The core needs two local area network (LAN) ports to support the external and internal networks. The way this is generally done is use the motherboard's onboard LAN and to install a network interface card (NIC) for the second port. The transmission speed on the external network will be limited by your provider, but the internal network is only limited by your hardware. Gigabit hardware is not required, but might be nice for the internal LAN. Most LinuxMCE networks are a combination of wired and wireless. The major data-intensive components in your system (core, media directors, NAS) should be wired with cat5e or cat6. Orbiters are generally wireless because they move very little data and are designed to be portable remote controls. It is up to the user where to store data. For instance, a ripped movie collection could be stored on the core, on a media director, or on a NAS. The LinuxMCE software will find the collection and make it available to the entire system.
Network Attached Storage http://wiki.linuxmce.org/index.php/Category:Network_Attached_Storage
Network Interface Cards (NICs) and Chipsets http://wiki.linuxmce.org/index.php/Category:Network_Adapters
Routers and Switches http://wiki.linuxmce.org/index.php/Category:Routers
Network Tutorials add Category: Network Tutorials