RADIUS attribute from rfc8045

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IP-Port-Ext-Port

The format of IP-Port-Ext-Port TLV is shown in Figure 10.  This
   attribute carries IPFIX Information Element 227,
   "postNAPTSourceTransportPort", which is the transport number
   associated with an external IPv4 address (refer to ).

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    TLV-Type   |     Length    |  postNAPTSourceTransportPort
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      postNAPTSourceTransportPort  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                                 Figure 10

   TLV-Type

      7

   Length

      Six octets

   postNAPTSourceTransportPort

      Integer.  This field contains the data (unsigned16) of
      postNAPTSourceTransportPort (227) defined in IPFIX, right
      justified, and unused bits MUST be set to zero.

   IP-Port-Ext-Port TLV MUST be included as part of the
   IP-Port-Forwarding-Map Attribute (refer to),
   identified as 241.7.7.

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