QTECH QSW-3400 Инструкция по настройке - Manual (Page 376)

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PPPoE IA protocol exchange process
49.1.2.2 PPPoE Packet Format
PPPoE packet format is as follows:
Ethernet II frame
Destination
MAC
Source MAC Type Field PPPoE Data CRC Check
Sum
PPPoE data
Version Type Code Session
ID
Length Field TLV1 …… TLV N
TLV frame
Type Length Data
Each field meanings in the following:
Type field (2 bytes) of Ethernet II frame: The protocol sets type field value of PPPoE protocol
packet as 0x8863 (include 5 kinds of packets in PPPoE discovery stage only), type field value
of session stage as 0x8864.
PPPoE version field (4 bits): Specify the current PPPoE protocol version, the current version
must be set as 0x1.
PPPoE type field (4 bits): Specify the protocol type, the current version must be set as 0x1.
PPPoE code field (1 byte): Specify the packet type. 0x09 means PADI packet, 0x07 means
PADO packet, 0x19 means PADR packet, 0x65 means PADS packet, 0xa7 means PADT
packet.
PPPoE session ID field (2 bytes): Specify the session ID.
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, the 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 can
obtain the server name from the tag and select the corresponding server.
0x0103 Exclusive tag of the host. It is similar to tag field of PPPoE data packets and is