I. Title

A. Name: Use of Ethernet repeaters at PennNet wallplates

B. Number: 19991022-repeater

C. Author(s): D.Kassabian, M.Wehrle, K.Victoreen, M.Levinson (ISC Networking)

D. Status:

[ ] proposed [ ] under review [ ] approved [ ] rejected [ X ] obsolete

E. Date proposed: 1999-06-30

F. Date revised: 2007-04-10

G. Date approved: 1999-10-22

H. Effective date: 1999-10-22

Policy Obsolete - April 2007

This policy is obsolete. ISC Networking & Telecommunications no longer provides repeated Ethernet service to the end user. PennNet wall plate service is 100% switched Ethernet and thus the purpose of this policy is no longer applicable to the operation of Ethernet hubs or repeaters attached to PennNet wall plates. Should one have a need to connect any active networking device to a PennNet wall plate, please reference the following network policies:

Policy on Use of Ethernet Switches at PennNet wall plates, located at http://www.net.isc.upenn.edu/policy/approved/20030922-switch.html

Policy on Routing Devices Connected to PennNet, located at http://www.net.isc.upenn.edu/policy/approved/20030310-routing.html

Links below this point have been disabled.

II. Authority and Responsibility

Information Systems and Computing's Networking organization is responsible for the operation of PennNet (Penn's data networks) and therefore has the authority and responsibility to specify requirements for any devices connecting to PennNet. This authority extends to the device type in the case of networking electronics such as a router, repeater, or switch. It also extends to certain configuration parameters of a device which could adversely impact other parts of the network.

III. Executive Summary

This policy specifies the conditions under which an Ethernet repeater may be connected to a PennNet wallplate, and refers to a list of eligible locations. It also provides "best practice" recommendations to guide the network user in deploying repeaters appropriately.

IV. Purpose

The purpose of this policy is to identify the locations and circumstances in which an Ethernet repeater may be connected to a PennNet wallplate. While multiport Ethernet repeaters can be convenient in providing access to multiple networked devices in locations where only one PennNet wallplate port is available, use of repeaters in certain situations can cause significant problems (see V. Risk of Non-compliance). This policy allows the network user to take advantage of the convenience of multi-port repeaters in cases where doing so will not adversely affect the provision of network service to others.


V. Risk of Non-compliance

Use of repeaters in certain situations is a violation of IEEE standards cited below. This can cause significant problems (poor performance, communication failure, etc.) for other users of PennNet. Additionally, it can make troubleshooting the network more difficult and time consuming.

VI. Scope

This policy applies to any device acting as an Ethernet repeater, including wireless devices acting as an Ethernet repeater. An Ethernet repeater (also called a repeating hub or concentrator) is a device that repeats, retimes and/or reshapes a signal received on one port, sending it to all other ports. This policy does not apply to hubs which perform a bridging or switching function.

Restrictions on the use of Ethernet repeaters apply to all standard PennNet wallplates. Network wallplates that are provided and supported by organizations other than the University's central networking organization are not covered directly by this policy. Network users are advised to check with their local LSP if uncertain.

VII. Statement of policy

The use of Ethernet repeater devices to connect computers, printers, and other networked items to a PennNet wallplate is permitted only in buildings that have been certified by ISC Networking as "repeater ready". The official list of "repeater ready" buildings can be found at


In buildings that are "repeater ready," the following limitations apply to the use of Ethernet repeaters:

  1. ISC Networking provides support up to the wallplate only, and therefore will not be responsible for the operation of the repeater device unless installed by ISC Networking for specific temporary purposes, such as traffic profiling or troubleshooting.

  2. Repeaters may not be "cascaded" or "daisy-chained" (ie, no connections from one repeater to another repeater).

  3. The repeater and all associated station wiring must remain in the same room with the physical wallplate.

  4. The use of repeaters or switches may not be specified or substituted into a building (re)wiring design, such as in an attempt to reduce the number of wire pulls to a location or office.

VIII. Recommendations and Best Practices

The following related practices are strongly recommended by ISC Networking, towards a more efficient network.

    1. All available data ports on wallplates should be activated for PennNet service and put to use before the network user resorts to the use of a repeater on that wallplate. Use of wallplate ports rather than repeater ports will provide the user with more bandwidth, lower contention, and more advanced features that will become increasingly important as new applications are deployed.

    2. Repeaters connected to PennNet wallpates should connect no more than four (4) devices to PennNet. Building networks are designed to maximize efficiency and performance based on certain assumptions about network node and traffic density.

    3. Repeaters should be wall-mounted near the wallplate whenever possible, and wiring should be kept out of walking paths to reduce risks of accident.

    4. Where new wiring centers and pathways are being provided as part of a construction project, an opportunity to install new wiring should always be taken. (Note: ISC Networking is also responsible for managing all new wiring installations.)

IX. Compliance

A. Verification: ISC Networking does not plan to actively police the network in an effort to discover non-compliant repeater devices, but will act on those discovered during the normal course of events in operating and/or troubleshooting the network.

B. Notification: Notification shall be made to the LSP for the area. Whenever possible and practical, the user of the repeater-connected node(s) will also be notified.

C. Remedy: Remedy will be the immediate removal of out-of-compliance repeaters. Interim solutions to retain connectivity may in many cases be available through ISC Networking.

D. Financial Implications: The network user will be responsible for the costs of any new port activation or new wiring, and any costs for interim solutions where applied.

E. Responsibility: Responsibility for remedy (and associated costs) lies with the network user. In the vast majority of cases, the area LSP will have involvement in the implementation of the remedy.

F. Time Frame: Non-compliant connections must be remedied immediately to reduce risk of networking failures for other network users. Interim solutions, which may involve having the network user rent ISC-owned equipment, should be made available by ISC Networking (where possible and with the cooperation of the network user) within 2 business days to allow the network user to continue to receive service. Final solutions should be implemented within 30 days.

G. Enforcement: Please see the Policy on Computer Disconnection from PennNet at http://www.upenn.edu/computing/policy/disconnect.html

H. Appeals: Please see the Appeals section of the Policy on Computer Disconnection from PennNet at http://www.upenn.edu/computing/policy/disconnect.html

X. References