Even experts need occasional help with telecom terms. We have combined glossaries from several sources to simplify finding the definitions you need.
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HDSL Compatible Unbundled Loop 2 Wire A Verizon Wholesale Unbundled Loop service offering that consists of a loop facility extending from the Central Office Distribution Frame (MDF) to the End User Customer Premises Network Interface Device that is compatible with HDSL technology. Learn more.
HDSL Compatible Unbundled Loop 4 Wire A Verizon Wholesale Unbundled Loop service offering that consists of a loop facility extending from the Central Office Distribution Frame (MDF) to the End User Customer Premises Network Interface Device that is compatible with HDSL technology. Learn more.
Routing based on a hierarchical addressing system. IP routing algorithms use IP addresses, for example, which contain network numbers, host numbers, and frequently, subnet numbers.
High-Bit Rate Digital Subscriber Line (HDSL)
A transmission technology that transmits over two twisted cable pairs up to a DS1-level signal, using any one of the following line codes: Binary / 1 Quaternary (2B1Q) Carrierless AM/PM, Discrete Multitone ("DMT"), or Binary / 1 Octel ("3BO").
High Capacity Access Service Request
An order for a stated amount of capacity/equipment (to be built or reserved) that specifies certain obligations on the part of the telephone company and the Interexchange Carrier. Learn more.
A two-point digital channel, which provides for simultaneous two-way transmission of serial, bipolar, return-to-zero, isochronous digital signals at a transmission speed of 1.544 megabits per second.
High Capacity Switched Access Transport
Dedicated transport service that sends large volumes of voice and/or data at 1.544 Megabits per second or higher. Also known as High Capacity Service.
High Speed Data (HSD)
interface normally using V.35 or EIA53 standards.
High Speed Serial Interface (HSSI)
Standard for a serial interface at high speeds (64 Kbps and higher up to 52 Mbps) between DTE and DCE equipment over very short distances. Used for a physical connection between a router and a DSU.
Near-simultaneous disconnection of a Verizon working loop from a port on one carrier's switch, and the reconnection of that loop to a port on a different carrier's switch, without any significant out-of-service period. Learn more.
House & Riser
A Verizon Wholesale Interconnection Service that provides a CLEC with access to facilities between the network side of the network interface of the CLEC's end user and a point of interconnection on the same premises where Verizon's subscriber facility and House & Riser facilities terminate. Learn more.
See High Speed Data.
See High Speed Serial Interface.
The point on a network where several circuits are connected; also, a network switching node.
Hundred Call Seconds
A telephone traffic engineering unit of measurement equaling one hundred (100) seconds of usage.