Expansion - Token Ring
9-2
Single Ring
Adding New Rings
When adding new Token Rings to a chassis with an existing Token Ring network,
approach the process in the same way as you do the initial configuration of a
chassis which incorporates multiple rings. In most cases, chassis containing
existing single rings use the TRMM as a management module rather than the
TRMM-2 or TRMM-4, modules which incorporate their own Multichannel Token
Ring functions. In this case, you must add a module to the chassis which “closes
off” the first Token Ring, creates a new, separate ring, and bridges between the
two. This module is the Token Ring bridge, or TRBMIM.
After placing a TRBMIM in the chassis (to the left of the TRMIM modules of the
first ring), add station connections as you would add them to a single Token Ring
in a new chassis, by selecting the proper number and type of TRMIM modules for
the cabling type and station count you require. For a step-by-step treatment of the
Token Ring design process, refer to Chapter 6, Token Ring.
Incorporating New Technologies
A chassis which supports Token Ring as its main technology can incorporate a
bridged connection to an Ethernet network using the same module supplied for
Ethernet networks to connect to Token Rings, the ETWMIM. The ETWMIM, when
placed in the chassis, bridges the Token Ring backplane bus to either Ethernet
Channel A (in a chassis containing an IRM or EMME/EMM-E6) or an external
connection through an EPIM slot.
In order to add Ethernet connectivity to an existing Token Ring network, a
bridged connection to another chassis or a repeater module (RMIM) operating in
standalone mode must be supplied. The reason for this is based on the functions
of Ethernet and the design of Cabletron Systems modules. Ethernet networks, in
order to operate, require that repeating be supplied, either by a dedicated
Repeater/Management module or by a repeater chip located on the connectivity
module. The design of Cabletron Systems Ethernet Repeater/Management
Modules, such as the IRM3 and EMME, makes them suited for use in the first,
half-sized slot of the MMAC chassis. In an existing Token Ring network, this slot
is inhabited by the Token Ring management module.
As there is no room in the chassis to add the Ethernet management module, the
MMAC chassis cannot use the MMAC Ethernet backplane. Ethernet MIMs which
incorporate their own repeater functionality can be added to the chassis in
standalone mode, but they will not communicate with RMIMs assigned to a
different MMAC backplane channel, and cannot be managed through the
network.
Summary of Contents for MMAC-5FNB
Page 1: ...Cabletron Systems Networking Guide MMAC FNB Solutions ...
Page 2: ......
Page 4: ...ii ...
Page 10: ...viii ...
Page 188: ...Expansion Ethernet 8 12 Port Assignment and Virtual LANs ...
Page 194: ...Expansion Token Ring 9 6 Port Assignment ...