TP-Link T2600G-28TS User Manual page 295

PPPoE ID-Insertion Operation Process
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The PPPoE ID insertion includes Circuit-ID tag and Remote-ID tag. The following process takes
Circuit-ID insertion as an example:
The PPPoE discovery process is illustrated below:
1. The client sends PADI (PPPoE Active Discovery Initiation) packets to the switch.
2. The switch intercepts PADI packets and inserts a unique Circuit-ID tag to them.
3. The switch forwards the PADI packets with Circuit-ID tag to the BRAS.
4. The BRAS responses with the PADO (PPPoE Active Discovery Offer) packets after receiving
the PADI packets.
5. Upon receiving the PADO packets with the Circuit-ID tag, the switch will remove the tag and
send the packets to the client. The switch will forward the PADO packets without the Circuit-ID
tag directly.
6. The client sends PADR (PPPoE Active Discovery Request) packets according to the process.
7. The switch intercepts PADR packets and inserts a unique Circuit-ID tag to them.
8. The switch forwards the PADR packets with Circuit-ID tag to the BRAS.
9. The BRAS processes the received Circuit-ID tag in the PADR packets and extracts the
Circuit-ID field to the RADIUS for accounting. And the BRAS allocates a PPP process session
ID for this PPP session.
10. The BRAS responses with the PADS (PPPoE Active Discovery Session-confirmation) packets
after receiving the PADR packets.
11. Upon receiving the PADS packets with the Circuit-ID tag, the switch will remove the tag and
send the packets to the client. The switch will forward the PADS packets without the Circuit-ID
tag directly.
On the PPPoE ID Insertion page, you can enable the PPPoE ID insertion function globally. Each
port's PPPoE ID Insertion feature and type can be configured separately.
PPPoE Discovery Process
Figure 13-1
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