Password Authentication Protocols (PAP)
PAP implements the traditional username and password authentication methods. At the request from an authenticator the client respond with both a PAP name and password in a single transaction. The authenticator validates this information and replies with a positive or negative acknowledgment. This acknowledgment can include readable text such as permission granted or access denied .
PAP is the simplest of the PAP authentication protocols available. User credentials are transmitted in plain text and only at beginning of a PPP session. All the advantages and disadvantages of PSP are identical to other dial up services secured with reusable usernames and passwords.
The PAP packet format side a PPP appears in the PPP frame protocols field is when it carries a PAP packet in its data padding fields. Any LCP negotiated change to the PPP frame format apply to frames that carry PAP. The PPP packet code field identifies the PPP message. The authentication request.
Packet include fields allocated for a username and password packets for authentication ack and authentication ank to authentication success and failure notifications. These packets have code values 0 x02 and 0x 03 respectively and include an explanatory text message area PPP software can use.