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RFC 5415

 
 
 

Control And Provisioning of Wireless Access Points (CAPWAP) Protocol Specification

Part 4 of 6, p. 68 to 103
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4.6.9.  CAPWAP Control IPv4 Address

   The CAPWAP Control IPv4 Address message element is sent by the AC to
   the WTP during the Discovery process and is used by the AC to provide
   the interfaces available on the AC, and the current number of WTPs
   connected.  When multiple CAPWAP Control IPV4 Address message
   elements are returned, the WTP SHOULD perform load balancing across
   the multiple interfaces (see Section 6.1).

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |           WTP Count           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   10 for CAPWAP Control IPv4 Address

   Length:   6

   IP Address:   The IP address of an interface.

   WTP Count:   The number of WTPs currently connected to the interface,
      with a maximum value of 65535.

4.6.10.  CAPWAP Control IPv6 Address

   The CAPWAP Control IPv6 Address message element is sent by the AC to
   the WTP during the Discovery process and is used by the AC to provide
   the interfaces available on the AC, and the current number of WTPs
   connected.  This message element is useful for the WTP to perform
   load balancing across multiple interfaces (see Section 6.1).

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |           WTP Count           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

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   Type:   11 for CAPWAP Control IPv6 Address

   Length:   18

   IP Address:   The IP address of an interface.

   WTP Count:   The number of WTPs currently connected to the interface,
      with a maximum value of 65535.

4.6.11.  CAPWAP Local IPv4 Address

   The CAPWAP Local IPv4 Address message element is sent by either the
   WTP, in the Join Request, or by the AC, in the Join Response.  The
   CAPWAP Local IPv4 Address message element is used to communicate the
   IP Address of the transmitter.  The receiver uses this to determine
   whether a middlebox exists between the two peers, by comparing the
   source IP address of the packet against the value of the message
   element.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   30 for CAPWAP Local IPv4 Address

   Length:   4

   IP Address:   The IP address of the sender.

4.6.12.  CAPWAP Local IPv6 Address

   The CAPWAP Local IPv6 Address message element is sent by either the
   WTP, in the Join Request, or by the AC, in the Join Response.  The
   CAPWAP Local IPv6 Address message element is used to communicate the
   IP Address of the transmitter.  The receiver uses this to determine
   whether a middlebox exists between the two peers, by comparing the
   source IP address of the packet against the value of the message
   element.

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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           IP Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   50 for CAPWAP Local IPv6 Address

   Length:   16

   IP Address:   The IP address of the sender.

4.6.13.  CAPWAP Timers

   The CAPWAP Timers message element is used by an AC to configure
   CAPWAP timers on a WTP.

      0                   1
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Discovery   | Echo Request  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   12 for CAPWAP Timers

   Length:   2

   Discovery:   The number of seconds between CAPWAP Discovery messages,
      when the WTP is in the Discovery phase.  This value is used to
      configure the MaxDiscoveryInterval timer (see Section 4.7.10).

   Echo Request:   The number of seconds between WTP Echo Request CAPWAP
      messages.  This value is used to configure the EchoInterval timer
      (see Section 4.7.7).  The AC sets its EchoInterval timer to this
      value, plus the maximum retransmission time as described in
      Section 4.5.3.

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4.6.14.  CAPWAP Transport Protocol

   When CAPWAP is run over IPv6, the UDP-Lite or UDP transports MAY be
   used (see Section 3).  The CAPWAP IPv6 Transport Protocol message
   element is used by either the WTP or the AC to signal which transport
   protocol is to be used for the CAPWAP data channel.

   Upon receiving the Join Request, the AC MAY set the CAPWAP Transport
   Protocol to UDP-Lite in the Join Response message if the CAPWAP
   message was received over IPv6, and the CAPWAP Local IPv6 Address
   message element (see Section 4.6.12) is present and no middlebox was
   detected (see Section 11).

   Upon receiving the Join Response, the WTP MAY set the CAPWAP
   Transport Protocol to UDP-Lite in the Configuration Status Request or
   Image Data Request message if the AC advertised support for UDP-Lite,
   the message was received over IPv6, the CAPWAP Local IPv6 Address
   message element (see Section 4.6.12) and no middlebox was detected
   (see Section 11).  Upon receiving either the Configuration Status
   Request or the Image Data Request, the AC MUST observe the preference
   indicated by the WTP in the CAPWAP Transport Protocol, as long as it
   is consistent with what the AC advertised in the Join Response.

   For any other condition, the CAPWAP Transport Protocol MUST be set to
   UDP.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |   Transport   |
     +-+-+-+-+-+-+-+-+

   Type:   51 for CAPWAP Transport Protocol

   Length:   1

   Transport:   The transport to use for the CAPWAP Data channel.  The
      following enumerated values are supported:

      1 -   UDP-Lite: The UDP-Lite transport protocol is to be used for
            the CAPWAP Data channel.  Note that this option MUST NOT be
            used if the CAPWAP Control channel is being used over IPv4.

      2 -   UDP: The UDP transport protocol is to be used for the CAPWAP
            Data channel.

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4.6.15.  Data Transfer Data

   The Data Transfer Data message element is used by the WTP to provide
   information to the AC for debugging purposes.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Data Type   |   Data Mode   |         Data Length           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Data ....
     +-+-+-+-+-+-+-+-+

   Type:   13 for Data Transfer Data

   Length:   >= 5

   Data Type:   An 8-bit value representing the transfer Data Type.  The
      following enumerated values are supported:

      1 -  Transfer data is included.

      2 -  Last Transfer Data Block is included (End of File (EOF)).

      5 -  An error occurred.  Transfer is aborted.

   Data Mode:   An 8-bit value describing the type of information being
      transmitted.  The following enumerated values are supported:

      0 -  Reserved

      1 -  WTP Crash Data

      2 -  WTP Memory Dump

   Data Length:   Length of data field, with a maximum size of 65535.

   Data:   Data being transferred from the WTP to the AC, whose type is
      identified via the Data Mode field.

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4.6.16.  Data Transfer Mode

   The Data Transfer Mode message element is used by the WTP to indicate
   the type of data transfer information it is sending to the AC for
   debugging purposes.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |   Data Mode   |
     +-+-+-+-+-+-+-+-+

   Type:   14 for Data Transfer Mode

   Length:   1

   Data Mode:   An 8-bit value describing the type of information being
      requested.  The following enumerated values are supported:

      0 -  Reserved

      1 -  WTP Crash Data

      2 -  WTP Memory Dump

4.6.17.  Decryption Error Report

   The Decryption Error Report message element value is used by the WTP
   to inform the AC of decryption errors that have occurred since the
   last report.  Note that this error reporting mechanism is not used if
   encryption and decryption services are provided in the AC.

      0                   1                   2
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |Num Of Entries |     Length    | MAC Address...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   15 for Decryption Error Report

   Length:   >= 9

   Radio ID:   The Radio Identifier refers to an interface index on the
      WTP, whose value is between one (1) and 31.

   Num of Entries:   The number of instances of the Length/MAC Address
      fields in the array.  This field MUST NOT exceed the value of 255.

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   Length:  The length of the MAC Address field.  The formats and
      lengths specified in [EUI-48] and [EUI-64] are supported.

   MAC Address:   MAC address of the station that has caused decryption
      errors.

4.6.18.  Decryption Error Report Period

   The Decryption Error Report Period message element value is used by
   the AC to inform the WTP how frequently it should send decryption
   error report messages.  Note that this error reporting mechanism is
   not used if encryption and decryption services are provided in the
   AC.

      0                   1                   2
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |        Report Interval        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   16 for Decryption Error Report Period

   Length:   3

   Radio ID:   The Radio Identifier refers to an interface index on the
      WTP, whose value is between one (1) and 31.

   Report Interval:   A 16-bit unsigned integer indicating the time, in
      seconds.  The default value for this message element can be found
      in Section 4.7.11.

4.6.19.  Delete MAC ACL Entry

   The Delete MAC ACL Entry message element is used by an AC to delete a
   MAC ACL entry on a WTP, ensuring that the WTP provides service to the
   MAC addresses provided in the message.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Num of Entries|     Length    |          MAC Address ...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   17 for Delete MAC ACL Entry

   Length:   >= 8

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   Num of Entries:   The number of instances of the Length/MAC Address
      fields in the array.  This field MUST NOT exceed the value of 255.

   Length:  The length of the MAC Address field.  The formats and
      lengths specified in [EUI-48] and [EUI-64] are supported.

   MAC Address:   An array of MAC addresses to delete from the ACL.

4.6.20.  Delete Station

   The Delete Station message element is used by the AC to inform a WTP
   that it should no longer provide service to a particular station.
   The WTP MUST terminate service to the station immediately upon
   receiving this message element.

   The transmission of a Delete Station message element could occur for
   various reasons, including for administrative reasons, or if the
   station has roamed to another WTP.

   The Delete Station message element MAY be sent by the WTP, in the WTP
   Event Request message, to inform the AC that a particular station is
   no longer being provided service.  This could occur as a result of an
   Idle Timeout (see section 4.4.43), due to internal resource shortages
   or for some other reason.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Radio ID   |     Length    |        MAC Address...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   18 for Delete Station

   Length:   >= 8

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   Length:  The length of the MAC Address field.  The formats and
      lengths specified in [EUI-48] and [EUI-64] are supported.

   MAC Address:   The station's MAC address.

4.6.21.  Discovery Type

   The Discovery Type message element is used by the WTP to indicate how
   it has come to know about the existence of the AC to which it is
   sending the Discovery Request message.

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      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     | Discovery Type|
     +-+-+-+-+-+-+-+-+

   Type:   20 for Discovery Type

   Length:   1

   Discovery Type:   An 8-bit value indicating how the WTP discovered
      the AC.  The following enumerated values are supported:

      0 -   Unknown

      1 -   Static Configuration

      2 -   DHCP

      3 -   DNS

      4 -   AC Referral (used when the AC was configured either through
            the AC IPv4 List or AC IPv6 List message element)

4.6.22.  Duplicate IPv4 Address

   The Duplicate IPv4 Address message element is used by a WTP to inform
   an AC that it has detected another IP device using the same IP
   address that the WTP is currently using.

   The WTP MUST transmit this message element with the status set to 1
   after it has detected a duplicate IP address.  When the WTP detects
   that the duplicate IP address has been cleared, it MUST send this
   message element with the status set to 0.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          IP Address                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Status    |     Length    |          MAC Address ...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   21 for Duplicate IPv4 Address

   Length:   >= 12

   IP Address:   The IP address currently used by the WTP.

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   Status:   The status of the duplicate IP address.  The value MUST be
      set to 1 when a duplicate address is detected, and 0 when the
      duplicate address has been cleared.

   Length:  The length of the MAC Address field.  The formats and
      lengths specified in [EUI-48] and [EUI-64] are supported.

   MAC Address:   The MAC address of the offending device.

4.6.23.  Duplicate IPv6 Address

   The Duplicate IPv6 Address message element is used by a WTP to inform
   an AC that it has detected another host using the same IP address
   that the WTP is currently using.

   The WTP MUST transmit this message element with the status set to 1
   after it has detected a duplicate IP address.  When the WTP detects
   that the duplicate IP address has been cleared, it MUST send this
   message element with the status set to 0.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          IP Address                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          IP Address                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          IP Address                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          IP Address                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Status    |     Length    |         MAC Address ...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   22 for Duplicate IPv6 Address

   Length:   >= 24

   IP Address:   The IP address currently used by the WTP.

   Status:   The status of the duplicate IP address.  The value MUST be
      set to 1 when a duplicate address is detected, and 0 when the
      duplicate address has been cleared.

   Length:  The length of the MAC Address field.  The formats and
      lengths specified in [EUI-48] and [EUI-64] are supported.

   MAC Address:   The MAC address of the offending device.

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4.6.24.  Idle Timeout

   The Idle Timeout message element is sent by the AC to the WTP to
   provide the Idle Timeout value that the WTP SHOULD enforce for its
   active stations.  The value applies to all radios on the WTP.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                            Timeout                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   23 for Idle Timeout

   Length:   4

   Timeout:   The current Idle Timeout, in seconds, to be enforced by
      the WTP.  The default value for this message element is specified
      in Section 4.7.8.

4.6.25.  ECN Support

   The ECN Support message element is sent by both the WTP and the AC to
   indicate their support for the Explicit Congestion Notification (ECN)
   bits, as defined in [RFC3168].

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |  ECN Support  |
     +-+-+-+-+-+-+-+-+

   Type:   53 for ECN Support

   Length:   1

   ECN Support:   An 8-bit value representing the sender's support for
      ECN, as defined in [RFC3168].  All CAPWAP Implementations MUST
      support the Limited ECN Support mode.  Full ECN Support is used if
      both the WTP and AC advertise the capability for "Full and Limited
      ECN" Support; otherwise, Limited ECN Support is used.

      0 -  Limited ECN Support

      1 -  Full and Limited ECN Support

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4.6.26.  Image Data

   The Image Data message element is present in the Image Data Request
   message sent by the AC and contains the following fields.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Data Type   |                    Data ....
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   24 for Image Data

   Length:   >= 1

   Data Type:   An 8-bit value representing the image Data Type.  The
      following enumerated values are supported:

      1 -  Image data is included.

      2 -  Last Image Data Block is included (EOF).

      5 -  An error occurred.  Transfer is aborted.

   Data:   The Image Data field contains up to 1024 characters, and its
      length is inferred from this message element's length field.  If
      the block being sent is the last one, the Data Type field is set
      to 2.  The AC MAY opt to abort the data transfer by setting the
      Data Type field to 5.  When the Data Type field is 5, the Value
      field has a zero length.

4.6.27.  Image Identifier

   The Image Identifier message element is sent by the AC to the WTP to
   indicate the expected active software version that is to be run on
   the WTP.  The WTP sends the Image Identifier message element in order
   to request a specific software version from the AC.  The actual
   download process is defined in Section 9.1.  The value is a variable-
   length UTF-8 encoded string [RFC3629], which is NOT zero terminated.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                       Vendor Identifier                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Data...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

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   Type:   25 for Image Identifier

   Length:   >= 5

   Vendor Identifier:   A 32-bit value containing the IANA-assigned "SMI
      Network Management Private Enterprise Codes".

   Data:   A variable-length UTF-8 encoded string [RFC3629] containing
      the firmware identifier to be run on the WTP, whose length MUST
      NOT exceed 1024 octets.  The length of this field is inferred from
      this message element's length field.

4.6.28.  Image Information

   The Image Information message element is present in the Image Data
   Response message sent by the AC to the WTP and contains the following
   fields.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           File Size                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              Hash                             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              Hash                             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              Hash                             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              Hash                             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   26 for Image Information

   Length:   20

   File Size:   A 32-bit value containing the size of the file, in
      bytes, that will be transferred by the AC to the WTP.

   Hash:   A 16-octet MD5 hash of the image using the procedures defined
      in [RFC1321].

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4.6.29.  Initiate Download

   The Initiate Download message element is used by the WTP to inform
   the AC that the AC SHOULD initiate a firmware upgrade.  The AC
   subsequently transmits an Image Data Request message, which includes
   the Image Data message element.  This message element does not
   contain any data.

   Type:   27 for Initiate Download

   Length:   0

4.6.30.  Location Data

   The Location Data message element is a variable-length byte UTF-8
   encoded string [RFC3629] containing user-defined location information
   (e.g., "Next to Fridge").  This information is configurable by the
   network administrator, and allows the WTP location to be determined.
   The string is not zero terminated.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+-
     | Location ...
     +-+-+-+-+-+-+-+-+-

   Type:   28 for Location Data

   Length:   >= 1

   Location:   A non-zero-terminated UTF-8 encoded string [RFC3629]
      containing the WTP location, whose maximum size MUST NOT exceed
      1024.

4.6.31.  Maximum Message Length

   The Maximum Message Length message element is included in the Join
   Request message by the WTP to indicate the maximum CAPWAP message
   length that it supports to the AC.  The Maximum Message Length
   message element is optionally included in Join Response message by
   the AC to indicate the maximum CAPWAP message length that it supports
   to the WTP.

