DECA system is used in conjunction with the SWM LNB, SWM8 or SWM16 to give receivers internet access through the coax coming from the SWM Switch * The DECA network is a shared 200Mb/s, or the same speed as full duplex 100Mb/s Ethernet * Multi-Room Viewing Feature requires a SWM system, and compatible DIRECTV receiver. Every receiver requires a DECA or Band Stop filter except H24, H25, HR24, and HR34. * HR20-100 receiver requires a Band Stop Filter for this system to work * Using a DECA prevents the diplexing of an off-air antenna, because they both use the same frequency