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•  Service provider identifier, which is acquired by the CPE from the DHCP server and sent to the 
ACS for selecting vender-specific configurations and parameters. For more information about 
CPE and ACS, see Network Management and Monitoring Configuration Guide. 
•  PXE server address, which is used to obtain the boot file or other control information from the 
PXE server. 
•  AC address, which is used by an AP to obtain the boot file or other control information from the 
AC. 
1.  Format of Option 43: 
Figure 19 Option 43 format 
 
 
Network configuration parameters are carried in different sub-options of Option 43 as shown 
in Figure 19. 
{  Sub-option type—The field value can be 0x01 (ACS parameter sub-option), 0x02 (service 
provider identifier sub-option), or 0x80 (PXE server address sub-option). 
{  Sub-option length—Excludes the sub-option type and sub-option length fields. 
{  Sub-option value—The value format varies by sub-option. 
2.  Sub-option value field formats: 
{  ACS parameter sub-option value field—Includes the ACS URL, username, and 
password separated by spaces (0x20) as shown in Figure 20. 
Figure 20
 ACS parameter sub-option value field 
 
 
{  Service provider identifier sub-option value field—Includes the service provider 
identifier. 
{  PXE server address sub-option value field—Includes the PXE server type that can only 
be 0, the server number that indicates the number of PXE servers contained in the 
sub-option, and server IP addresses, as shown in Figure 21. 
Figure 21 PXE ser
ver address sub-option value field