A network of multiple interconnected data terminals or devices
within a local area to facilitate data transfer. Most notable of LAN
topologies are ethernet, token ring, and FDDI.
LAN Interconnect
A point on a LAN where circuits can be routed & administered.
LAP - Local Access Provider
LAT - Local Area Transport.
Ethernet protocol developed by Digital Equipment Corporation.
LATA
Local Access Transport Areas (200 in the U.S.). A geographic
service area defined in the AT&T Modified Final Judgement. The RBOCs (baby Bells) and GTE are restricted to operations
within, but not between, LATAs. Long distance service within a LATA
is provided by the LEC.
Service between LATAs is provided by an IEC.
LATAs are represented by a 3-character code.
Layers
System design and communication standards that define
different levels of conceptual abstraction (simplification). (e.g.
The ISO OSI framework consists of seven layers.)
Layer 1
Physical Layer - The equipment
Layer 2
Data Link Layer - Protocols
& Error Messages
Layer 3
Network Layer - Addresses & Routing
Layer 4
Transport Layer - Information Exchange - Delivery & Flow
Fractional digital service hierarchy level 1 with service much the
same as FT-1 except the service is integrated with voice, data, video,
and frame relay.
LEC - See Local Exchange
Carrier
LEC BAN - Billing Account
Number
3-digit number appended to the billing phone number used as
the LEC customer
number. Groups all
ANIs for a customer.
LEC Billing
Arrangement whereby the
Local Exchange Carrier invoices the customer for some or all
telecommunications services.
LEC Card
The billing arrangement which enables the caller to bill calls to
an authorized calling card issued by a
local exchange carrier.
An electronic device that efficiently emits light with little
generation of heat. LEDs are often used in fiber-optic systems
instead of coherent light lasers, particularly when low speeds or
short distances are involved.
LERG - Local Exchange Routing
Guide
Documents end offices and their relationship to Tandem (Class 4 Toll)
Offices. Produced by Bellcore Traffic Routing Admin (TRA).
A document that authorizes changing the service provider.
(See RespOrg,
800 Portability)
Line Number
The 4-digit XXXX number assigned to a North American
telephone within an NXX exchange. (See
NANP)
Line Segment
The expanse of fiber-optic cable(s) between 2 network locations.
LMI - Local Management Interface
A protocol with four different versions used to control the local
interface from a routing device to the WAN Switch. Also used for
configuration, flow control, and maintenance of the local connection.
LNS
Abbreviation for Lines, "#LNS" is the number of lines
Local Loop. The connection from a subscriber to the Central Office. The portion of a circuit connecting the LEC's CO with the
customer's premise equipment across the local network.
Local Access Mileage
For dedicated (non-switched) private
lines there may be a recurring charge rate element that is
based on mileage to the
Central Office.
Local Access Provider
Any organization that is authorized to provide local access.
(May or may not be the LEC.)
Local Exchange
Carrier - LEC
The local or regional telephone company that owns and operates
lines to customer locations and Class 5Central Office Switches.
LECs have connections to other COs, Tandem
(Class 4 Toll) offices and may
connect directly to IECs like LDDS WorldCom, AT&T,
MCI, Sprint, etc.
A company providing long-distance phone service between LECs and LATAs.
Long Distance
Marketplace
The long distance voice and data market is over $60 billion
per year. AT&T provides more than half, with MCI, Sprint, and
LDDS in the second, third and forth place positions.
A circuit test at any device which will tie the transmit data to
the receive data in order to apply a signal and receive the data back
for interpretation. Usually done at a customer device such as a CSU or a
network device such as DS-O or DS-1 DACS port.
