SNMP information that IP Domain Maagers use to calculate interface performance

Products

• VMware Smart Assurance
• Network Observability

Issue/Introduction

SNMP information that IP Domain Managers use to calculate interface performance.

Questions answered by this article are:

• What SNMP information does Smarts use to calculate interface performance?
• How does Smarts calculate interface performance?
• What are the thresholds used by Smarts in interface performance calculations?

Environment

All Supported Smarts Releases

Resolution

The code used for interface performance calculations is compiled, so the specific formulas used in these calculations are not available for general publication.

The following sections of this article provide the threshold descriptions found in this guide and the OIDs Smarts uses for interface performance calculations.

Interface performance calculation thresholds
The following are the interface performance calculation thresholds used by Smarts: 

Broadcast Threshold
Sets upper threshold for broadcast traffic expressed as a percentage of the total bandwidth.

Collision Threshold
Sets upper threshold for broadcast traffic expressed as a percentage of the total bandwidth.

Discard Threshold
Sets the upper threshold for dropped packets expressed as a percentage of the total number of packets.

Error Threshold
Sets the upper threshold for packet errors expressed as a percentage of the total number of packets.

Error Traffic Threshold
Sets the minimum packet rate for a network adapter expressed as a percentage of total bandwidth. Value can be any number between 0.1 and 100.0.
For example, 0.2 is a valid value.

Queue Drop Threshold
Indicates the acceptable percentage of packets dropped because of full queues, expressed as a percentage of the total number of packets.

Utilization Threshold
Sets the upper threshold for link utilization expressed as a percentage of the total bandwidth.

OIDs used for interface performance calculations (with reference to RFC-1213 and RFC-1573)
The OIDs Smarts uses for interface performance calculations are the following:

• ifInOctets = ".1.3.6.1.2.1.2.2.1.10

• ifOutOctets = ".1.3.6.1.2.1.2.2.1.16

• ifInUcastPkts     = ".1.3.6.1.2.1.2.2.1.11

• ifInNUcastPkts    = ".1.3.6.1.2.1.2.2.1.12

• ifInDiscards      = ".1.3.6.1.2.1.2.2.1.13

• ifInErrors        = ".1.3.6.1.2.1.2.2.1.14

• ifInUnknownProtos = ".1.3.6.1.2.1.2.2.1.15

• ifOutOctets       = ".1.3.6.1.2.1.2.2.1.16

• ifOutUcastPkts    = ".1.3.6.1.2.1.2.2.1.17

• ifOutNUcastPkts   = ".1.3.6.1.2.1.2.2.1.18

• ifOutDiscards     = ".1.3.6.1.2.1.2.2.1.19

• ifOutErrors       = ".1.3.6.1.2.1.2.2.1.20

• ifHighSpeed          = ".1.3.6.1.2.1.31.1.1.1.15

• ifHCInOctets         = ".1.3.6.1.2.1.31.1.1.1.6

• ifHCInUcastPkts      = ".1.3.6.1.2.1.31.1.1.1.7

• ifHCInMulticastPkts  = ".1.3.6.1.2.1.31.1.1.1.8

• ifHCInBroadcastPkts  = ".1.3.6.1.2.1.31.1.1.1.9

• ifHCOutOctets        = ".1.3.6.1.2.1.31.1.1.1.10

• ifHCOutUcastPkts     = ".1.3.6.1.2.1.31.1.1.1.11

• ifHCOutMulticastPkts = ".1.3.6.1.2.1.31.1.1.1.12

• ifHCOutBroadcastPkts = ".1.3.6.1.2.1.31.1.1.1.13