The current use for DVD drives is to watch movies. CD writable drives are available in some computer labs on campus. Both of these products are considered to be optional. You will need a network card that is 10Base-T ethernet with RJ45 jack, and a CAT5 cable with RJ45 connectors of appropriate length. These cards come in different styles to match your computer type.
Desktops usually come with internal modems built in.
If not, one can usually be added. If you have an existing computer without an internal modem, an external modem will work equally as well. A three year warranty is highly recommended. This may require the purchase of a warranty extension. On-site means the warranty provider will come to you.