This chapter provides an introduction to Token Ring-in-Fast Ethernet concepts for users who are unfamiliar with this technology. The following sec- tions cover:
■What is Token Ring-in-Fast Ethernet (TR-in-FE)?
■TR-in-FE Compared to Traditional Methods
■3Com Token Ring-in-Fast Ethernet System
■How TR-in-FE Works
■Tunneling
■Virtual LANs (VLANS)
What is Token Ring-in-Fast Ethernet (TR-in-FE)?
Token Ring-in-Fast Ethernet is a 3Com developed technology that encapsulates Token Ring frames in Fast Ethernet frames. Bridging the gap between Token Ring and Ethernet, this technology offers a more cost-effective integration than traditional bridg- ing and routing, and allows Token Ring users to expand their bandwidth while preserving their TR infrastructure.
Using Token Ring-in-Fast Ethernet technology, Fast Ethernet can be used as a cost-effective and scalable aggregation point for multiple Token Ring switch con- nections. In addition, because both Token Ring and Ethernet technologies can coexist in the same Fast Ethernet infrastructure, both can share to less costly Fast Ethernet connections.
Through a process known as tunneling (see the “Tunneling” section below), TR-in-FE uses Fast Ether- net to transport natively formatted Token Ring frames. This means that both source route and trans- parent TR frames addressing information is main- tained through Fast Ethernet (FE) so that it may be interpreted and utilized by either a destination Token Ring (TR) switch or FE server.
