Computing Overall Link Throughput and Comparing with the errors occurring over the same link

Introduction

This is a continuation of the previous document of the case study on Computing accurately Overall Link Throughput.

When calculating interfaces Throughput; it is always beneficial to compare the throughput calculated directly with the registered errors on the same interface and at the same time instance. This can only be possible Using our SOSL POLL function to bind the counters and device timestamp necessary to calculate the throughput with the error counters using the same SNMP Get-Request message.    

Solution Overview

This management solution focuses on managing ONLY Serial WAN type interfaces that are NOT in a down administrative state as is set by the network administrator on the managed network devices.

The solution defines a module name, description, and initiates the polling process under which the Devices in the specified AMZ are fed into the polling SNMP engine. interfaces descriptions ifDescr MIB Objects are polled and mapped to their corresponding interfaces indexes. A variable handler is then defined to store the values of the polled ifAdminStatus, ifType, and IfOperStatus MIB Objects. Interfaces ‘up’ and of type point-to-point serial with an operational state of ‘up’ will then have their inbound octet counters, system up time, discontinuity time polled along with the number of Errors and Discards for the particular interface all   bundled in a single SNMP data unit representing the Get-Request message.

The MIB Objects values are then stored into the appropriate variable handlers for two consecutive polls which are subtracted form each other using the SOSL function CounterData which stores the results in the database.

Finally the management process script stores the second set of handler values in the first set of handler variables and polls the devices to populate the second set again. This process is repeated every 300 seconds (5 minutes).

SOSL Based Management Process Script Configuration

MODULE IfThroughput&Errors ();

DESCRIPTION "Interface Throughput Calculation With errors";

BEGIN

   MSG-MGR("Interface Throughput Calculation with Errors..");

          ALL-DEV (ZONE "RomeNet") BY DEV

          {

          SET-INDEX ifTable ( ifDescr [ ifIndex, INT ] );

          WITH-INDEX ifTable

          { 

            POLL (ifType; ifAdminStatus;ifOperStatus);

            DEFINE ifType                 DB DISPL;

            DEFINE ifAdminStatus      DB DISPL;

            DEFINE ifOperStatus        DB DISPL;

              IF   ( ifAdminStatus == "^up$")

              THEN

                   IF       ( ifTypeVar ==  "^ppp$" )

                   THEN

                             IF       ( ifOperStatus == "^up$")

                             THEN

                                      DEFINE ifInOctetsT1                   MAP INT;

                                      DEFINE ifInErrorsT1                    MAP INT;

                                      DEFINE ifInDiscardsT1    MAP INT;

                                   POLL (    ifInOctets;

                                                ifInErrors;

                                                ifInDiscards;

                                                sysUpTime;

                                                ifCounterDiscontinuityTime);

                                      DEFINE ifInOctets                      DB INT;

                                      DEFINE ifInErrors                       DB INT;

                                      DEFINE ifInDiscards                  DB INT;

                                     IfInOctetsT1      = ifInOctets;

                                     ifInErrorsT1       = ifInErrors;

                                     ifInDiscardsT1   = ifInDiscards;

                                      DEFINE sysUpTime                                DB INT;

                                      DEFINE ifCounterDiscontinuityTime          DB INT;    

                                      DEFINE Time1               MAP INT;

                                      DEFINE ifDisconTime1    MAP INT;    

                                      Time1 = sysUpTime;

                                      ifDisconTime1= ifCounterDiscontinuityTime;

                             ENDIF;

                   ENDIF;

              ENDIF;

          };

          };

 POLL-FREQ 10

   {

   WAIT (3000);

          ALL-DEV (ZONE "RomeNet") BY DEV

          {

          SET-INDEX ifTable ( ifDescr [ ifIndex, INT ] );

          WITH-INDEX ifTable

          {

            POLL (ifType; ifAdminStatus;ifOperStatus);

            DEFINE ifType                 DB DISPL;

            DEFINE ifAdminStatus      DB DISPL;

            DEFINE ifOperStatus        DB DISPL;

              IF   ( ifAdminStatus == "^up$")

              THEN

                   IF       ( ifTypeVar ==  "^ppp$" )

                   THEN

                             IF       ( ifOperStatus == "^up$")

                             THEN

                                      DEFINE ifInOctetsT2                   MAP INT;

                                      DEFINE ifInErrorsT2                    MAP INT;

                                      DEFINE ifInDiscardsT2    MAP INT;

                                   POLL (    ifInOctets;

                                                ifInErrors;

                                                ifInDiscards;

                                                sysUpTime;

                                                ifCounterDiscontinuityTime);

                                      DEFINE ifInOctets                      DB INT;

                                      DEFINE ifOutOctets                    DB INT;

                                      DEFINE ifInErrors                       DB INT;

                                      DEFINE ifInDiscards                  DB INT;

                                      ifInOctetsT2     = ifInOctets;

                                      ifInErrorsT2      = ifInErrors;

                                      ifInDiscardsT2 = ifInDiscards;

                                      DEFINE sysUpTime                                DB INT;

                                      DEFINE ifCounterDiscontinuityTime          DB INT;    

                                      DEFINE Time2               MAP INT;

                                      DEFINE ifDisconTime2    MAP INT;    

                                      Time2                         = sysUpTime;

                                      ifDisconTime2   = ifCounterDiscontinuityTime;

                             ENDIF;

                   ENDIF;

              ENDIF;

              CounterData ( ifInOctets,           ifInOctetsT1,      ifInOctetsT2);

              CounterData ( ifInErrors,            ifInErrorsT1,       ifInErrorsT2);

              CounterData ( ifInDiscards,        ifInDiscardsT1,   ifInDiscardsT2);

                   DEFINE DeltaT          MAP INT;

                   DeltaT =                 Time2 – Time1;

                   DEFINE ifDisconTime MAP INT;

                   ifDisconTime = ifDisconTime2 – ifDisconTime1;

                   IF       (ifDisconTime == 0)

                   THEN

                             DEFINE InThroughput DB INT;

                   InThroughput = (ifInOctets * 8) / DeltaT;

                   ifInOctetsT1                        = ifInOctetsT2;

                               ifInErrorsT1                         = ifInErrorsT2;

                                         ifInDiscardsT1                       = ifInDiscardsT2;

                   ENDIF;

            };

            };

   };

END

[SOSL Case Studies], [Management Concepts], [NMS Technology R&D]

[Home], [About], [Solutions Center], [NMS Market], [Products & Services],
[Management Technology], [Technical Support], [Contact us], [Site Map]