Page 1
MMAC-Plus
™
9T122-24
Three Port Token Ring
MicroLAN
™
Switch Module
User’s Guide
Page 2
i
Notice
Notice
Cabletron Systems reserves the right to make changes in specifications and other information
contained in this document without prior notice. The reader should in all cases consult Cabletron
Systems to determine whether any such changes have been made.
The hardware, firmware, or software described in this manual is subject to change without notice.
IN NO EVENT SHALL CABLETRON SYSTEMS BE LIABLE FOR ANY INCIDENTAL, INDIRECT,
SPECIAL, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING BUT NOT LIMITED
TO LOST PROFITS) ARISING OUT OF OR RELATED TO THIS MANUAL OR THE INFORMATION
CONTAINED IN IT, EVEN IF CABLETRON SYSTEMS HAS BEEN ADVISED OF, KNOWN, OR
SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAMAGES.
© Copyright June 1995 by:
Cabletron Systems, Inc.
P.O. Box 5005
Rochester, NH 03867-0505
All Rights Reserved
Printed in the United States of America
Order Number: 9031206-01 June 95
SPECTRUM , Remote LANVIEW and LANVIEW are registered trademarks and MMAC-Plus and
MicroLAN are trademarks of Cabletron Systems, Inc.
Page 3
ii
Notice
FCC Notice
This device complies with Part 15 of the FCC rules. Operation is subject to the following two
conditions: (1) this device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
NOTE: This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial environment.
This equipment uses, generates, and can radiate radio frequency energy and if not installed in
accordance with the operator’s manual, may cause harmful interference to radio communications.
Operation of this equipment in a residential area is likely to cause interference in which case the user
will be required to correct the interference at his own expense.
WARNING: Changes or modifications made to this device which are not expressly approved by the
party responsible for compliance could void the user’s authority to operate the equipment.
VCCI Notice
This equipment is in the 1st Class Category (information equipment to be used in commercial and/or
industrial areas) and conforms to the standards set by the Voluntary Control Council for Interference
by Information Technology Equipment (VCCI) aimed at preventing radio interference in commercial
and/or industrial areas.
Consequently, when used in a residential area or in an adjacent area thereto, radio interference may be
caused to radios and TV receivers, etc.
Read the instructions for correct handling.
Page 4
Notice
DOC Notice
This digital apparatus does not exceed the Class A limits for radio noise emissions from digital
apparatus set out in the Radio Interference Regulations of the Canadian Department of
Communications.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables
aux appareils numériques de la class A prescrites dans le Règlement sur le brouillage radioélectrique
édicté par le ministère des Communications du Canada.
iii
Page 5
Chapter 1 Introduction
Features........................................................................................................................... 1-1
Related Manuals............................................................................................................ 1-4
Getting Help ..................................................................................................................1-4
Chapter 2 Installation
Installing the MicroLAN Module...............................................................................2-1
The Reset Switch ...........................................................................................................2-3
User Accessible Components ...................................................................................... 2-4
Setting the Module Card DIP Switch.........................................................................2-5
Ring Speed .....................................................................................................................2-7
Multi-Ring Out Capability........................................................................................... 2-7
Contents
Chapter 3 Operation
Bridging..........................................................................................................................3-1
Transparent Bridging............................................................................................. 3-2
Source Route Bridging ..........................................................................................3-2
Spanning Tree Algorithm...................................................................................... 3-3
Flexible Network Bus (FNB)........................................................................................ 3-4
System Management Buses .........................................................................................3-4
SMB-1 Bus............................................................................................................... 3-4
SMB-10 Bus............................................................................................................. 3-4
System Diagnostic Controller...................................................................................... 3-5
DC/DC Converter ........................................................................................................3-5
FNB Interface.................................................................................................................3-5
i960 Core......................................................................................................................... 3-5
Chapter 4 LANVIEW LEDs
Chapter 5 Specifications
Safety............................................................................................................................... 5-1
Service............................................................................................................................. 5-1
Physical........................................................................................................................... 5-2
Dimensions ............................................................................................................. 5-2
Weight...................................................................................................................... 5-2
Electrical ......................................................................................................................... 5-2
v
Page 6
Introduction
The 9T122-24 MicroLAN™ Switch Module, shown in Figure 1-1, is a three port
Token Ring bridge and router module. This module supports either one token
ring with twenty four HUB connections, or two separate Token Rings with twelve
HUB connections, and an interface to the FNB backplane.
Chapter 1
Features
Processor
The 9T122-24 is equipped with an advanced Intel i960 microprocessor. This
microprocessor provides a platform for all management functions within a
scalable RISC-based architecture.
System Management
Interfaces to the two System Management Buses (SMB-1 and SMB-10) for
intermodule management.
Connectivity
The 9T122-24 provides twenty four RJ-45 Trunk Coupling Unit (TCU) lobe
connectors. The connectors may be configured as one twenty four port ring
(default) or two twelve ports rings.
Bridging/Routing
Bridging/Routing between the front panel Token Ring connections and/or to any
other module in the chassis via FNB -1 or FNB -2 of the FNB bus. The module is
capable of Transparent Bridging or Source Route Bridging. IEEE 802.1d Spanning
Tree Protocol is supported in all bridging functions. Translational bridging
between Source Routing and Transparent Frames types is also performed.
1-1
Page 7
Introduction
Management Information Base (MIB) Support
The 9T122-24 module provides MIB support including:
• IETF MIB II (RFC 1213)
• IETF RMON MIB (RFC 1271 and 1513)
• IETF Bridge MIBs (RFC 1493 and 1525)
• IEEE 802.5 Token Ring MIB (RFC 1231)
• Cabletron Enterprise MIBs
NOTE
For a complete list of supported MIBs, refer to the release notes provided in
the module package.
Ring Security
This feature prevents unauthorized stations from attaching to the ring. Using
Local or Remote Management, the module may be configured as to which MAC
addresses are allowed to operate on the ring.
Multi-Ring Out Capability
With this feature any port of the module may be configured as a ring-out port
through management software. In this configuration a stand-alone passive
concentrator (such as an IBM 8228 MAU) may be added to the ring.
Telnet
A telnet session can be set up with the module to provide access to the Local
Management screens.
LANVIEW LEDs
The 9T122-24 use LANVIEW – the Cabletron Systems built-in visual diagnostic
and status monitoring system. With LANVIEW LEDs, you can quickly identify
the device, port, and physical layer status at a glance.
1-2
Hot Swapping
The 9T122-24 can be installed or removed from the chassis while the MMAC-Plus
is powered up without affecting the operation of the remaining modules in the
chassis.
Page 8
9T122-24
TOKEN RING
1
2
3
4
5
6
7
8
9
10
11
12
FNB
SMB
CPU
13
14
15
16
17
18
19
20
21
22
23
24
Features
2
1
16 Mb
Figure 1-1. The 9T122-24 MicroLAN Module
MMAC PLUS
1-3
Page 9
Introduction
Related Manuals
The manuals listed below should be used to supplement the procedures and
technical data contained in this manual.
MMAC-Plus Installation Guide
MMAC-Plus Operations Guide
MMAC-Plus 9C300-1 Environmental Module User’s Guide
MMAC-Plus 9C214-1 AC Power Supply User’s Guide
MMAC-Plus Local Management User’s Guide
Getting Help
If you need additional support with the MMAC-Plus, or if you have any
questions, comments or suggestions concerning this manual, feel free to contact
Cabletron Systems Technical Support:
By phone: (603) 332-9400
By CompuServe: GO CTRON from any ! prompt
By Internet mail: support@ctron.com
By mail: Cabletron Systems, Inc.
P.O. Box 5005
Rochester, NH 03867-0505
1-4
Page 10
Installation
Installing the MicroLAN Module
The MMAC-Plus MicroLAN Module may be installed into any of the 14 slots that
are available. To install, follow the steps below:
Chapter 2
1. Switch off the power supplies and remove all power from the MMAC-Plus
chassis.
2. Remove the blank panels, covering the slots that the module is being
mounted in. All other slots must be covered, if modules are not being
installed, to ensure proper airflow and cooling.
3. Carefully remove the module from the shipping box. (Save the box and
packing materials in the event the module must be reshipped.)
4. Attach one end of the ESD wrist strap packaged with the MMAC-Plus chassis
to your wrist. Plug the other end into the ESD Wrist Strap Grounding
receptacle in the lower right corner of the MMAC-Plus Chassis shown in
Figure 2-1.
