ZyXEL Communications GS1920v2 Series User Manual page 250

This tag is defined in RFC 2516 and has the following format for this feature.
Table 126 PPPoE Intermediate Agent Vendor-specific Tag Format
Tag_Type
(0x0105)
The Tag_Type is 0x0105 for vendor-specific tags, as defined in RFC 2516. The Tag_Len indicates the
length of Value, i1 and i2. The Value is the 32-bit number 0x00000DE9, which stands for the "ADSL Forum"
IANA entry. i1 and i2 are PPPoE intermediate agent sub-options, which contain additional information
about the PPPoE client.
41.1.2.2 Sub-Option Format
There are two types of sub-option: "Agent Circuit ID Sub-option" and "Agent Remote ID Sub-option".
They have the following formats.
Table 127 PPPoE IA Circuit ID Sub-option Format: User-defined String
SubOpt
0x01
(1 byte)
Table 128 PPPoE IA Remote ID Sub-option Format
SubOpt
0x02
(1 byte)
The 1 in the first field identifies this as an Agent Circuit ID sub-option and 2 identifies this as an Agent
Remote ID sub-option. The next field specifies the length of the field. The Switch takes the Circuit ID string
you manually configure for a VLAN on a port as the highest priority and the Circuit ID string for a port as
the second priority. In addition, the Switch puts the PPPoE client's MAC address into the Agent Remote
ID Sub-option if you do not specify any user-defined string.
Flexible Circuit ID Syntax with Identifier String and Variables
If you do not configure a Circuit ID string for a VLAN on a specific port or for a specific port, the Switch
adds the user-defined identifier string and variables into the Agent Circuit ID Sub-option. The variables
can be the slot ID of the PPPoE client, the port number of the PPPoE client and/or the VLAN ID on the
PPPoE packet.
The identifier-string, slot ID, port number and VLAN ID are separated from each other by a pound key
(#), semi-colon (;), period (.), comma (,), forward slash (/) or space. An Agent Circuit ID Sub-option
example is "Switch/07/0123" and indicates the PPPoE packets come from a PPPoE client which is
connected to the Switch's port 7 and belong to VLAN 123.
Table 129 PPPoE IA Circuit ID Sub-option Format: Using Identifier String and Variables
SubOpt Length
0x01 N
(1 byte) (1 byte)
Tag_Len
Length
N String
(1 byte) (63 bytes)
Length
N MAC Address or String
(1 byte) (63 bytes)
Identifier delimiter
String
(1 byte)
(53 byte)
GS1920v2 Series User's Guide
Chapter 41 PPPoE
Value i1
Value
Value
Value
Slot ID delimiter
(1 byte) (1 byte)
250
i2
Port No delimiter VLAN ID
(2 byte) (1 byte) (4
bytes)