KbA0002: Bandwidth (Internet ) consumed by a CopperCube

The product applies to CopperCube.

Description

I am concerned about traffic volumes on my Internet connection. How much outgoing bandwidth does a CopperCube consume?

Solution

Obviously, the amount of bandwidth used is a function of the number of trend logs, & objects the CopperCube is collecting and the number of controller databases it discovers needing to be backed up. All of which is a coarse reflection of site size.

For starters, let’s examine some statistics from the outgoing transmission queue of a reasonably large CopperCube. This is a snapshot of the queue that has been running for months – so the stats will have settled down to their long-term steady-state values.

The important questions are: 1) How many TLs go out each day? How big is each one? 2) How many BACnet Objects go out each day? How big is each one?

Trend log collection

Exhibit A: a CopperCube TL Transmit Queue:

Statistics on the Trendlog collection

These statistics show:

  • each TL update (the amount of data collected each time a controller TL is visited) averages 1.7K
  • by default, TLs are collected every 4 hrs (i.e. 6 updates per day). So every TL generates 1.7K x 6 = 10.2K / day
  • Let’s assume there is a 25% overhead (for packet headers, response packets, etc). Call it 12.75K per TL per Day.
  • Let’s assume your CopperCube is collecting the maximum 5000 TLs at the default rate = 5000 x 12.75K = 63750K / 1024 = 62.3 MB/day

BACnet Object collection

Exhibit B: Objects Transmit Queue:

The BACnet Object collection transmission queue

BACnet Objects are highly variable in size and quantity, but given that these statistics show:

  • BACnet Objects average out to 0.8K each
  • all objects of interest (<50% of all available objects) are collected once daily.
  • Let’s assume there is a 25% overhead (for packet headers, response packets, etc). Call it 1K per object per day.
  • Let’s assume your CopperCube is collecting 50000 Objects (a 10:1 Object-to-TL ratio) daily. So 50000 x 1K = 50000K / 1024 = 49 MB/day

Database Backups

By default, controller databases are backed up once a week. A typical DAC database is 200K. Since this is not a daily item, let’s exclude this traffic from the discussion.

By adding the TL data volume to the BACnet Object data volume, we can determine that:

  • a maximum loaded 1CopperCube will generate 62.3MB + 49MB = 111.3 MB/day of outgoing traffic.
  • this traffic is spread across the 24 hr day. Yielding 111.3 MB / 84600sec = 1.4 K/sec.
  • In Internet bandwidth terms: an extremely small amount of traffic.
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