Specifications

RADring
Installation & Operation Manual Functional Description
3/11/98 12:33 Radring Functional Description - Token Ring 2-3
2.3 Radring Functional Description - Token Ring
General
The RADring is a compact modular access center enabling connection of
stations to IEEE 802.5 Token Ring networks and IEEE 802.3 Ethernet
networks.
RADring provides a highly granular and flexible approach to building a
Token Ring and Ethernet networks. It also ensures high network reliability
and fault tolerance.
Radring
Enclosure
The RADring enclosure provides housing for a single common logic card
(CML or CML/NM), a maximum of 20 modules, up to two power supplies,
and up to two cooling fans (one for each power supply in High Power
module). The passive back-plane ensures continued integrity of the ring
even when modules are not inserted. The Ethernet backplane provides
connections of all the EP modules into one shared segment. In addition, the
back-plane provides a communications bus between the common logic
card and all modules. The operation of each module is independent of the
operation of the common logic card. A Token Ring in-band management
card (CML/IB) can be installed in up to four rings per hub, to provide in-
band management. The CML/IB-E card is installed in the hub to provide
Ethernet in-band management and connectivity to RADview.
The optional redundant power supply ensures the continued operation of
the entire hub if one of the power supplies fails. The power supplies are
located at the rear of the chassis, each unit with its own AC mains
connection (it is recommended that the power supplies be connected to
separate mains sources). During operation the power supplies provide load
sharing, which ensures a “hot standby” function in the event of a power
supply failure. Hot insertion and removal of the power supplies can also be
performed without affecting the network. In the case of a general power
failure (blackout, etc.), the hub is bypassed without interfering with any other
units on the ring.
System
Configuration
Operation
The functional operation of the RADring system depends on the
configuration of the hub. The RADring hub operates in a similar principle to
regular TAU (Trunk Access Units). Each ring is defined as a group of lobe
modules (TL-2, TL-4), enclosed by Ring In and Ring Out modules. The
main path signal enters the ring from the left-hand side via a Ring In card.
The signal continues to travel through the ring until it encounters a Ring
Out card, or terminating card. Because the RADring hub is a split bus, it
can support multiple rings within a single hub. The following examples
explain the signal path in different configurations: