Thanks for providing inputs. Yes agreed, invoking external freeze and external thaw operations to perform suspend and resume system. Thaw operation working as expected , but externalFreeze operation failing, I believe these issue with authentication issue. Is there way to address authentication issue to fix through Cache object script using $ZF(-1) function  or any other option .

OS level authentication we enabled through admin console and got succeeded in the Windows Command prompt execution but same is failing through cache object script code.

Thanks for providing useful information. Above mentioned approach works in windows command prompt. But through Cache Object script,

##Class(Backup.General).ExternalFreeze()  method response is incorrect. In case of ##Class(Backup.General).ExternalThaw() response works as expected because this method could  not expects credentials. Only issue with externalFreeze() method. Any help on this issue?