Control Logix Bandwidth

I am working on Upgrading our Ethernet infrustucture and IT want me to tell them what my Bandwidth Requirments are. Is there a way to know that with knowing the amount of connections to a controller?

I have 1756-ENBT and 1756-EN2T

can they mesure the actual use...?

Be carefull as AB is multicast

Thats what I asked but I might have to go
do that myself I guess

If you are using wired Ethernet with 100 Mb/s full duplex switches, then even a fully loaded 1756-ENT2T will use maybe 2 to 5 percent of the available bandwidth of the Ethernet switch system.

The only systems I have ever seen with actual network bandwidth problems were those running wireless links in between segments.

I would tell the IT department "get me 100 Mb/s full duplex, switches with IGMP Snooping, and a router that does IGMP Querying that I can manage", and don't worry about the rest.

The problem is we are still using Analog connections with maybe 128k speed maybe 56k speed some places. So when i am at a station on a controller then go on internet i kick ooff our SCADA network, or i remote into a HMI i kick off SCADA. We have managed switches that are 100 Mb/s full duplex
but our connection speed and bandwidth is bad.

I want all digital with Full T1 connections min of 512

OK, so you're in one of those circumstances where the WAN is part of your automation system.

The #1 thing you can to do help your network is learn basic Wireshark usage. I've seen a great many WAN systems that carry totally un-necessary traffic that uses up valuable bandwidth.

You just can't predict what an HMI or programming connection will need without measuring what you use now. That's where Wireshark comes in tremendously handy.

I am a big fan of the m0n0wall and PFSense firewalls, based on FreeBSD. These have "traffic shaping" features that could let you reserve bandwidth for the SCADA system when you're sitting in a remote site. These firewalls are easy enough to install and use that even a ordinary Windows user can set them up.

With Ken's approach you should be able to determine exactly what is wrong.

However, I approach this problem a bit differently in each of the control networks I design. I ALWAYS put a router in place to create separate networks for the control devices, the HMI's, the information network LAN, and any WAN connection. Then I route only those ports or protocols between networks that I know have to cross networks. This absolutely ensures the control network will NEVER be affected by any other traffic.

A good router will tell you where all your traffic is occurring, and, if you segment as I suggested above, which ports or protocols are attempting to cross network segments. Then you simply forward the appropriate traffic exactly as you need. I have been using the Zyxel (Zywall 2+ for small networks, USG 100/200 for larger networks) for a few years and have never been disappointed. They have a great GUI so you never have to learn some cryptic language like Cisco's IOS. And the Zywalls have never failed me - either with features or hardware failures. I use them in all my industrial designs (even though they are not an industrial-rated device). There are many 'good' routers that will do what you need as long as you spend the time to figure them out.

Gotta use an IGMP snooping switch! If possible, I'd even consider using a seperate wireless network for the control systems. Then, when some guy is downloading movies of Lindsy topless it won't screw up the controls

Be careful about adding a managed switch (with igmp snooping) and expecting it to fix your problems in this case. All igmp does is separate your multicast domains and that does not sound like it will address your described situation. A good router will allow you to separate traffic in unique domains and also permit you to set qos for each domain when your limited wan speed comes into play.