I don't have an answer offhand. It is dependent on a lot of things. Are you talking about an ESS user, ITIL user, or an integration?
An ESS user is going to have minimal interaction with the website and only use it when they need to read/open a ticket. These are going to be the majority of the users in SN but probably not constitute the majority of the platform usage or bandwidth.
An ITIL or admin user is going to spend a lot more time within the instance. They will probably constitute the majority of the platform usage just based on how they need to interact with the platform to do their jobs.
For the ITIl or ESS users, you could probably just run a packet capture over an allotted period of time and get a pretty good estimate of the bandwidth used.
When you get to integrations, that is where it can get more tricky to count.
* Do you have scheduled imports from a third party application coming in? Is it a batch job or is it real-time web services?
* Do you utilize the CTI integration, where all your calls get information passed into Service-now tickets
* Do you have lots of scheduled reports being mailed out to users?
* Are you utilizing SN Discovery? The probes coming from the MID server don't always generate a lot of traffic but there will be a lot of them, and all the data needs to be returned via SOAP to the Service-now instance.
You can still do the packet capture, but the inputs can be a lot more variable in nature. Your infrastructure team would probably have a better idea on how to properly measure it within your environment.