5. Remove the module from the plastic bag. Observe all precautions to prevent
damage from Electrostatic Discharge (ESD).
6. Carefully examine the module, checking for damage. If any damage exists,
DO NOT install the module. Contact Cabletron Systems Technical Support
immediately.
7. The modules are installed into the chassis by sliding them into slots and
locking down both the top and bottom plastic tabs, as shown in Figure 2-1.
Take care that the module slides in straight and engages the backplane
connectors properly. When installing the module, ensure that both circuit
cards are between the card guides, as shown in Figure 2-1. Check both the
upper and lower tracks of both cards.
2-1
Page 11
Installation
7
FLNK
8
FLNK
FLNK
10
RX
FLNK
INS
TX
11
RX
FLNK
INS
TX
12
RX
Metal Back-Panel
Ensure that the circuit card is between the card guides.
Lock down the top and bottom plastic tabs
at the same time, applying even pressure.
Figure 2-1. Installing the MicroLAN Module
Jack for ESD
wrist strap
Circuit Card
Card Guides
Warning:
2-2
Page 12
The Reset Switch
SMB
CPU
The Reset switch is located on the front panel, under the top plastic tab as shown
in Figure 2-2. It serves two functions:
• Pressing the reset switch twice within three seconds causes the processor (i960)
to reset.
• Pressing and holding the switch on for three or more seconds causes the
module to shutdown. Pressing and holding again for three seconds restarts the
module.
SNMP management may be used to disable this switch to enhance module
security.
The Reset Switch
Reset Switch
Figure 2-2. The Reset Switch
2-3
Page 13
Installation
User Accessible Components
Figure 2-3 shows the various components that are accessible to the user. These
consist of an eight position dip switch (explained in the next section), replaceable
PROMs and sockets for RAM. These will be used for future upgrades.
SMB-1 PROM
i960 Processor
Flash SIMM
Socket
DIP Switch
Boot PROM
Shared Packet
Memory SIMM
Local Program Memory
SIMM Socket
2-4
Figure 2-3. User Accessible Components
Page 14
Setting the Module Card DIP Switch
Setting the Module Card DIP Switch
An eight switch DIP switch is located on the module card as shown in position 8
in Figure 2-3 and in Figure 2-4. The function of the switches are listed in Table 2-1.
1 2 3 4 5 6 7 8
Figure 2-4. Location of Module DIP Switch
2-5
Page 15
Installation
See the Cautions at the end of this table.
Table 2-1. Function of DIP Switch
Switch
8
7
6
5 Reserved For Factory Use Only
Function Description
When toggled, this switch clears user-entered
Clear
Password
Clear
NVRAM
Force BootP
Download
passwords stored in NVRAM, and restores the
1
default passwords. Once reset you can use the
defaults or enter new passwords.
The module uses NVRAM to store user
entered parameters such as IP addresses,
device name, etc. To reset these parameters to
the factory defaults, toggle this switch. Once
2
reset you can use the defaults or enter new
parameters which are stored in NVRAM when
the module is powered down, and remain
there until the switch is toggled again.
Toggling this switch after pulling the board
out of the MMAC-Plus, clears download
information from NVRAM and forces image
files to be downloaded from the station
configured to act as that modules’ BOOTP
server.
2-6
!
CAUTION
4 Reserved For Factory Use Only
3 Reserved For Factory Use Only
2 Reserved For Factory Use Only
1
1. Caution: Do not toggle Switch 8 unless you intend to reset the user
configured passwords to their factory default settings.
2. Caution: Do not toggle Switch 7 unless you intend to reset the user
parameters to the factory default settings.
Ring
Configuration
Off= One ring of 24 ports (factory default)
On = two rings of 12 ports each
Page 16
Ring Speed
9T122-24
TOKEN RING
G
R
O
U
P
1
1
2
3
4
5
6
7
8
9
FNB
SMB
CPU
The module defaults to a 16Mbps ring speed on all rings. This may be changed
though local management.
Multi-Ring Out Capability
Any port of the module may be configured as a ring-out port through
management software. In this configuration a stand-alone passive concentrator
(such as an IBM 8228) may be added to the ring as shown in Figure 2-5. This
allows for a star-wired network with the MMAC-Plus at the center. Consult the
MMAC-Plus Local Management Guide for information on configuring the ports.
Ring Speed
9T122-24
2
1
IBM 8228™
STP Cable
Figure 2-5. Using a Ring-Out Port
2-7
Page 17
Operation
The 9T122-24 MicroLAN Module provides connectivity between the front panel
Token Ring(s) and the FDDI rings on the backplane (FNB-1 or FNB-2).
MMAC-Plus modules connect to either the Internal Network Bus (INB) or the
Flexible Network Bus (FNB) bus. The 9T122-24 module connects to the FNB bus.
Shown in Figure 3-1 is a block diagram of the module. The front panel may be
configured as one Token Ring (factory default) or as two rings. In the two ring
configuration, the rings function as individual networks, each with twelve ports.
Bridging/Routing may occur between these two rings and/or to any other
MMAC-Plus module via the Flexible Network Bus.
Chapter 3
Bridging
Twelve
Front Panel
Connections
Twelve
Front Panel
Connections
DC/DC
Converter
System
Diagnostic
Controller
i960 PLUS Core
SMB-1
SMB-10
FNB-1 or
FNB-2
Figure 3-1. 9T122-24 Block Diagram
The 9T122-24 is configured for SRT bridging. It will pass SR (Source Routing)
frames between the rings and provides translation to transparent frames over the
FNB to Ethernet and FDDI modules. For information on configuring the bridging
function, see the addendum to the MMAC-Plus Local Management User’s Guide,
containing information specific to this model.
3-1
Page 18
Operation
Transparent Bridging
Transparent Bridging is accomplished by building a Source Address Table (SAT)
from source MAC/physical addresses and using the SAT to make forwarding
decisions.
The 9T122-24 prevents unnecessary network traffic from passing through the
module by implementing two separate filtering processes — IEEE 802.1d or
Cabletron’s Special Filtering Database. These processes may be used individually
or in tandem.
The first process, the IEEE 802.1D filtering process, begins with the creation of a
list of local node addresses in a table (the SAT). When the 9T122-24 first goes online, it initially forwards all packets across the bridge. After receiving a packet on
the bridge port, the 9T122-24 learns the address of the sending node from the
packet and stores that address in the SAT. In this manner, the bridge learns the
address of each node on each side of the bridge. The bridge then uses the
addresses stored in the table to compare the destination address of each
subsequent packet that travels to the bridge. If the destination address of a packet
resides on the bridge segment, the 9T122-24 does not forward across the Token
Ring link.
The second filtering process, the Cabletron Systems Special Filtering Database,
provides an additional step in the filter/forward decision. Through Remote
Management, you can define up to 10 additional filtering parameters for
incoming network traffic. These parameters include (but are not limited to) the:
• destination address
• source address
• type field (protocol)
• 64 bytes of the data field (using a data offset)
For example, using this process, you can ensure that the 9T122-24 always filters or
forwards packets with a specific protocol or address.
Source Route Bridging
Source Route Bridging operates by transmitting frames over a designated route.
Unlike Transparent Bridging, all devices in a Source Route Bridged (SRB) network
“know” the locations of other stations within the network. Using a portion of the
MAC frame header known as the RIF (Routing Information Field), the source
device determines the route for the frames it sends.
In order for source routing to work, the source station must determine the proper
route to reach the desired destination. To accomplish this:
1. The source station sends out frames called All Route Explorer (ARE) or Single
Route Explorer (SRE) frames onto the network. All Source Route Bridges
recognize these frames and forwards them to their outbound ports.
3-2
Page 19
2. The receiving bridges append their own route information to the Route
Information Field (RIF) in the MAC frame header and transmit the frame
again.
3. Eventually, the original source device receives all of the ARE replies from the
other end stations on the network.
4. From this information, the source device can determine a desired route for
each frame it transmits.
Spanning T ree Algorithm
The 9T122-24 promotes maximum network use in multiple bridge environments.
A bridge learns the bridge topology of its network from bridge protocol data that
it receives from other bridges within the network. The bridges then apply the
Spanning Tree Algorithm (STA) to select a root bridge, and then determine
primary data paths within potential data loop configurations.