         0              1
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |    Maximum Message Length     |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

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   Type:   29 for Maximum Message Length

   Length:   2

   Maximum Message Length  A 16-bit unsigned integer indicating the
      maximum message length.

4.6.32.  MTU Discovery Padding

   The MTU Discovery Padding message element is used as padding to
   perform MTU discovery, and MUST contain octets of value 0xFF, of any
   length.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |  Padding...
     +-+-+-+-+-+-+-+-


   Type:   52 for MTU Discovery Padding

   Length:   Variable

   Pad:   A variable-length pad, filled with the value 0xFF.

4.6.33.  Radio Administrative State

   The Radio Administrative State message element is used to communicate
   the state of a particular radio.  The Radio Administrative State
   message element is sent by the AC to change the state of the WTP.
   The WTP saves the value, to ensure that it remains across WTP resets.
   The WTP communicates this message element during the configuration
   phase, in the Configuration Status Request message, to ensure that
   the AC has the WTP radio current administrative state settings.  The
   message element contains the following fields:

         0                   1
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |  Admin State  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   31 for Radio Administrative State

   Length:   2

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   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.  The Radio ID field MAY also
      include the value of 0xff, which is used to identify the WTP.  If
      an AC wishes to change the administrative state of a WTP, it
      includes 0xff in the Radio ID field.

   Admin State:   An 8-bit value representing the administrative state
      of the radio.  The default value for the Admin State field is
      listed in Section 4.8.1.  The following enumerated values are
      supported:

      0 -  Reserved

      1 -  Enabled

      2 -  Disabled

4.6.34.  Radio Operational State

   The Radio Operational State message element is sent by the WTP to the
   AC to communicate a radio's operational state.  This message element
   is included in the Configuration Update Response message by the WTP
   if it was requested to change the state of its radio, via the Radio
   Administrative State message element, but was unable to comply to the
   request.  This message element is included in the Change State Event
   message when a WTP radio state was changed unexpectedly.  This could
   occur due to a hardware failure.  Note that the operational state
   setting is not saved on the WTP, and therefore does not remain across
   WTP resets.  The value contains three fields, as shown below.

      0                   1                   2
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |     State     |     Cause     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   32 for Radio Operational State

   Length:   3

   Radio ID:   The Radio Identifier refers to an interface index on the
      WTP, whose value is between one (1) and 31.  A value of 0xFF is
      invalid, as it is not possible to change the WTP's operational
      state.

   State:   An 8-bit Boolean value representing the state of the radio.
      The following enumerated values are supported:

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      0 -  Reserved

      1 -  Enabled

      2 -  Disabled

   Cause:   When a radio is inoperable, the cause field contains the
      reason the radio is out of service.  The following enumerated
      values are supported:

      0 -  Normal

      1 -  Radio Failure

      2 -  Software Failure

      3 -  Administratively Set

4.6.35.  Result Code

   The Result Code message element value is a 32-bit integer value,
   indicating the result of the Request message corresponding to the
   sequence number included in the Response message.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         Result Code                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   33 for Result Code

   Length:   4

   Result Code:   The following enumerated values are defined:

      0  Success

      1  Failure (AC List Message Element MUST Be Present)

      2  Success (NAT Detected)

      3  Join Failure (Unspecified)

      4  Join Failure (Resource Depletion)

      5  Join Failure (Unknown Source)

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      6  Join Failure (Incorrect Data)

      7  Join Failure (Session ID Already in Use)

      8  Join Failure (WTP Hardware Not Supported)

      9  Join Failure (Binding Not Supported)

      10 Reset Failure (Unable to Reset)

      11 Reset Failure (Firmware Write Error)

      12 Configuration Failure (Unable to Apply Requested Configuration
         - Service Provided Anyhow)

      13 Configuration Failure (Unable to Apply Requested Configuration
         - Service Not Provided)

      14 Image Data Error (Invalid Checksum)

      15 Image Data Error (Invalid Data Length)

      16 Image Data Error (Other Error)

      17 Image Data Error (Image Already Present)

      18 Message Unexpected (Invalid in Current State)

      19 Message Unexpected (Unrecognized Request)

      20 Failure - Missing Mandatory Message Element

      21 Failure - Unrecognized Message Element

      22 Data Transfer Error (No Information to Transfer)

4.6.36.  Returned Message Element

   The Returned Message Element is sent by the WTP in the Change State
   Event Request message to communicate to the AC which message elements
   in the Configuration Status Response it was unable to apply locally.
   The Returned Message Element message element contains a result code
   indicating the reason that the configuration could not be applied,
   and encapsulates the failed message element.

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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Reason     |    Length     |       Message Element...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   34 for Returned Message Element

   Length:   >= 6

   Reason:   The reason the configuration in the offending message
      element could not be applied by the WTP.  The following enumerated
      values are supported:

      0 -  Reserved

      1 -  Unknown Message Element

      2 -  Unsupported Message Element

      3 -  Unknown Message Element Value

      4 -  Unsupported Message Element Value

   Length:   The length of the Message Element field, which MUST NOT
      exceed 255 octets.

   Message Element:   The Message Element field encapsulates the message
      element sent by the AC in the Configuration Status Response
      message that caused the error.

