User's Manual

Configuration Guide of XGS-5240-Series
57-4
PPPoE length field (2 bytes): Specify the sum of all TLV length.
TLV type field (2 bytes): A TLV frame means a TAG, type field means TAG type, t
he table is as follows.
TLV length field (2 bytes): Specify the length of TAG data field.
TLV data field (the length is not specified): Specify the transmitted data of TAG.
Tag Type
Tag Explanation
0x0000 The end of a series tag in PPPoE data field, it is saved for ensuring the
version compatibility and is applied by some packets.
0x0101
Service name. Indicate the supplied services by network.
0x0102 Server name. When user receives the PADO response packet of AC, it ca
n obtain the server name from the tag and select the corresponding serve
r.
0x0103 Exclusive tag of the host. It is similar to tag field of PPPoE data packets
and is used to match the sending and reveiving end (Because broadcast
network may exist many PPPoE data packets synchronously).
0x0104
AC-Cookies. It is used to avoid the vicious DOS attack.
0x0105
The identifier of vendor.
0x0110 Relay session ID. PPPoE data packet can be interrupted to other AC, this
field is used to keep other connection.
0x0201 The error of service name. When the requested service name is not acce
pted by other end, the response packet will take this tag.
0x0202
The error of server name.
0x0203
Common error.
Table 13-1 TAG value type of PPPoE
1.1.1.27 PPPoE Intermediate Agent vendor tag Frame
The following is the format of tag added by PPPoE IA, adding tag is the Uppermo
st function of PPPoE IA.