Bridging
Spanning Tree Algorithm is a hierarchy (or tree) of priorities that bridges establish
between themselves. This hierarchy guarantees that primary and redundant data
paths are clearly defined at all times, so that the network is continuously available
to users.
In a multiple bridge environment, one bridge in the network establishes itself as
the root bridge. As the root, this bridge has priority over all other bridges. In a
Spanning Tree, all of the bridges must determine which bridge is the root, and
then determine their own relative priority within the network.
3-3
Page 20
Operation
Flexible Network Bus (FNB)
The FNB consists of two dual FDDI networks, the FNB-1 and FNB-2, providing
up to 400 Mbps of data bandwidth. These FDDI networks are 100% ANSI
FDDI-compliant supporting SMT (version 7.3), MAC, PHY, and PMD standards.
This allows the FNB to traverse multiple MMAC-Plus hubs, or connect to any
ANSI FDDI-compliant device, through standard A/B port connections, using the
FDDI repeater module.
System Management Buses
There are two management channels within the MMAC-Plus system: the SMB-1
and the SMB-10. These buses provide out-of-band management and inter-module
management communication.
SMB-1 Bus
SMB-10 Bus
The SMB-1 is a 1Mbs management bus located within the MMAC-Plus. This bus
is utilized by all diagnostic controllers in the system including connectivity
modules, power supply modules and the environmental module. The SMB-1
transports inter-chassis information between system components, such as power
and environmental information, as well as diagnostic messages. Periodic
loop-back test are preformed by all modules which share this bus to ensure the
validity of SMB-1. In the event a failure is detected on SMB-1, the SMB-10 may be
used as an alternate communication channel.
The SMB-10 is a 10Mbs management bus located within the MMAC-Plus which is
also used for inter-chassis communication of modules as well as serving as an
out-of-band management channel into the MMAC-Plus. The SMB-10 is
externalized from the chassis via an optional Ethernet Port Interface Module
(EPIM) located on the front of the Environmental Module. Through an EPIM
connection, full SNMP management of the MMAC-Plus is available out-of-band
from user data. Modules which share the SMB-10 bus periodically send out loopback packets to ensure the validity of SMB-10. In the event a fault is detected on
the SMB-10, the SMB-1 can be used as an alternate communication channel by the
modules.
3-4
Page 21
System Diagnostic Controller
This diagnostic controller is composed of a Z-80 microprocessor and it’s
supporting logic. The diagnostic controller is designed to control the power-up
sequencing of modules, monitor the 9T122-24 input and output power
parameters, keep watch over the main host processor, as well as monitor the
temperature and control the SMB LANVIEW diagnostic LED. Although the
diagnostic controller and the main host processor can operate independent of
each other if needed, they exchange information about each others status and
overall module condition. The information gathered by the diagnostic controller
is available to the network manager via local/remote management and the LCD
located on the environment module. The 9T122-24 have been designed so that in
the event of a diagnostic controller fault, the modules will continue to function.
DC/DC Converter
System Diagnostic Controller
The DC/DC converter converts the 48 VDC on the system power bus to the
necessary operating voltages for its host network services module. The diagnostic
controller controls the operation of the DC/DC converter.
FNB Interface
MMAC-Plus modules are designed with one of two attachment policies. One
allows a module to dual attach to either FNB-1 or FNB-2; the second allows dual
attachment to both FNB-1 and FNB-2. The 9T122-24 have one dual attachment to
the FNB backplane, connecting to either FNB-1 or FNB-2. The module can insert
into the FNB or bypass it. These flexible configuration options make the
MMAC-Plus ideal for networks designed to Bridge/Route multiple lower speed
LANs to FDDI and/or networks designed using an FDDI collapsed backbone.
i960 Core
The i960 core in the FNB module serves two major functions: it provides the
packet forwarding logic and performs all network management services. FNB
modules can be configured to run as layer 2 bridges, layer 3 routers or as
SecureFast Packet Switches. It is possible to run the bridging and routing options
concurrently, but the SFPS option cannot run with bridging and routing.
The i960 core provides the SNMP protocol stacks, as well as support for industry
standard MIBs. Additionally, Cabletron enterprise extension MIBs are supported
for each media type. Advanced management services, such as the Distributed
LAN Monitor, RMON, telnet and network address to MAC address mapping,
are also provided by the i960 core.
3-5
Page 22
LANVIEW LEDs
9T122-24
TOKEN RING
1
2
3
4
5
FNB
SMB
CPU
The front panel LANVIEW LEDs, shown in Figure 4-1, indicate the status of the
module and may be used as an aid in troubleshooting.
Chapter 4
FNB Receive
Token Ring Speed
(16mb)
System Status
FNB Transmit
Token Ring Mac Transmit
2
1
16 Mb
Token Ring Mac Receive
Link
Figure 4-1. LANVIEW LEDs
4-1
Page 23
LANVIEW LEDs
The functions of the two System Status LEDs, System Management Bus (SMB)
and the CPU, are listed in Table 4-1.
Table 4-1. System Status LEDs (SMB and CPU)
LED Color State Description
Green Functional Fully operational.
Yellow Crippled Not fully operational (i.e., one bad port).
Yellow/Green Booting Blinks yellow and green while booting.
Red Reset Normal power-up reset.
Red (Flashing) Failed Fatal error has occurred.
Off Power off Module powered off.
The function of the FNB receive LED is listed in Table 4-2.
Table 4-2. FNB Receive LEDs
LED Color State
Red No link, Port disabled
Red (Flashing) Link, Port disabled
Green Link, No activity, Port enabled
Yellow (Flashing) Activity (Flashing rate indicates rate of activity).
Off No activity
The function of the FNB transmit LED is listed in Table 4-3.
Table 4-3. FNB Transmit LEDs
LED Color State
Red
Red (Flashing) Fault or Error (Flashing rate indicates rate)
Yellow (Flashing) Port in standby state
Port disabled
4-2
Green (Flashing) Activity (Flashing rate indicates rate of activity).
Off No activity
Page 24
The function of the Token Ring Mac receive LEDs are listed in Table 4-4.
Table 4-4. Token Ring Receive LED
LED Color State
Red No link, Port disabled
Red (Flashing) Link, Port disabled
Green Link, No activity, Port enabled
Yellow (Flashing) Link, Activity (Flashing rate indicates rate of activity).
Off No link, No activity, Port enabled
The function of the Token Ring Mac transmit LEDs are listed in Table 4-5.
Table 4-5. Token Ring Transmit LED
LED Color State
Red Port Disabled
Red (Flashing) Fault, Ring is Beaconing
Green (Flashing) Activity (Flashing rate indicates rate of activity).
Yellow (Flashing) Port in standby state, Link
Off No activity, Port enabled
The functions of the Link LED are listed in Table 4-6.
Table 4-6. Port Link LEDs
LED Color State
Red No link, Port disabled
Red (Flashing) Link, Port disabled or Speed fault
Green Link, Port enabled
Off No link, Port enabled
4-3
Page 25
LANVIEW LEDs
The function of the Token Ring speed LEDs is listed in Table 4-7.
Table 4-7. Token Ring Speed
LED Color State
Yellow 16 Mbs
Off 4 Mps
4-4
Page 26
Specifications
Safety
It is the responsibility of the person who sells the system to which the module will be a
!
CAUTION
part to ensure that the total system meets allowed limits of conducted and radiated
emissions.
This equipment meets the safety requirements of:
• UL 1950
• CSA C22.2 No. 950
• EN 60950
• IEC 950
• EMI Requirements of FCC Part 15 Class A
• EN 55022 Class A
• VCCI Class I
• EMC requirements of:
Chapter 5
Service
EN 50082-1
IEC 801-2 ESD
IEC 801-3 Radiated susceptibility
IEC 801-4 EFT
MTBF (MHBK-217E) >200,000 hrs.
MTTR <0.5 hr.
5-1
Page 27
Specifications
Physical
Dimensions:
Weight:
Electrical
35.0 D x 44.0 H x 3.0 W centimeters
(13.8 D x 17.4 H x 1.2 W inches)
Unit: 1.36 kg. (3lb)
Shipping: 1.81 kg. (4lb)
CPU: i960
Shared DRAM Memory: 4Mb (expandable to 12 Mb)
Local DRAM Memory: 4Mb (expandable to 12 Mb)
Flash: 2Mb (expandable to 14 Mb)
Token Ring Interfaces: (2) Texas Instruments TMS380C26 Controllers
NVRAM: 128 Kb
5-2
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