you would have to purchase it but Netwatch from crannog software is a good package for bandwidth utilization, it gives graphs and percentages accessed via a web browser, we had a full product trial for a month so it might be worth contacting them
I have used a simple SNMP tool to check bandwidth on routers and switches, Cyberguage from Neon s/w - best thing is that the s/w is very easy to set up and use - all yoou need is SNMP read only access, the IP address and community name, and you get back b/w for each MIB 2 interface.
I have used this with Ethernet, Token Ring, FDDI, serial ISDN and frame relay links, so ATM should also be no problem
Only issue i have had is that the graphs are auto scaled based on the MIB bandwidth reported by the router, so if they are wrong you may have to adjust the settings manually.
There are MAC and windows versions, and you can download a demo copy.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...