RADIUS attribute from rfc4679


IWF-Session

The presence of this Attribute indicates that the IWF has been
      performed with respect to the subscriber's session; note that no
      data field is necessary.  It MAY be included in both Access-
      Request and Accounting-Request packets.

   A summary of the IWF-Session Attribute format is shown below.  The
   fields are transmitted from left to right.

    0                   1
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Vendor-Type  | Vendor-Length |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Vendor-Type

      254 (0xFE) for IWF-Session

   Vendor-Length

      24.  Table of AttributesThe following table provides a guide to which attributes may be found
   in which kinds of packets, and in what quantity; note that since none
   of the DSL Forum VSAs may be present in the Access-Accept, Access-
   Reject or Access-Challenge packets, those columns have been omitted
   from the table.

   Request   Acct-Request  #   Attribute
   0-1       0-1            1  Agent-Circuit-Id
   0-1       0-1            2  Agent-Remote-Id
   0-1       0-1          129  Actual-Data-Rate-Upstream
   0-1       0-1          130  Actual-Data-Rate-Downstream
   0         0-1          131  Minimum-Data-Rate-Upstream
   0         0-1          132  Minimum-Data-Rate-Downstream
   0         0-1          133  Attainable-Data-Rate-Upstream
   0         0-1          134  Attainable-Data-Rate-Downstream
   0         0-1          135  Maximum-Data-Rate-Upstream
   0         0-1          136  Maximum-Data-Rate-Downstream
   0         0-1          137  Minimum-Data-Rate-Upstream-Low-Power
   0         0-1          138  Minimum-Data-Rate-Downstream-Low-Power
   0         0-1          139  Maximum-Interleaving-Delay-Upstream
   0         0-1          140  Actual-Interleaving-Delay-Upstream
   0         0-1          141  Maximum-Interleaving-Delay-Downstream
   0         0-1          142  Actual-Interleaving-Delay-Downstream
   0-1       0-1          144  Access-Loop-Encapsulation
   0-1       0-1          254  IWF-Session

   The following table defines the meaning of the above table entries.

   0      This Attribute MUST NOT be present in packet.

   0-1    Zero or one instances of this Attribute MAY be present in
          packet.5.  Security ConsiderationsThe security of these Attributes relies on an implied trust
   relationship between the Access Node/DSLAM and the BRAS.  The
   identifiers that are inserted by the Access Node/DSLAM are
   unconditionally trusted; the BRAS does not perform any validity check
   on the information received.  These Attributes are intended to be
   used in environments in which the network infrastructure (the Access
   Node/DSLAM, the BRAS, and the entire network in which those two
   devices reside) is trusted and secure.As used in this document, the word "trusted" implies that
   unauthorized traffic cannot enter the network except through secured
   and trusted devices and that all devices internal to the network are
   secure and trusted.  Careful consideration should be given to the
   potential security vulnerabilities that are present in this model
   before deploying this option in actual networks.

   The Attributes described in this document neither increase nor
   decrease the security of the RADIUS protocol.  For discussions of
   various RADIUS vulnerabilities, see , , ,
   and .6.  References