Subject: [Capwap] Proposed Text for Issue 18: use MIB variable names instead

From: "Pat Calhoun (pacalhou)" <[email-masked]>
Date: Mon, 22 May 2006 12:15:01 -0700

All,
 
This issue has been opened for quite some time, and I finally got around
to handling it. Note that when this issue was first raised, I stated
that we should not adopt the names to the MIB elements, but did agree
that references would be useful. In doing this, I used the soon to be
802.11-2006 specification, and found a few issues that I have fixed.
 
Please note that given the breath of the changes here, I am only
including context and the proposed changes. Unfortunately, this change
touches many parts of the text, so this e-mail will be quite lengthy.

Other than references to MIB values, the following have changed
significantly:
- 11.10.9. It was used by the WTP to report MIC failures, but the
802.11i specification actually includes many other failures that need to
be reported.
- 11.10.14. This section was missing some statistics that were added as
part of the 802.11e specification.

As usual, comments are welcomed.
 
[...]
11.10.2.  IEEE 802.11 Antenna
[...]
   Diversity:  An 8-bit value specifying whether the antenna is to
      provide receive diversity.  The value of this field is the same as
      the IEEE 802.11 dot11DiversitySelectionRx MIB element (see [6]).
      The following values are supported:
[...]
   Antenna Count:  An 8-bit value specifying the number of Antenna
      Selection fields.  This value should be the same as the one found
      in the IEEE 802.11 dot11CurrentTxAntenna MIB element (see [6]).

[...]
11.10.5.  IEEE 802.11 Direct Sequence Control
[...]
   Current Channel:  This attribute contains the current operating
      frequency channel of the DSSS PHY.  This value comes from the IEEE
      802.11 dot11CurrentChannel MIB element (see [6]).

   Current CCA:  The current CCA method in operation, whose value can be
      found in the IEEE 802.11 dot11CCAModeSupported MIB element (see
      [6]).  Valid values are:
[...]
   Energy Detect Threshold:  The current Energy Detect Threshold being
      used by the DSSS PHY.  The value can be found in the IEEE 802.11
      dot11EDThreshold MIB element (see [6]).

[...]
11.10.7.  IEEE 802.11 MAC Operation
[...]
   RTS Threshold:  This attribute indicates the number of octets in an
      MPDU, below which an RTS/CTS handshake MUST NOT be performed.  An
      RTS/CTS handshake MUST be performed at the beginning of any frame
      exchange sequence where the MPDU is of type Data or Management,
      the MPDU has an individual address in the Address1 field, and the
      length of the MPDU is greater than this threshold.  Setting this
      attribute to be larger than the maximum MSDU size MUST have the
      effect of turning off the RTS/CTS handshake for frames of Data or

Calhoun, Editor, et al.  Expires November 23, 2006            [Page 111]

Internet-Draft        CAPWAP Protocol Specification             May 2006

      Management type transmitted by this STA.  Setting this attribute
      to zero MUST have the effect of turning on the RTS/CTS handshake
      for all frames of Data or Management type transmitted by this STA.
      The default value of this attribute MUST be 2347.  The value of
      this field comes from the IEEE 802.11 dot11RTSThreshold MIB
      element (see [6]).

   Short Retry:  This attribute indicates the maximum number of
      transmission attempts of a frame, the length of which is less than
      or equal to RTSThreshold, that MUST be made before a failure
      condition is indicated.  The default value of this attribute MUST
      be 7.  The value of this field comes from the IEEE 802.11
      dot11ShortRetryLimit MIB element (see [6]).

   Long Retry:  This attribute indicates the maximum number of
      transmission attempts of a frame, the length of which is greater
      than dot11RTSThreshold, that MUST be made before a failure
      condition is indicated.  The default value of this attribute MUST
      be 4.  The value of this field comes from the IEEE 802.11
      dot11LongRetryLimit MIB element (see [6]).

   Fragmentation Threshold:  This attribute specifies the current
      maximum size, in octets, of the MPDU that MAY be delivered to the
      PHY.  An MSDU MUST be broken into fragments if its size exceeds
      the value of this attribute after adding MAC headers and trailers.
      An MSDU or MMPDU MUST be fragmented when the resulting frame has
      an individual address in the Address1 field, and the length of the
      frame is larger than this threshold.  The default value for this
      attribute MUST be the lesser of 2346 or the aMPDUMaxLength of the
      attached PHY and MUST never exceed the lesser of 2346 or the
      aMPDUMaxLength of the attached PHY.  The value of this attribute
      MUST never be less than 256.  The value of this field comes from
      the IEEE 802.11 dot11FragmentationThreshold MIB element (see [6]).

   Tx MSDU Lifetime:  This attribute speficies the elapsed time in TU,
      after the initial transmission of an MSDU, after which further
      attempts to transmit the MSDU MUST be terminated.  The default
      value of this attribute MUST be 512.  The value of this field
      comes from the IEEE 802.11 dot11MaxTransmitMSDULifetime MIB
      element (see [6]).

   Rx MSDU Lifetime:  This attribute specifies the elapsed time in TU,
      after the initial reception of a fragmented MMPDU or MSDU, after
      which further attempts to reassemble the MMPDU or MSDU MUST be
      terminated.  The default value MUST be 512.  The value of this
      field comes from the IEEE 802.11 dot11MaxReceiveLifetime MIB
      element (see [6]).

[...]
11.10.8.  IEEE 802.11 MIC Countermeasures

   The MIC Countermeasures message element is sent by the WTP to the AC
   to indicate the occurrence of a MIC failure.  See the IEEE 802.11
   dot11RSNATKIPCounterMeasuresInvoked MIB element (see [6]) for more
   info.

[...]
11.10.9.  IEEE 802.11 RSNA Error Report From Mobile

   The RSN Error Report From Mobile message element is sent by an AC to
   an WTP to send RSN error reports to the AC.  The WTP does not need to
   transmit any reports that do not include any failures.  The fields
   from this message element comes from the IEEE 802.11
   Dot11RSNAStatsEntry table (see [6]).

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                       Client MAC Address                      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      Client MAC Address       |             BSSID             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             BSSID                             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |    WLAN ID    |           Reserved            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        TKIP ICV Errors                        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                    TKIP Local MIC Failures                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                   TKIP Remote MIC Failures                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          CCMP Replays                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        CCMP Decrypt Errors                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          TKIP Replays                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:  1032 for IEEE 802.11 RSNA Error Report From Mobile

   Length:  14

   Client MAC Address:  The Client MAC Address of the station.

   BSSID:  The BSSID on which the failures are being reported on.

   Radio ID:  The Radio Identifier, typically refers to some interface
      index on the WTP

   WLAN ID:  The WLAN ID on which the RSNA failures are being reported.

   TKIP ICV Errors:  A 32-bit value representing the number of TKIP ICV
      errors encountered when decrypting packets from the station.  The
      value of this field comes from the IEEE 802.11
      dot11RSNAStatsTKIPICVErrors MIB element (see [6]).

   TKIP Local MIC Failures:  A 32-bit value representing the number of
      MIC failures encountered when checking the integrity of packets
      received from the station.  The value of this field comes from the
      IEEE 802.11 dot11RSNAStatsTKIPLocalMICFailures MIB element (see
      [6]).

   TKIP Remote MIC Failures:  A 32-bit value representing the number of
      MIC failures reported by the station encountered (possibly via the
      EAPOL-Key frame).  The value of this field comes from the IEEE
      802.11 dot11RSNAStatsTKIPRemoteMICFailures MIB element (see [6]).

   CCMP Replays:  A 32-bit value representing the number of CCMP MPDUs
      discarded by the replay detection mechanism.  The value of this
      field comes from the IEEE 802.11 dot11RSNACCMPReplays MIB element
      (see [6]).

   CCMP Decrypt Errors:  A 32-bit value representing the number of CCMP
      MDPUs discarded by the decryption algorithm.  The value of this
      field comes from the IEEE 802.11 dot11RSNACCMPDecryptErrors MIB
      element (see [6]).

   TKIP Replays:  A 32-bit value representing the number of TKIP Replays
      detected in frames received from the station.  The value of this
      field comes from the IEEE 802.11 dot11RSNAStatsTKIPReplays MIB
      element (see [6]).

[...]
11.10.10.  IEEE 802.11 Mobile
[...]
   Supported Rates:  The variable length field containing the supported
      rates to be used with the mobile station, as found in the IEEE
      802.11 dot11OperationalRateSet MIB element (see [6]).

[...]
11.10.12.  IEEE 802.11 Multi-domain Capability
[...]
   First Channnel #:  This attribute indicates the value of the lowest
      channel number in the subband for the associated domain country
      string.  The value of this field comes from the IEEE 802.11
      dot11FirstChannelNumber MIB element (see [6]).

   Number of Channels:  This attribute indicates the value of the total
      number of channels allowed in the subband for the associated
      domain country string.  The value of this field comes from the
      IEEE 802.11 dot11NumberofChannels MIB element (see [6]).

   Max Tx Power Level:  This attribute indicates the maximum transmit
      power, in dBm, allowed in the subband for the associated domain
      country string.  The value of this field comes from the IEEE
      802.11 dot11MaximumTransmitPowerLevel MIB element (see [6]).

[...]
11.10.13.  IEEE 802.11 OFDM Control
[...]
   Current Channel:  This attribute contains the current operating
      frequency channel of the OFDM PHY.  The value of this field comes
      from the IEEE 802.11 dot11CurrentFrequency MIB element (see [6]).

   Band Supported:  The capability of the OFDM PHY implementation to
      operate in the three U-NII bands.  The value of this field comes
      from the IEEE 802.11 dot11FrequencyBandsSupported MIB element (see
      [6]), coded as an integer value of a three bit field as follows:

         capable of operating in the lower (5.15-5.25 GHz) U-NII band

         capable of operating in the middle (5.25-5.35 GHz) U-NII band

         capable of operating in the upper (5.725-5.825 GHz) U-NII band

      For example, for an implementation capable of operating in the
      lower and mid bands this attribute would take the value

   TI Threshold:  The Threshold being used to detect a busy medium
      (frequency).  CCA MUST report a busy medium upon detecting the
      RSSI above this threshold.  The value of this field comes from the
      IEEE 802.11 dot11TIThreshold MIB element (see [6]).

[...]
11.10.14.  IEEE 802.11 Rate Set
[...]

   Rate Set:  The AC generates the Rate Set that the WTP is to include
      in it's Beacon and Probe messages.  The length of this field is
      between 2 and 8 bytes.  The value of this field comes from the
      IEEE 802.11 dot11OperationalRateSet MIB element (see [6]).

[...]
11.10.15.  IEEE 802.11 Statistics
[...]
       |                  Discarded QoS Fragment Count                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                    Associated Station Count                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                  QoS CF Polls Received Count                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                   QoS CF Polls Unused Count                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                  QoS CF Polls Unusable Count                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
[...]
   Tx Fragment Count:  A 32-bit value representing the number of
      fragmented frames transmitted.  The value of this field comes from
      the IEEE 802.11 dot11TransmittedFragmentCount MIB element (see
      [6]).

   Multicast Tx Count:  A 32-bit value representing the number of
      multicast frames transmitted.  The value of this field comes from
      the IEEE 802.11 dot11MulticastTransmittedFrameCount MIB element
      (see [6]).

   Failed Count:  A 32-bit value representing the transmit excessive
      retries.  The value of this field comes from the IEEE 802.11
      dot11FailedCount MIB element (see [6]).

   Retry Count:  A 32-bit value representing the number of transmit
      retries.  The value of this field comes from the IEEE 802.11
      dot11RetryCount MIB element (see [6]).

   Multiple Retry Count:  A 32-bit value representing the number of
      transmits that required more than one retry.  The value of this
      field comes from the IEEE 802.11 dot11MultipleRetryCount MIB
      element (see [6]).

   Frame Duplicate Count:  A 32-bit value representing the duplicate
      frames received.  The value of this field comes from the IEEE
      802.11 dot11FrameDuplicateCount MIB element (see [6]).

   RTS Success Count:  A 32-bit value representing the number of
      successfully transmitted Ready To Send (RTS).  The value of this
      field comes from the IEEE 802.11 dot11RTSSuccessCount MIB element
      (see [6]).

   RTS Failure Count:  A 32-bit value representing the failed
      transmitted RTS.  The value of this field comes from the IEEE
      802.11 dot11RTSFailureCount MIB element (see [6]).

   ACK Failure Count:  A 32-bit value representing the number of failed
      acknowledgements.  The value of this field comes from the IEEE
      802.11 dot11ACKFailureCount MIB element (see [6]).

   Rx Fragment Count:  A 32-bit value representing the number of
      fragmented frames received.  The value of this field comes from
      the IEEE 802.11 dot11ReceivedFragmentCount MIB element (see [6]).