4.6.37.  Session ID

   The Session ID message element value contains a randomly generated
   unsigned 128-bit integer.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Session ID                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Session ID                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Session ID                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Session ID                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

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   Type:   35 for Session ID

   Length:   16

   Session ID:   A 128-bit unsigned integer used as a random session
      identifier

4.6.38.  Statistics Timer

   The Statistics Timer message element value is used by the AC to
   inform the WTP of the frequency with which it expects to receive
   updated statistics.

      0                   1
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |        Statistics Timer       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   36 for Statistics Timer

   Length:   2

   Statistics Timer:   A 16-bit unsigned integer indicating the time, in
      seconds.  The default value for this timer is specified in
      Section 4.7.14.

4.6.39.  Vendor Specific Payload

   The Vendor Specific Payload message element is used to communicate
   vendor-specific information between the WTP and the AC.  The Vendor
   Specific Payload message element MAY be present in any CAPWAP
   message.  The exchange of vendor-specific data between the MUST NOT
   modify the behavior of the base CAPWAP protocol and state machine.
   The message element uses the following format:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                       Vendor Identifier                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |          Element ID           |    Data...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   37 for Vendor Specific Payload

   Length:   >= 7

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   Vendor Identifier:   A 32-bit value containing the IANA-assigned "SMI
      Network Management Private Enterprise Codes" [RFC3232].

   Element ID:   A 16-bit Element Identifier that is managed by the
      vendor.

   Data:   Variable-length vendor-specific information, whose contents
      and format are proprietary and understood based on the Element ID
      field.  This field MUST NOT exceed 2048 octets.

4.6.40.  WTP Board Data

   The WTP Board Data message element is sent by the WTP to the AC and
   contains information about the hardware present.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                       Vendor Identifier                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                   Board Data Sub-Element...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   38 for WTP Board Data

   Length:   >=14

   Vendor Identifier:   A 32-bit value containing the IANA-assigned "SMI
      Network Management Private Enterprise Codes", identifying the WTP
      hardware manufacturer.  The Vendor Identifier field MUST NOT be
      set to zero.

   Board Data Sub-Element:   The WTP Board Data message element contains
      multiple Board Data sub-elements, some of which are mandatory and
      some are optional, as described below.  The Board Data Type values
      are not extensible by vendors, and are therefore not coupled along
      with the Vendor Identifier field.  The Board Data sub-element has
      the following format:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |        Board Data Type        |       Board Data Length       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                      Board Data Value...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

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      Board Data Type:   The Board Data Type field identifies the data
         being encoded.  The CAPWAP protocol defines the following
         values, and each of these types identify whether their presence
         is mandatory or optional:

      0 -   WTP Model Number: The WTP Model Number MUST be included in
            the WTP Board Data message element.

      1 -   WTP Serial Number: The WTP Serial Number MUST be included in
            the WTP Board Data message element.

      2 -   Board ID: A hardware identifier, which MAY be included in
            the WTP Board Data message element.

      3 -   Board Revision: A revision number of the board, which MAY be
            included in the WTP Board Data message element.

      4 -   Base MAC Address: The WTP's Base MAC address, which MAY be
            assigned to the primary Ethernet interface.

   Board Data Length:   The length of the data in the Board Data Value
      field, whose length MUST NOT exceed 1024 octets.

   Board Data Value:   The data associated with the Board Data Type
      field for this Board Data sub-element.

4.6.41.  WTP Descriptor

   The WTP Descriptor message element is used by a WTP to communicate
   its current hardware and software (firmware) configuration.  The
   value contains the following fields:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Max Radios  | Radios in use |  Num Encrypt  |Encryp Sub-Elmt|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Encryption Sub-Element    |    Descriptor Sub-Element...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   39 for WTP Descriptor

   Length:   >= 33

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   Max Radios:   An 8-bit value representing the number of radios (where
      each radio is identified via the Radio ID field) supported by the
      WTP.

   Radios in use:   An 8-bit value representing the number of radios in
      use in the WTP.

   Num Encrypt:   The number of 3-byte Encryption sub-elements that
      follow this field.  The value of the Num Encrypt field MUST be
      between one (1) and 255.

   Encryption Sub-Element:   The WTP Descriptor message element MUST
      contain at least one Encryption sub-element.  One sub-element is
      present for each binding supported by the WTP.  The Encryption
      sub-element has the following format:

      0                   1                   2
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Resvd|  WBID   |  Encryption Capabilities      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Resvd:  The 3-bit field is reserved for future use.  All
         implementations complying with this protocol MUST set to zero
         any bits that are reserved in the version of the protocol
         supported by that implementation.  Receivers MUST ignore all
         bits not defined for the version of the protocol they support.

      WBID:   A 5-bit field that is the wireless binding identifier.
         The identifier will indicate the type of wireless packet
         associated with the radio.  The WBIDs defined in this
         specification can be found in Section 4.3.

      Encryption Capabilities:   This 16-bit field is used by the WTP to
         communicate its capabilities to the AC.  A WTP that does not
         have any encryption capabilities sets this field to zero (0).
         Refer to the specific wireless binding for further
         specification of the Encryption Capabilities field.

   Descriptor Sub-Element:   The WTP Descriptor message element contains
      multiple Descriptor sub-elements, some of which are mandatory and
      some are optional, as described below.  The Descriptor sub-element
      has the following format:

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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                  Descriptor Vendor Identifier                 |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |        Descriptor Type        |       Descriptor Length       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                       Descriptor Data...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Descriptor Vendor Identifier:   A 32-bit value containing the
         IANA-assigned "SMI Network Management Private Enterprise
         Codes".

