3Com SUPERSTACK II 2000 TR, Manual

Page: 11 / 58

2
TR-
IN
-FE C
ONCEPTS
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.