   Multicast RX Count:  A 32-bit value representing the number of
      multicast frames received.  The value of this field comes from the
      IEEE 802.11 dot11MulticastReceivedFrameCount MIB element (see
      [6]).

   FCS Error Count:  A 32-bit value representing the number of FCS
      failures.  The value of this field comes from the IEEE 802.11
      dot11FCSErrorCount MIB element (see [6]).

   Decryption Errors:  A 32-bit value representing the number of
      Decryption errors that occurred on the WTP.  Note that this field
      is only valid in cases where the WTP provides encryption/
      decryption services.  The value of this field comes from the IEEE
      802.11 dot11WEPUndecryptableCount MIB element (see [6]).

   Discarded QoS Fragment Count:  A 32-bit value representing the number
      of discarded QoS fragments received.  The value of this field
      comes from the IEEE 802.11 dot11QoSDiscardedFragmentCount MIB
      element (see [6]).

   Associated Station Count:  A 32-bit value representing the number of
      number of associated stations.  The value of this field comes from
      the IEEE 802.11 dot11AssociatedStationCount MIB element (see [6]).

   QoS CF Polls Received Count:  A 32-bit value representing the number
      of (+)CF-Polls received.  The value of this field comes from the
      IEEE 802.11 dot11QosCFPollsReceivedCount MIB element (see [6]).

   QoS CF Polls Unused Count:  A 32-bit value representing the number of
      (+)CF-Polls that have been received, but not used.  The value of
      this field comes from the IEEE 802.11 dot11QosCFPollsUnusedCount
      MIB element (see [6]).

   QoS CF Polls Unusable Count:  A 32-bit value representing the number
      of (+)CF-Polls that have been received, but could not be used due
      to the TXOP size being smaller than the timethat is required for
      one frame exchange sequence.  The value of this field comes from
      the IEEE 802.11 dot11QosCFPollsUnusableCount MIB element (see
      [6]).

[...]
11.10.18.  IEEE 802.11 Tx Power Level

   The Tx power level message element is sent by the WTP and contains
   the different power levels supported.  The values found in this
   message element are found in the IEEE 802.11 Dot11PhyTxPowerEntry MIB
   table (see (see [6]).
[...]
   Num Levels:  The number of power level attributes.  The value of this
      field comes from the IEEE 802.11 dot11NumberSupportedPowerLevels
      MIB element (see [6]).

   Power Level:  Each power level fields contains a supported power
      level, in mW.  The value of this field comes from the
      corresponding IEEE 802.11 dot11TxPowerLevel[n] MIB element (see
      [6]).

[...]
11.10.21.  IEEE 802.11 WTP Quality of Service
[...]
   CWMin:  The Contention Window minimum value for the QoS transmit
      queue.  The value of this field comes from the IEEE 802.11
      dot11EDCATableCWMin MIB element (see [6]).

   CWMax:  The Contention Window maximum value for the QoS transmit
      queue.  The value of this field comes from the IEEE 802.11
      dot11EDCATableCWMax MIB element (see [6]).

   AIFS:  The Arbitration Inter Frame Spacing to use for the QoS
      transmit queue.  The value of this field comes from the IEEE
      802.11 dot11EDCATableAIFSN MIB element (see [6]).

[...]
11.10.23.  IEEE 802.11 WTP Radio Configuration
[...]
   DTIM Period:  This attribute specifies the number of beacon intervals
      that elapse between transmission of Beacons frames containing a
      TIM element whose DTIM Count field is 0.  This value is
      transmitted in the DTIM Period field of Beacon frames.  The value
      of this field comes from the IEEE 802.11 dot11DTIMPeriod MIB
      element (see [6]).

   Beacon Period:  This attribute specifies the number of TU that a
      station uses for scheduling Beacon transmissions.  This value is
      transmitted in Beacon and Probe Response frames.  The value of
      this field comes from the IEEE 802.11 dot11BeaconPeriod MIB
      element (see [6]).

   Country Code:  This attribute identifies the country in which the
      station is operating.  The value of this field comes from the IEEE
      802.11 dot11CountryString MIB element (see [6]).  Special
      attention is required with use of this field, as implementations
      which take action based on this field could violate regulatory
      requirements.  Some regulatory bodies do permit configuration of
      the country code under certain restrictions, such as the FCC, when
      WTPs are certified as Software Defined Radios.
[...]

Pat Calhoun
CTO, Wireless Networking Business Unit
Cisco Systems
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