proc addTrafficItemPacketStack {configElementObj protocolStackNameToAdd stackNumber action} {
    # Example:
    #    addTrafficItemPacketStack $configElementObj udp 3 append
    # 
    # Parameters
    #    configElementObj: The configElementObj object handle
    #    protocolStackNameToAdd: mpls, ipv4, etc.
    #    stackNumber: The stack number to insert before or append after.
    #    action: append or insert.
    #            append goes after $stackNumber, insert goes before $stackNumber
    
    set index [lsearch -regexp [ixNet getList [ixNet getRoot]/traffic protocolTemplate] $protocolStackNameToAdd]
    set stack [lindex [ixNet getList [ixNet getRoot]/traffic protocolTemplate] $index]
    
    puts "\tAdding stack: $stack"
    set addToStackLevel [lindex [ixNet getList $configElementObj stack] $stackNumber]
    ixNet exec append $addToStackLevel $stack
    ixNet commit
}