      Descriptor Type:   The Descriptor Type field identifies the data
         being encoded.  The format of the data is vendor-specific
         encoded in the UTF-8 format [RFC3629].  The CAPWAP protocol
         defines the following values, and each of these types identify
         whether their presence is mandatory or optional.  The values
         listed below are used in conjunction with the Descriptor Vendor
         Identifier field, whose value MUST be set to zero (0).  This
         field, combined with the Descriptor Vendor Identifier set to a
         non-zero (0) value, allows vendors to use a private namespace.

         0 -   Hardware Version: The WTP hardware version number MUST be
               present.

         1 -   Active Software Version: The WTP running software version
               number MUST be present.

         2 -   Boot Version: The WTP boot loader version number MUST be
               present.

         3 -   Other Software Version: The WTP non-running software
               (firmware) version number MAY be present.  This type is
               used to communicate alternate software versions that are
               available on the WTP's non-volatile storage.

      Descriptor Length:   Length of the vendor-specific encoding of the
         Descriptor Data field, whose length MUST NOT exceed 1024
         octets.

      Descriptor Data:   Vendor-specific data of WTP information encoded
         in the UTF-8 format [RFC3629].

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4.6.42.  WTP Fallback

   The WTP Fallback message element is sent by the AC to the WTP to
   enable or disable automatic CAPWAP fallback in the event that a WTP
   detects its preferred AC to which it is not currently connected.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |     Mode      |
     +-+-+-+-+-+-+-+-+

   Type:   40 for WTP Fallback

   Length:   1

   Mode:   The 8-bit value indicates the status of automatic CAPWAP
      fallback on the WTP.  When enabled, if the WTP detects that its
      primary AC is available, and that the WTP is not connected to the
      primary AC, the WTP SHOULD automatically disconnect from its
      current AC and reconnect to its primary AC.  If disabled, the WTP
      will only reconnect to its primary AC through manual intervention
      (e.g., through the Reset Request message).  The default value for
      this field is specified in Section 4.8.9.  The following
      enumerated values are supported:

      0 -  Reserved

      1 -  Enabled

      2 -  Disabled

4.6.43.  WTP Frame Tunnel Mode

   The WTP Frame Tunnel Mode message element allows the WTP to
   communicate the tunneling modes of operation that it supports to the
   AC.  A WTP that advertises support for all types allows the AC to
   select which type will be used, based on its local policy.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |Reservd|N|E|L|U|
     +-+-+-+-+-+-+-+-+

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   Type:   41 for WTP Frame Tunnel Mode

   Length:   1

   Reservd:   A set of reserved bits for future use.  All
      implementations complying with this protocol MUST set to zero any
      bits that are reserved in the version of the protocol supported by
      that implementation.  Receivers MUST ignore all bits not defined
      for the version of the protocol they support.

   N:    Native Frame Tunnel mode requires the WTP and AC to encapsulate
         all user payloads as native wireless frames, as defined by the
         wireless binding (see for example Section 4.4)

   E:    The 802.3 Frame Tunnel Mode requires the WTP and AC to
         encapsulate all user payload as native IEEE 802.3 frames (see
         Section 4.4).  All user traffic is tunneled to the AC.  This
         value MUST NOT be used when the WTP MAC Type is set to Split
         MAC.

   L:    When Local Bridging is used, the WTP does not tunnel user
         traffic to the AC; all user traffic is locally bridged.  This
         value MUST NOT be used when the WTP MAC Type is set to Split
         MAC.

   R:    A reserved bit for future use.  All implementations complying
         with this protocol MUST set to zero any bits that are reserved
         in the version of the protocol supported by that
         implementation.  Receivers MUST ignore all bits not defined for
         the version of the protocol they support.

4.6.44.  WTP MAC Type

   The WTP MAC-Type message element allows the WTP to communicate its
   mode of operation to the AC.  A WTP that advertises support for both
   modes allows the AC to select the mode to use, based on local policy.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |   MAC Type    |
     +-+-+-+-+-+-+-+-+

   Type:   44 for WTP MAC Type

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   Length:   1

   MAC Type:   The MAC mode of operation supported by the WTP.  The
      following enumerated values are supported:

      0 -   Local MAC: Local MAC is the default mode that MUST be
            supported by all WTPs.  When tunneling is enabled (see
            Section 4.6.43), the encapsulated frames MUST be in the
            802.3 format (see Section 4.4.2), unless a wireless
            management or control frame which MAY be in its native
            format.  Any CAPWAP binding needs to specify the format of
            management and control wireless frames.

      1 -   Split MAC: Split MAC support is optional, and allows the AC
            to receive and process native wireless frames.

      2 -   Both: WTP is capable of supporting both Local MAC and Split
            MAC.

4.6.45.  WTP Name

   The WTP Name message element is a variable-length byte UTF-8 encoded
   string [RFC3629].  The string is not zero terminated.

      0
      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+-
     |  WTP Name ...
     +-+-+-+-+-+-+-+-+-

   Type:   45 for WTP Name

   Length:   >= 1

   WTP Name:   A non-zero-terminated UTF-8 encoded string [RFC3629]
      containing the WTP name, whose maximum size MUST NOT exceed 512
      bytes.

4.6.46.  WTP Radio Statistics

   The WTP Radio Statistics message element is sent by the WTP to the AC
   to communicate statistics on radio behavior and reasons why the WTP
   radio has been reset.  These counters are never reset on the WTP, and
   will therefore roll over to zero when the maximum size has been
   reached.

