Were you disgusted at ATM adaptation layer?

Well, the material of the study of today's chief telecommunications engineer is an ATM, too. The ATM and the adaptation layer call AAL for short today. AAL is a layer that hits the sub-layer in OSI reference model's data link layer. When you allow me to quote the explanation of the type of AAL from Wiki easily

AAL1 connection type and constant bit rate. Standard for communication of mass animation such as video conferencing telephones. To use one octet of payloads for the control of the order of transmitting the cell, real data becomes 47 octets. It is used in premises LAN.

AAL2 connection type and variable bit rate. Standard for low-speed voice sign. It is allowed to multiplex two or more traffic to one cell to decrease jitter's (swing the delay) influence by assembly and the restoration of the cell, and to send before the cell is filled.

AAL3/4 connectionless type and constant bit rate. Standard for for data communication. AAL3 and AAL4 were integrated by moving the connection setting to a high-ranking layer though it originally proposed AAL3 as a connection type and AAL4 was proposed as a connectionless type. To use four octets of payloads for high-ranking layer PDU information, real data becomes 44 octets.

AAL5 connectionless type and variable bit rate. Standard by which AAL3/4 is simplified. All payloads can be used for real data by assuming a positional detecting function of a high-ranking layer to be only a finality part. It is widely used as large area LAN with Ethernet over ATM, IP over ATM, and PPPoA (Point-to-Point Protocol over ATM). ･･･. It is so. Then, it is based and today's material is [kochira] ↓↓.




- ATM adaptation layer (AAL)



The leased circuit service etc. are used to communicate on the ATM network being classified into service class A pseudo.. resemblance of existing line service for the communication of the fixed speed type. AAL type 1

These sentences are correct.
- AAL type 1 It communicates like the leased circuit service etc. on the ATM network being classified into service class A for the communication = fixed speed type by pseudo.. resemblance of existing line service.



AAL type 2 is used to communicate of the real time character's at a changeable speed not being demanded ..for a low-speed voice-data communication...

These sentences are wrong.
- AAL type 2 is for a low-speed voice-data communication, and real time AAL for the communication from which the character is demanded at a changeable speed.
- Type 2 is low-speed though type 1 is a fixed speed at a changeable speed ･･･ However, the character is in real time demanded naturally because it uses it for the voice-data communication.




AAL type 3/4 is hardly used from becoming of AAL type 5 with few overheads or more the main current for the data communication for the data communication.

These sentences are correct.
- The AAL type is hardly used from becoming of AAL type 5 with few overheads or more the main current for the data communication for 3/4= data communication.



Isn't today's problem comparatively comprehensible?However, correct sentences that become livers of the layer, changing sentences for a moment in the part like "Extra", and setting questions do doing by being ･･･ Then, around here today