It will
also be needed whenever you call to check on the status of a repair. Always ask for this number
when initiating a repair request.
Trunk A communications path between two switching systems. Note that many trunks may be
on a single circuit (if that circuit has multiple channels). The trunks most users will deal with are
between the Telco switch and a PBX. However, a Tie Trunk can connect two PBXs. See also Tie
Trunk and Trunk Group
Trunk Group A number of telephone channels which are functionally related. Most common is
the Hunt Group. Other common types include Incoming Trunk Groups and Outgoing Trunk
Groups. See also Combination Trunks and Two‐ way DID Trunks.
Trunk Side 1) The side of a central office that faces the network. Historically many CO switches
could not make trunk to trunk connections (as opposed to tandem and long distance switches,
that are always used to connect trunk together). Hence the need to distinguish between the
"line side" and the "trunk side" of the switch. See also Line Side.
2) The side of a PBX that connects to the Telco. Historically many PBXs could not make trunk to
trunk connections. Hence the need to distinguish between the "line side" and the "trunk side" of
the switch. Since a trunk is a switch‐ to‐ switch circuit, these circuits can be called trunks.
Beware, even though you have a PBX, the Telco may still call these 'lines' (even though your PBX
considers them trunks). See also Trunk and Line Side
Two‐ way DID trunk An ISDN PRI equipped for direct inward dialing. Most PBX trunks are
related to a given phone number, either alone or as part of a hunt group. In the case of a
“normal” (i.e. analog) DID Trunk, a group of phone numbers are associated with that DID trunk
(or group of trunks) and incoming calls include the DID number, so the PBX can route that call to
the correct DID extension. These are one‐ way (i.e. inward only) trunks. This is exactly how ISDN
PRI functions, with the DID information coming in over the D channel. There is a big difference
between a normal DID Trunk and a Two‐ way DID trunk over ISDN PRI. For one thing, ISDN PRI is
digital. Another distinction is that you cannot dial out over a true DID trunk, while you can dial
out over a PRI (hence the conflicting designation "Two Way Direct Inward Dialing Trunk").
Two Wire A circuit path where only a single pair of wires is used. A hybrid is used to convert
from two wire to four wire circuits. No hybrid is perfect, and those used by the phone company
can be poor. However, the hybrids in Telos TWO/2101 family are approaching perfection!