Interphase-tech iSPAN Manual de usuario descargar pdf (Pagina 219)

iSPAN Serial WAN Adapter Users Guide 199

(ANSI) Standard T1.618 and the International Telegraph and Tele-

phone Consultative Committee (CCITT) Standard Q.922, indicates the

functions associated with certain DLCI values:

DCD (Data Carrier Detect) ◆ See CD (Carrier Detect).

DCE (Data Communications Equipment, Data Circuit-Terminating

Equipment)

◆ Equipment that provides the functions required to

establish, maintain, and terminate a connection (including signal con-

version) for communications between the data terminal equipment and

the telephone line or data circuit. Also, interface signals typically pre-

sented by this equipment.

D Channel ◆ Standard channel on an ISDN PRI or BRI line. At 16

Kbps, a D channel carries all signalling information and can carry low-

speed packet data such as X.25 packet switching.

DE ◆ See Discard Eligibility (DE).

Demarc (Demarcation Point) ◆ The point on a customer's premises

where the line from the telephone company meets the customer's wir-

ing at the customer's premises.

DFT ◆ See Distributed Function Terminal (DFT).

Directory Number ◆ Your seven-digit telephone number (without the

area code), as found in the telephone directory. Each BRI connection

can have up to two Directory Numbers, one for each B channel.

Discard Eligibility (DE) ◆ A bit indicating that a frame may be dis-

carded in preference to other frames if congestion occurs to maintain

the committed information rate. See also Excess Burst Size and CIR.

DLCI Values Function

0 In-channel signalling

1-15 Reserved

16-991 Assigned using frame-relay connection procedures

992-1007 Layer 2 management of frame-relay bearer service

1008-1022 Reserved

1023 In-channel layer management

1 2 ... 214 215 216 217 218 219 220 221 222 223 224 ... 235 236

Sin comentarios

Interphase-tech iSPAN Manual de usuario Pagina 219