RADIUS attribute from rfc7268


Network-Id-Name

The Network-Id-Name Attribute is utilized by implementations of
      IEEE-802.1X  to specify the name of a Network-Id
      (NID-Name).

      Unlike the IEEE 802.11 SSID (which is a maximum of 32 octets in
      length), the NID-Name may be up to 253 octets in length.
      Consequently, if the MAC address is included within the Called-
      Station-Id Attribute, it is possible that there will not be enough
      remaining space to encode the NID-Name as well.  Therefore, when
      used with IEEE 802.1X , the Called-Station-Id
      Attribute SHOULD contain only the MAC address, with the Network-
      Id-Name Attribute used to transmit the NID-Name.  The Network-Id-
      Name Attribute MUST NOT be used to encode the IEEE 802.11 SSID; as
      noted in , the Called-Station-Id Attribute is used for
      this purpose.Zero or one Network-Id-Name Attribute is permitted within an
      Access-Request, Access-Challenge, Access-Accept or Accounting-
      Request packet.  When included within an Access-Request packet,
      the Network-Id-Name Attribute represents a hint of the NID-Name to
      which the Supplicant should be granted access.  When included
      within an Access-Accept packet, the Network-Id-Name Attribute
      represents the NID-Name to which the Supplicant is to be granted
      access.  When included within an Accounting-Request packet, the
      Network-Id-Name Attribute represents the NID-Name to which the
      Supplicant has been granted access.

      A summary of the Network-Id-Name Attribute format is shown below.
      The fields are transmitted from left to right.

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

   Type

      179

   Length

      >=3

   String

      The String field is one or more octets, containing a NID-Name.
      For details, see .  A robust implementation SHOULD
      support the field as undistinguished octets.