HP 2820 - Manual (Page 26)

Interface ports
The device has two interface ports: a 10/100Base-T (RJ-45) network port and a Hi-Speed
USB 2.0 port. The HP Color LaserJet 2830/2840 all-in-one models also have fax ports.
1 network port
2 Hi-Speed USB 2.0 port
3 fax ports (HP Color LaserJet 2830/2840 all-in-one models only)
10 Chapter 1 Device basics ENWW