Zhone 5100 Guia Da Instalação

APPENDIX D

   

AL —ATM Adaptation Layer. Service-dependent sublayer of the data link layer. The AAL accepts 

data from different applications and presents it to the ATM layer in the form of 48-byte ATM 

payload segments. AALs consist of two sublayers: convergence sublayer (CS) and segmentation 

and reassembly (SAR). AALs differ on the basis of the source-destination timing used, whether 

they use constant bit rate (CBR) or variable bit rate (VBR), and whether they are used for 

connection-oriented or connection less mode data transfer. At present, the four types of AAL 

recommended by the ITU-T are AAL1, AAL2, AAL3/4, and AAL5. 
AAL1—ATM adaptation layer 1. One of four AALs recommended by the ITU-T. AAL1 is used for 

connection-oriented, delay-sensitive services requiring constant bit rates, such as uncompressed 

video and other isochronous traffic.
AMI—alternate mark inversion. Line-code type used on T1 and E1 circuits. In AMI, zeros are 

represented by 01 during each bit cell, and ones are represented by 11 or 00, alternately, during 

each bit cell. AMI requires that the sending device maintain ones density. Ones density is not 

maintained independent of the data stream. Sometimes called binary coded alternate mark 

inversion. 
ATM—Asynchronous Transfer Mode. International standard for cell relay in which multiple 

service types (such as voice, video, or data) are conveyed in fixed-length (53-byte) cells. Fixed-

length cells allow cell processing to occur in hardware, thereby reducing transit delays. ATM is 

designed to take advantage of high-speed transmission media such as E3, SONET, and T3.
ATPM— Address Translation Parsing Module..
Application Service Providers (ASPs). Third-party entities that manage and distribute software-

based services and solutions to customers across a wide-area network from a central data center.
B8ZS—binary 8-zero substitution. Line-code type, used on T1 and E1 circuits, in which a special 

code is substituted whenever 8 consecutive zeros are sent over the link. This code is then 

interpreted at the remote end of the connection. This technique guarantees ones density 

independent of the data stream.
CAS—channel-associated signaling. Trunk signaling (for example, in a T1 line) in which control 

signals, such as those for synchronizing and bounding frames, are carried in the same channel 

along with voice and data signals. 
CBR—constant bit rate. QoS class defined by the ATM Forum for ATM networks. CBR is used 

for connections that depend on precise clocking to ensure undistorted delivery.
CCS—common channel signaling. Trunk signaling (for example, using Primary Rate Interface) in 

which a control channel carries signaling for separate voice and data channels. 
CES—circuit emulation service. Enables users to multiplex or concentrate multiple circuit 

emulation streams for voice and video with packet data on a single high-speed ATM link without 

a separate ATM access multiplexer.
CLI— Command Line Interface.
CMCP— Copper Mountain Control Protocol.
CMTN—Copper Mountain.