Csma/Cd

Glossary

central office (CO)

In telephony, the phone company switching facility or center, usually a Class 5 end office, at which subscribers local loops terminate. Handles a specific geographic area, identified by the first three digits of the local telephone num- ber. Usually the facilities of the local BOC.

Carrier Sense Multiple Access Collision Detect. A channel access mechanism where devices check the channel for a carrier before transmitting. If no carrier is sensed for the specified period of time, the device can transmit. If two de- vices transmit at once, a collision occurs and is detected by all colliding devic- es. This collision subsequently delays their retransmissions for a random length of time. CSMA/CD is used by Ethernet and IEEE 802.3.

D-channel

The ISDN channel that carriers signalling information to control the call setup, teardown, or invocation of supplementary services. The D-Channel may also be used to provide packet mode data service.

DDS

Dataphone Digital Service. AT&T private line service for transmitting data over a digital system. The digital transmission system transmits electrical sig- nals directly, instead of translating the signals into tones of varied frequencies as with traditional analog transmission systems. Digital techniques provide more efficient use of transmission facilities, resulting in lower error rates and costs than analog systems.

digital hub

Designated office where DDS channels are interconnected and where synchro- nous network timing, testing access, and additional service features are pro- vided.

Ethernet

A local area network used for connecting computers, printers, workstations, a terminals, servers, etc., within the same building or campus. Ethernet operates over twisted wire and coaxial cable at speeds up to 10 Mbps. Ethernet speci- fies a CSMA/CD.

four-wire circuits

Telephone lines using two wires for transmitting and two wires for receiving, offering much higher quality than a 2-wire circuit. All long distance circuits are 4-wire. Almost all local phone lines and analog phones are 2-wire.

group 4

A high-speed (56 kbps) facsimile protocol specific to ISDN.

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Express XL/XLT User Manual

61200070L1-1

Express XLT, Express XL specifications

ADTRAN has established itself as a leading provider of telecommunications solutions, and among its impressive lineup, the ADTRAN Express XL and Express XLT stand out as robust offerings designed for the evolving demands of modern networks. These devices cater to service providers and enterprises looking to enhance their broadband delivery capabilities while ensuring cost-efficiency and reliability.

The ADTRAN Express XL is a high-capacity, next-generation fiber optic access platform. It is engineered to support a wide array of technologies, including Passive Optical Network (PON) standards such as GPON and XGSPON. The Express XL's architecture allows for seamless scalability, making it a perfect fit for both small-scale deployments and expansive network rollouts. What sets it apart is its ability to deliver ultra-fast broadband services to residential, business, and mobile backhaul customers with its impressive throughput capabilities.

On the other hand, the Express XLT builds upon the success of the Express XL by incorporating advanced features aimed at maximizing operational efficiency. It supports technologies including Active Ethernet and offers flexible network configurations to meet specific service requirements. Both models utilize ADTRAN’s innovative Dynamic Bandwidth Allocation technology, which dynamically allocates bandwidth to users based on real-time demand, ensuring optimal performance and user satisfaction.

A key characteristic of both ADTRAN Express XL and XLT is their energy efficiency. Designed to minimize operational costs, these units use power-saving technologies that reduce energy consumption without compromising performance. Furthermore, they include built-in support for network functions virtualization (NFV) and software-defined networking (SDN), providing operators with the agility to adapt their networks in response to changing market conditions.

In addition to their advanced technological underpinnings, the Express XL and XLT boast an intuitive management interface, simplifying network monitoring and management tasks. They also feature comprehensive telemetry and analytics capabilities that help operators gain insights into network performance, optimize configurations, and troubleshoot potential issues before they affect end users.

Ultimately, the ADTRAN Express XL and Express XLT are pivotal components for service providers aiming to deliver high-speed broadband services effectively. With their blend of flexibility, scalability, and energy efficiency, these access platforms are well-positioned to meet the current and future demands of telecommunications networks worldwide.

ADTRAN Express XLT user manual Csma/Cd

Models: Express XLT Express XL