Since you have more than two network items, it is impossible to connect them all together with just one cable. You can use a "Crossover" cable in most cases to connect two network items together but when you have 3 or more network pieces of equipment that is when a HUB/Switch is required. So the next question commonly asked is do I have to buy the Furuno HUB101 or BBWX2 weather unit (that has a built in hub)? Well if you only have one MFD in these network items, then you can buy any network switch you wish, it doesn't have to be a Furuno hub. There are many out there to choose from like NetGear, D-Link, etc.... Keep in mind these off the shelf hubs are designed for 7.5 or 9 vdc so they normally don't last but about three years on a boat running 12 vdc. The Furuno hub101 is designed for a 12 or 24vdc system, and the ports are auto sensing. This means if you use a cross over where a straight cable should have been used, it will still work. The choice is yours. When you have more than one MFD, and if you want power sync to work correctly, THAT is when you NEED to buy the Furuno HUB or Weather unit to connect your equipment. I hope helps.