(, ), ATM, :
(Constant Bit Rate, CBR), , ;
(Variable Bit Rate, VBR), ;
;
D .
SAR (Segmentation And Reassembly), . AAL1-AAL4, :
AL1 , (circuit-emulation), ( ). , . AAL1 , (, SONET/ SDH). SN (Sequence Number) SNP (Sequence Number Protection), . AAL1 .
AAL3/4 . ( D) . PDU (Protocol Data Unit), . , SAR (CRC-10), . CRC , ATM . , . SAR (, ), ( ) (multiplexing identifier), , .
AAL5 . , , I ATM (classical IP over ATM) LANE (LAN Emulation). : (trailer). 32- (CRC), . , 48 . 48- . . , : , .
|
|
AAL2 , , AAL1, AAL3/4 AAL5.
ATM , , . , . ATM , . (20 ) . , . 39. ID (Initial Domain Part) - DSP (Domain Specific Part). :
AFI (Authority and Format Identifier) : 39=DCC, 47=ICD, 45=E.164.
DCC (Data Country Code) .
H-DSP (High-Order Domain Specific Part) , . RD (Routing Domain) (AREA). , .
ESI (End System Identifier) , 48- -, IE.
SEL (Selector) , ( ).
ICD (International Code Designator) , .
.164 BISDN .164 ( ).
. 39. ATM: DCC ATM,
ICD ATM, NASP .164
, . , . ILMI (Interim Local Management Interface), UNI. , , ILMI, ( ).
ATM
ATM : - - . , . : (root node) (leaves). , . , . , , , AAL5 . AAL5 , .
|
|
(multicasting), AAL5, :
(VP multicasting) , (VP), VCI, . VCI, , , SAR-.
(multicast server) . , , , . , .
(overlaid point-to-multipomt connection). . ( , ). ( ) , . - . , , .