proc ModifyStreamFrameSizeHlt { trafficItemName framesize } {
    # trafficItemName = The Traffic Item name in exact spelling.
    # framesize = The framesize value to modify.

    # Note: The stream_id format = ::ixNet::OBJ-/traffic/trafficItem:1

    set trafficItem [GetTrafficItemByName $trafficItemName]
    if {$trafficItem == "" || $trafficItem == "0"} {
	puts "\nError ModifyStreamTransmitModeHlt: No such Traffic Item name: $trafficItemName"
	return 1
    }

    puts "\nModifyFrameSizeHlt: $trafficItem : $framesize"
    set trafficItemStatus [::ixia::traffic_config \
			      -mode modify \
			      -stream_id $trafficItem \
			      -frame_size $framesize \
			      ]

    if {[keylget trafficItemStatus status] != $::SUCCESS} {
	puts "\nError ModifyFrameSizeHlt: $trafficItemStatus\n"
	return 1
    }
    return 0
}