1. Maintenance Items
  2. 0121
  3. Request
Requested revision
Standard:IEEE 802.1AB-2009Clause:8.5.8, 11.2, 11.5.2
Clause title:System Capabilities TLV, Structure of the LLDP MIB, LLDP MIB module - version 2
Rationale for revision
1. In Section 8.5.8 Figure 8-10, System Capabilities TLV is shown to have a "Chassis ID subtype" as shown below, which is wrong. Chassis-ID subtype should be part of Chassis-ID TLV.

|----------------------------------------------------------------------------------------------------------|
| TLVTYPE | TLV information string length | Chassis-ID subtype | System Capabilities | Enabled Capabilites |
|----------------------------------------------------------------------------------------------------------|

2. In Section 11.2, Table 11-2 ? LLDP MIB structure and object cross reference, below MIB objects are maintained globally instead of per LLDP Agent

lldpV2MessageTxInterval 
lldpV2MessageTxHoldMultiplier 
lldpV2ReinitDelay 
lldpV2NotificationInterval 
lldpV2TxCreditMax 
lldpV2MessageFastTx 
lldpV2TxFastInit

As per the mapping shown in the table for above MIB objects, they map to variables maintained per LLDP Agent.

3. In Section 11.5.2 for lldpV2MessageTxHoldMultiplier OBJECT-TYPE, TTL value is computed as per the logic shown below

TTL = min(65535, (lldpV2MessageTxInterval * lldpV2MessageTxHoldMultiplier))
Proposed text
1. Correct System Capabilities TLV format should be as shown below

|-------------------------------------------------------------------------------------|
| TLVTYPE | TLV information string length | System Capabilities | Enabled Capabilites |
|-------------------------------------------------------------------------------------|

2. As per the section 9.2.5 msgTxInterval, msgTxHold, reinitDelay, txCreditMax, msgFastTx and txFastInit are per LLDP Agent variables. 
Per Agent MIB objects should be maintained under lldpV2PortConfigTable.

<BEFORE>
lldpV2PortConfigTable
  lldpV2PortConfigIfIndex                       (Table index)
  lldpV2PortConfigDestAddressIndex              (Table index)
  lldpV2PortConfigAdminStatus                   adminStatus, 9.2.5.1
  lldpV2PortConfigNotificationEnable            ?
  lldpV2PortConfigTLVsTxEnable                  9.1.2.1

<AFTER>
lldpV2PortConfigTable
  lldpV2PortConfigIfIndex                       (Table index)
  lldpV2PortConfigDestAddressIndex              (Table index)
  lldpV2PortConfigAdminStatus                   adminStatus, 9.2.5.1
  lldpV2MessageTxInterval                       msgTxInterval, 9.2.5.7
  lldpV2MessageTxHoldMultiplier                 msgTxHold, 9.2.5.6
  lldpV2ReinitDelay                             reinitDelay, 9.2.5.10
  lldpV2NotificationInterval                    msgTxInterval, 9.2.5.7
  lldpV2TxCreditMax                             txCreditMax, 9.2.5.17
  lldpV2MessageFastTx                           msgFastTx, 9.2.5.5
  lldpV2TxFastInit                              txFastInit, 9.2.5.19
  lldpV2PortConfigNotificationEnable            ?
  lldpV2PortConfigTLVsTxEnable                  9.1.2.1

3. In Section 11.5.2 for lldpV2MessageTxHoldMultiplier OBJECT-TYPE, TTL value should be computed as shown below according to section 9.2.5.22

TTL = min(65535, (lldpV2MessageTxInterval * lldpV2MessageTxHoldMultiplier) + 1)
Impact on existing networks
1. Wrong system capability TLV is sent in LLDPDU. 2. Current 802.1AB-2009 MIB has no option to obtain variables per-agent.
Originator
Name:Ajith. AdapaEmail:adapa.ajith@gmail.com
Affiliation:IPInfusion
Submitted:2013-07-09