RADIUS packets, whether requests or responses, always include a type. These
   constants are provided to make it easier to specify types when using
   radius_create_request and when comparing the result of
   radius_send_request.
  
  
   
    - 
     RADIUS_ACCESS_REQUEST(integer)
- 
     
      An Access-Request, used to authenticate a user against a RADIUS server.
      Access request packets must include a
      RADIUS_NAS_IP_ADDRESSor aRADIUS_NAS_IDENTIFIERattribute, must also include aRADIUS_USER_PASSWORD,RADIUS_CHAP_PASSWORDor aRADIUS_STATEattribute, and should include aRADIUS_USER_NAMEattribute.
 
- 
     RADIUS_ACCESS_ACCEPT(integer)
- 
     
      An Access-Accept response to an Access-Request indicating that the
      RADIUS server authenticated the user successfully.
      
- 
     RADIUS_ACCESS_REJECT(integer)
- 
     
      An Access-Reject response to an Access-Request indicating that the
      RADIUS server could not authenticate the user.
      
- 
     RADIUS_ACCESS_CHALLENGE(integer)
- 
     
      An Access-Challenge response to an Access-Request indicating that the
      RADIUS server requires further information in another Access-Request
      before authenticating the user.
      
- 
     RADIUS_ACCOUNTING_REQUEST(integer)
- 
     
      An Accounting-Request, used to convey accounting information for a
      service to the RADIUS server.
      
- 
     RADIUS_ACCOUNTING_RESPONSE(integer)
- 
     
      An Accounting-Response response to an Accounting-Request.
      
- 
     RADIUS_COA_REQUEST(integer)
- 
     
      A CoA-Request, sent from the RADIUS server to indicate that the
      authorisations within the user session have changed. A response must be
      sent in the form of a CoA-ACK or a CoA-NAK.
      
      This constant is available in PECL radius 1.3.0 and later.
      
- 
     RADIUS_COA_ACK(integer)
- 
     
      A CoA-ACK, sent to the RADIUS server to indicate that the user
      authorisations have been updated.
      
      This constant is available in PECL radius 1.3.0 and later.
      
- 
     RADIUS_COA_NAK(integer)
- 
     
      A CoA-NAK, sent to the RADIUS server to indicate that the user
      authorisations could not be updated.
      
      This constant is available in PECL radius 1.3.0 and later.
      
- 
     RADIUS_DISCONNECT_REQUEST(integer)
- 
     
      A Disconnect-Request, sent from the RADIUS server to indicate that the
      user session must be terminated.
      
      This constant is available in PECL radius 1.3.0 and later.
      
- 
     RADIUS_DISCONNECT_ACK(integer)
- 
     
      A Disconnect-ACK, sent to the RADIUS server to indicate that the user
      session has been terminated.
      
      This constant is available in PECL radius 1.3.0 and later.
      
- 
     RADIUS_DISCONNECT_NAK(integer)
- 
     
      A Disconnect-NAK, sent to the RADIUS server to indicate that the user
      session could not be terminated.
      
      This constant is available in PECL radius 1.3.0 and later.