User Manual
Table 3-1 LLC Format
The table 3-1 is the format of LLC PDU. It comprises four fields, DSAP, SSAP, Control and Information. The DSAP address field identifies the one or more service access points, in which the I/G bit indicates it is individual or group address. If all bit of DSAP is 1s, it’s a global address. The SSAP address field identifies the specific services indicated by C/R bit (command or response). The DSAP and SSAP pair with some reserved values indicates some well-known services listed in the table below.
0xAAAA | SNAP |
0xE0E0 | Novell IPX |
0xF0F0 | NetBios |
0xFEFE | IOS network layer PDU |
0xFFFF | Novell IPX 802.3 RAW packet |
0x4242 | STP BPDU |
0x0606 | IP |
0x9898 | ARP |
Table 3-2
LLC type 1 connectionless service, LLC type 2 connection-oriented service and LLC type 3 acknowledge connectionless service are three types of LLC frame for all classes of service. In Fig 3-2, it shows the format of Service Access Point (SAP). Please refer to IEEE802.2 for more details.
Publication date: March, 2007
Revision A1
