Visio and excel

Hi,
I have an excel spreadsheet with more than 1000 lines. Basically the spreadheet shows all the connections between my network elements, i.e.:Site A connects to Site B with a Capacity C.
I want to make a visio drawing showing all the network connections between all the sites and show also the capacity for each connection. The site will be represented by squares and the connections will be represented by lines with a text showing the capacity.
Is there anyway that I can automate this in visio using my excel spreadheet.
I'm not very familiar with visio. I only do simple diagrams manually. If I do this task manually, it will take me a long time so I would really appreciate it if you can provide me tips on how to automate this.
Thanks