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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    | Last Fail Type|          Reset Count          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       SW Failure Count        |        HW Failure Count       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Other  Failure Count      |     Unknown Failure Count     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      Config Update Count      |     Channel Change Count      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       Band Change Count       |      Current Noise Floor      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   47 for WTP Radio Statistics

   Length:   20

   Radio ID:   The radio ID of the radio to which the statistics apply,
      whose value is between one (1) and 31.

   Last Failure Type:   The last WTP failure.  The following enumerated
      values are supported:

      0 -  Statistic Not Supported

      1 -  Software Failure

      2 -  Hardware Failure

      3 -  Other Failure

      255 -  Unknown (e.g., WTP doesn't keep track of info)

   Reset Count:   The number of times that the radio has been reset.

   SW Failure Count:   The number of times that the radio has failed due
      to software-related reasons.

   HW Failure Count:   The number of times that the radio has failed due
      to hardware-related reasons.

   Other Failure Count:   The number of times that the radio has failed
      due to known reasons, other than software or hardware failure.

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   Unknown Failure Count:   The number of times that the radio has
      failed for unknown reasons.

   Config Update Count:   The number of times that the radio
      configuration has been updated.

   Channel Change Count:   The number of times that the radio channel
      has been changed.

   Band Change Count:   The number of times that the radio has changed
      frequency bands.

   Current Noise Floor:   A signed integer that indicates the noise
      floor of the radio receiver in units of dBm.

4.6.47.  WTP Reboot Statistics

   The WTP Reboot Statistics message element is sent by the WTP to the
   AC to communicate reasons why WTP reboots have occurred.  These
   counters are never reset on the WTP, and will therefore roll over to
   zero when the maximum size has been reached.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Reboot Count          |      AC Initiated Count       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      Link Failure Count       |       SW Failure Count        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       HW Failure Count        |      Other Failure Count      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Unknown Failure Count     |Last Failure Type|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   48 for WTP Reboot Statistics

   Length:   15

   Reboot Count:   The number of reboots that have occurred due to a WTP
      crash.  A value of 65535 implies that this information is not
      available on the WTP.

   AC Initiated Count:   The number of reboots that have occurred at the
      request of a CAPWAP protocol message, such as a change in
      configuration that required a reboot or an explicit CAPWAP
      protocol reset request.  A value of 65535 implies that this
      information is not available on the WTP.

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   Link Failure Count:   The number of times that a CAPWAP protocol
      connection with an AC has failed due to link failure.

   SW Failure Count:   The number of times that a CAPWAP protocol
      connection with an AC has failed due to software-related reasons.

   HW Failure Count:   The number of times that a CAPWAP protocol
      connection with an AC has failed due to hardware-related reasons.

   Other Failure Count:   The number of times that a CAPWAP protocol
      connection with an AC has failed due to known reasons, other than
      AC initiated, link, SW or HW failure.

   Unknown Failure Count:   The number of times that a CAPWAP protocol
      connection with an AC has failed for unknown reasons.

   Last Failure Type:   The failure type of the most recent WTP failure.
      The following enumerated values are supported:

      0 -  Not Supported

      1 -  AC Initiated (see Section 9.2)

      2 -  Link Failure

      3 -  Software Failure

      4 -  Hardware Failure

      5 -  Other Failure

      255 -  Unknown (e.g., WTP doesn't keep track of info)

4.6.48.  WTP Static IP Address Information

   The WTP Static IP Address Information message element is used by an
   AC to configure or clear a previously configured static IP address on
   a WTP.  IPv6 WTPs are expected to use dynamic addresses.

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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          IP Address                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                            Netmask                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                            Gateway                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Static     |
     +-+-+-+-+-+-+-+-+

   Type:   49 for WTP Static IP Address Information

   Length:   13

   IP Address:   The IP address to assign to the WTP.  This field is
      only valid if the static field is set to one.

   Netmask:   The IP Netmask.  This field is only valid if the static
      field is set to one.

   Gateway:   The IP address of the gateway.  This field is only valid
      if the static field is set to one.

   Static:   An 8-bit Boolean stating whether or not the WTP should use
      a static IP address.  A value of zero disables the static IP
      address, while a value of one enables it.

4.7.  CAPWAP Protocol Timers

   This section contains the definition of the CAPWAP timers.

4.7.1.  ChangeStatePendingTimer

   The maximum time, in seconds, the AC will wait for the Change State
   Event Request from the WTP after having transmitted a successful
   Configuration Status Response message.

   Default: 25 seconds

4.7.2.  DataChannelKeepAlive

   The DataChannelKeepAlive timer is used by the WTP to determine the
   next opportunity when it must transmit the Data Channel Keep-Alive,
   in seconds.

   Default: 30 seconds

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4.7.3.  DataChannelDeadInterval

   The minimum time, in seconds, a WTP MUST wait without having received
   a Data Channel Keep-Alive packet before the destination for the Data
   Channel Keep-Alive packets may be considered dead.  The value of this
   timer MUST be no less than 2*DataChannelKeepAlive seconds and no
   greater that 240 seconds.

   Default: 60

4.7.4.  DataCheckTimer

   The number of seconds the AC will wait for the Data Channel Keep
   Alive, which is required by the CAPWAP state machine's Data Check
   state.  The AC resets the state machine if this timer expires prior
   to transitioning to the next state.

