Our enterprise have four 6500 (the core of network), my Cisco provider want 4 modem (one for 6500) to access then by PSTN, i think this practice is a big risk, but i don't find recomendation informations about this.
You could also use a Cisco router with A/S module.
Hope that helps.
Getting Started
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: