How are you using the modem? Are you using it for remote out of band management of your devices, then no you are not using IP. You are using Asyncronous ASCII with start/parity/stop bits. If you are using your modem for link to link router connectivity or remote access via an Access server or remote authentication then your modem will use either PPP or SLIP for its layer 2 protocol upon that you can use IP as your transport all this using the modem as your medium access... Hope I helped....
