Token Ring Interface Modules

Technical Specifications

product photo

  • Transparent transport at native speeds (4 or 16 Mbps) across campus or metropolitan area networks
  • Software-selectable bandwidth allocation
  • Ring In/Ring Out interface
  • Four DB-9 lobe ports (4/16 Mbps)
  • LED status indicators
  • Easily managed through the Milgo CMS network management system, SNMP, or PremNet local console

The PremNet Token Ring interface modules provide full long-distance connectivity between token-ring networks connected to the PremNet broadband access multiplexer. With these modules, you can connect remote Token Ring networks across the PremNet backbone. This gives you a "virtual" LAN, even though the actual devices on this "LAN" can be separated by distances of hundreds of kilometers.

The PremNet broadband access system allows workgroups to be defined as virtual LANs based on the function rather than location. For example, all accounting personnel assigned to a virtual LAN can communicate as if on the same logical LAN segment, even if members are located across town in separate buildings.

Choice of PremNet Token Ring Interface Modules
PremNet Token Ring interface modules include the following:

application drawing

PremNet chassis (nodes) equipped with the 4/16 Token Ring module support multiple token-ring networks that extend far beyond the normal confines of LAN technology.

PremNet Token Ring Access
Milgo offers a 12-port external token-ring access panel (TRAP). The TRAP provides high concentration and flexibility to access the PremNet backbone, permitting remote groups of token-ring users to communicate and share resources.

The PremNet TRAP can be daisy-chained in any combination, with the RO port of one TRAP connected to the RI port of the next. Up to eight TRAPs can be connected to a single RI/RO module in this manner. The TRAP is configured through a combination of switchbank and terminal management control.

Although it is typically operated in conjunction with the RI/RO module, the TRAP can also operate in a standalone mode as a wiring concentrator, when application traffic does not need to be transported across the backbone.

Provides High-Volume Traffic
Because modules can be daisy-chained to form a ring of modules, the PremNet network can transport very high volumes of Token Ring LAN traffic on the PremNet backbone. Applications require varying amounts of bandwidth; therefore, the actual number of users depends on the number of time slots you allocate to each application.

Up to 16 PremNet nodes can be connected to form this ring topology, and up to 16 rings can be attached in a multi-ring PremNet configuration.

Truly Transparent Transport
To achieve complete transparency, PremNet builds virtual rings by connecting the geographically separate token-ring networks into a single "virtual ring". If segmentation of traffic is desired, your token-ring LAN services can easily be bridged or routed via external equipment.

application drawing

You can configure the Token Ring modules to extend an existing PremNet network. An external MAU can easily be connected to the 4/16 Mbps Token Ring module.

Token Ring Application Support
The Token Ring modules and the TRAP can be used in combination to support a wide variety of token-ring applications.

The 4/16 Token Ring module can be used to perform the following important functions:

Port Monitoring
Like all PremNet modules, Token Ring modules have a built-in microprocessor that gathers data about the module and forwards it to the PremNet network management system.

This integrated management offers detailed information and statistics about the integrity of the data passing through the card. In addition, it monitors various types of error conditions, including line code and framing errors, allowing timely diagnosis of potential token-ring problems.

Additionally, the token (or frame) counter counts all frames, giving a maximum count with no traffic on the system. During a system test, an onboard test signal can be easily sent to verify network reliability.

Choice of Network Management Interface
The PremNet 4/16 Token Ring module and the entire PremNet network can be managed from a variety of network management platforms. This allows you to use your existing Simple Network Management Protocol (SNMP)-compliant management system, the Milgo CMS management system, or the PremNet local console.

In addition to Token Ring, the PremNet family of products includes interface modules for the transparent transport of a wide variety of voice, video, and data traffic, including Ethernet, V.35, T1/E1, 4-wire voice, RS-232, RS-422, and one-way and two-way video.

application drawing

In addition to token-ring applications, PremNet transports a range of multimedia applications within a building, campus, or metropolitan area, using single-ring or multi-ring topologies.

PremNet™ Token Ring Interface Modules Technical Specifications

4/16 Mbps Token Ring

    Part Number

PN850039: 4/16 Mbps Token Ring Interface Module, 4 port, and (RI/RO)


Six DB-9 female connectors for Ring In/Ring Out and four device (lobe) ports


Two PremNet 4.7 Mbps timeslots in 4 Mbps mode or five 4.7 Mbps timeslots in 16 Mbps mode


Supports either point-to-point or multipoint applications. Multipoint applications do not require any additional bandwidth.
4/16 Mbps Token Ring RI/RO
(can be used with TRAP)

    Part Number

PN850040: 4/16 Mbps Token Ring RI/RO Interface Module


Two RJ-45 ports for Ring In and Ring Out


Ring In/Ring Out supports point-to-point for the TRAP
Compliance IEEE 802.5 Token Ring
Data Rate 4 Mbps or 16 Mbps (software-selectable)
LED Indicators LED indicators for port status: active or locked out
Configuration Maximum Up to eight modules per node; 16 nodes per ring
PremNet Branch: three modules per node; 16 nodes per ring
Environmental Operating temperature: 32 to 122 F (0 to 50 C)
Storage temperature: -40 to 158 F (-40 to 70 C)
Humidity: 95% noncondensing
Network Management Managed via standard PremNet integrated system, Milgo CMS network management systems, or an SNMP-compliant management platform
Token Ring Access
Panel (TRAP)

    Part Number

PN850042: External Token Ring Access Panel (12 ports)

    Interface Connectors

Two RJ-45 ports for Ring In and Ring Out; 12 or 24 RJ-45 device ports

Our policy of continuous development may cause the information and specifications contained herein to change without notice.

PremNet and CMS are registered trademarks of Milgo Solutions. All other logos and product names are trademarks or registered trademarks of their respective companies.

1999 Milgo Solutions. All rights reserved. Printed in U.S.A. 3C1463 3/99

Copyright 1999 - All rights reserved.

Last Modified: March 25, 1999