   Default: 30

4.7.5.  DiscoveryInterval

   The minimum time, in seconds, that a WTP MUST wait after receiving a
   Discovery Response message, before initiating a DTLS handshake.

   Default: 5

4.7.6.  DTLSSessionDelete

   The minimum time, in seconds, a WTP MUST wait for DTLS session
   deletion.

   Default: 5

4.7.7.  EchoInterval

   The minimum time, in seconds, between sending Echo Request messages
   to the AC with which the WTP has joined.

   Default: 30

4.7.8.  IdleTimeout

   The default Idle Timeout is 300 seconds.

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4.7.9.  ImageDataStartTimer

   The number of seconds the WTP will wait for its peer to transmit the
   Image Data Request.

   Default: 30

4.7.10.  MaxDiscoveryInterval

   The maximum time allowed between sending Discovery Request messages,
   in seconds.  This value MUST be no less than 2 seconds and no greater
   than 180 seconds.

   Default: 20 seconds.

4.7.11.  ReportInterval

   The ReportInterval is used by the WTP to determine the interval the
   WTP uses between sending the Decryption Error message elements to
   inform the AC of decryption errors, in seconds.

   The default Report Interval is 120 seconds.

4.7.12.  RetransmitInterval

   The minimum time, in seconds, in which a non-acknowledged CAPWAP
   packet will be retransmitted.

   Default: 3

4.7.13.  SilentInterval

   For a WTP, this is the minimum time, in seconds, a WTP MUST wait
   before it MAY again send Discovery Request messages or attempt to
   establish a DTLS session.  For an AC, this is the minimum time, in
   seconds, during which the AC SHOULD ignore all CAPWAP and DTLS
   packets received from the WTP that is in the Sulking state.

   Default: 30 seconds

4.7.14.  StatisticsTimer

   The StatisticsTimer is used by the WTP to determine the interval the
   WTP uses between the WTP Events Requests it transmits to the AC to
   communicate its statistics, in seconds.

   Default: 120 seconds

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4.7.15.  WaitDTLS

   The maximum time, in seconds, a WTP MUST wait without having received
   a DTLS Handshake message from an AC.  This timer MUST be greater than
   30 seconds.

   Default: 60

4.7.16.  WaitJoin

   The maximum time, in seconds, an AC will wait after the DTLS session
   has been established until it receives the Join Request from the WTP.
   This timer MUST be greater than 20 seconds.

   Default: 60

4.8.  CAPWAP Protocol Variables

   This section defines the CAPWAP protocol variables, which are used
   for various protocol functions.  Some of these variables are
   configurable, while others are counters or have a fixed value.  For
   non-counter-related variables, default values are specified.
   However, when a WTP's variable configuration is explicitly overridden
   by an AC, the WTP MUST save the new value.

4.8.1.  AdminState

   The default Administrative State value is enabled (1).

4.8.2.  DiscoveryCount

   The number of Discovery Request messages transmitted by a WTP to a
   single AC.  This is a monotonically increasing counter.

4.8.3.  FailedDTLSAuthFailCount

   The number of failed DTLS session establishment attempts due to
   authentication failures.

4.8.4.  FailedDTLSSessionCount

   The number of failed DTLS session establishment attempts.

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4.8.5.  MaxDiscoveries

   The maximum number of Discovery Request messages that will be sent
   after a WTP boots.

   Default: 10

4.8.6.  MaxFailedDTLSSessionRetry

   The maximum number of failed DTLS session establishment attempts
   before the CAPWAP device enters a silent period.

   Default: 3

4.8.7.  MaxRetransmit

   The maximum number of retransmissions for a given CAPWAP packet
   before the link layer considers the peer dead.

   Default: 5

4.8.8.  RetransmitCount

   The number of retransmissions for a given CAPWAP packet.  This is a
   monotonically increasing counter.

4.8.9.  WTPFallBack

   The default WTP Fallback value is enabled (1).

4.9.  WTP Saved Variables

   In addition to the values defined in Section 4.8, the following
   values SHOULD be saved on the WTP in non-volatile memory.  CAPWAP
   wireless bindings MAY define additional values that SHOULD be stored
   on the WTP.

4.9.1.  AdminRebootCount

   The number of times the WTP has rebooted administratively, defined in
   Section 4.6.47.

4.9.2.  FrameEncapType

   For WTPs that support multiple Frame Encapsulation Types, it is
   useful to save the value configured by the AC.  The Frame
   Encapsulation Type is defined in Section 4.6.43.

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4.9.3.  LastRebootReason

   The reason why the WTP last rebooted, defined in Section 4.6.47.

4.9.4.  MacType

   For WTPs that support multiple MAC-Types, it is useful to save the
   value configured by the AC.  The MAC-Type is defined in
   Section 4.6.44.

4.9.5.  PreferredACs

   The preferred ACs, with the index, defined in Section 4.6.5.

4.9.6.  RebootCount

   The number of times the WTP has rebooted, defined in Section 4.6.47.

4.9.7.  Static IP Address

   The static IP address assigned to the WTP, as configured by the WTP
   Static IP address Information message element (see Section 4.6.48).

4.9.8.  WTPLinkFailureCount

   The number of times the link to the AC has failed, see
   Section 4.6.47.

4.9.9.  WTPLocation

   The WTP Location, defined in Section 4.6.30.

4.9.10.  WTPName

   The WTP Name, defined in Section 4.6.45.



(page 103 continued on part 5)

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