DSLAM (Digital Subscriber Line Access Multiplexer)

In digital subscriber line (DSL) networks,

a packet multiplexer that provides the interface between the DSL local loop and the service provider’s point of presence (POP). Most DSLAMs are ATM-based, although some earlier models are based on frame relay, with the specific technology depending on what the carrier has in place. In an ADSL scenario the DSLAM receives upstream DSL traffic and splits, or demultiplexes, the voice and data traffic. The voice traffic then is encoded into pulse code modulation (PCM) format and time division multiplexed over a channelized T1,T3, or, perhaps, SONET link to the public switched telephone network (PSTN).The data traffic is multiplexed or concentrated in asynchronous transfer mode (ATM) cells over an unchannelized T1, T3, or SONET circuit directly to the Internet backbone, or to perhaps to an independent Internet service provider (ISP). The DSLAM generally represents the first potential point of contention and congestion that affects upstream end user traffic, as the local loop is a dedicated circuit. In asymmetric DSL

(ADSL) implementations, the line side of the DSLAM in known as an ADSL transmission unit-centralized (ATU-C). See also ADSL, ATM, ATU-C, carrier, DSL, ISP, line side, PCM, POP, SONET, T1, T3, and upstream.

• 16
• 16-QAM
• 16-QPSK
• 18
• 1:8 Splitter
• 1A
• 1A1
• 1A2
• 1Base5 (1 Mbps; Baseband; 500 meters)
• 1B+D
• 1. Domain Name System. The naming convention that divides the Internet into logical domains identified in Internet Protocol version 4 (IPv4) as a 32-bit portion of the total address.The standard convention is user@organization.domain, where user is the name of the end user, organization is the name of the enterprise or other organization owning or sponsoring the address, and domain is the type of entity owning or sponsoring the address.The administration of the DNS is the responsibility of Internet Corporation for Assigned Names and Numbers (ICANN). See also domain, ICANN, Internet, and IPv4. 2.
• 1. In storage, irrelevant material, usually zero (0) bits, added to a data block in order to fill it to a minimum size, to force certain fields of control data or user data into certain positions or sizes, or to prevent the user data from duplicating a bit pattern that has a specific control meaning. See also block. 2.
• 1 cps, 1 Hz
• 1+ Dialing
• 1G (1st Generation)
• 1G (1st Generation)
• 1-persistent carrier sense multiple access (1-Persistent CSMA)
• 1-Persistent CSMA (1-Persistent Carrier Sense Multiple Access)
• 1+ WATS
• 1xEV-DO (one carrier EVolution-Data Optimized)
• 1xRTT (one times Radio Transmission Technology)
• 2
• 20
• 2:1
• 2:1