Interim Project 

Scope and Information 


Table Of Contents

Scope 

Due Date

Status
May 2,1997  Complete  Connect all DaFIS Users  July 1, 1997  Complete  Install and Connect all Unconnected Sites  July 1, 1997  Complete  Connect RESNET  December 15,1997    Connect Unconnected Users in Connected Bldgs  November 1, 1997    Complete
Upgrade the Broadband and Serial Site Backbone 
Interim Network Overview 
The Interim Network will be in place for up to two years and will accommodate all Network 21 users. It will make use of 3COM LinkSwitching devices wherever possible to reduce cost and increase the ease of upgrading the Interim system to an ATM network. For student housing, this will involve installing desk switches and for non-housing, LinkSwitch 1000s will be used.

The existing broadband network will be upgraded to a switched ethernet backbone and will make use of the new fiber plant by 5/1/97. Buildings served by serial routers will be connected to the interim network by 5/1/97.

Unconnected buildings and all associated Network 21 NAMs will be connected to the interim network by 7/1/97. All unconnected DaFIS users will be connected to the network by 7/1/97. All unconnected NAMs, exclusive of the DaFIS users, in connected buildings will be connected to the network by 11/1/97. Student housing (RESNET) will be connected to the Interim Network by December 15, 1997.

Interim Network Design Philosophy 
  • Interim network is an 18 - 24 month solution

  • Uses switches for improved performance

  • Provides a best effort to implement VLANS by utilizing 'physical VLANs'
  • Uses the new 169.237.xxx.xxx address space to supplement the current 128.120.xxx.xxx address space
  • Minimizes future re-addressing
  • Utilizes the recently installed fiber optic cable

    • Interim Project 
    I. Sites Connected to Broadcast Backbone 

    Thirty-two sites will be augmented by replacing their connection into the backbone with a hybrid switched 10 megabit and switched 100 megabit architecture.

    These sites are identified as 'Switched' in the BB & Serial Building List.

    Design Criteria and Constraints 

    A switched backbone shall be installed that replaces the existing shared backbone such that each previously shared backbone router has full 10 megabit ethernet bandwidth available at all times.

    Sixteen existing routers will be connected to each ethernet to fast ethernet switch to ensure that at all times at least 80% of full 10 megabit ethernet bandwidth is available to those routers not connected to that switch.

    Each router connectivity switch will be connected together with the rest of the router connectivity switches by one or more 100 megabit switches so that aggregation of this traffic imposes as little round trip packet latency as possible.

    II. Serial Sites with Inadequate Capacity 
    Sixteen sites within the scope of Net 21 had serial routed connections installed to get them through until Net 21 could raise their capacity to meet the need of new applications such as DaFIS. These early interim connections range in speed from 56 kilobits with a few stations to very large installed bases connected via T1. These sites shall be connected to the existing University Network via a collapsed backbone architecture using the new fiber plant.


    These sites are identified as 'Collapsed' and Serial in the Building List

    Design Criteria and Constraints 

    A routed collapsed backbone shall be installed that replaces the existing serial router connections such that each previously 'serial' connected building has near full 10 megabit ethernet bandwidth available at all times.

    Sixteen existing router sites will be connected to a router that is located in either the NOC/MDF or, as a possible alternative, in an ADF. Each of those routers shall connect to the existing backbone at 100 megabit aggregation switches as previously installed for the upgrade to the Routers Attached to Shared Media Backbone. Each router connectivity switch will be connected together with the rest of the router connectivity switches by one or more 100 megabit switches so that aggregation of this traffic imposes as little round trip latency as possible.

    If more than one 100 megabit switch is needed for aggregation purposes, these shall be interconnected by a 100 megabit switch so as to provide as little round trip latency as possible.

    Average packet round trip latency across any two switch interfaces (including interswitch) to and from a host shall not exceed 3 milliseconds.

    The switch performing the highest level of aggregation shall also connect to the existing University network backbone at the DNS server, area server, and the existing backbone switch, all at 100 megabits, as above.

    III. Unconnected sites 
    These are very small buildings with only a handful of stations per building. Some of these small buildings are likely to want to share address space (VLAN) with other small buildings, and eventually with some of the larger existing buildings. There is an opportunity to deploy new address space in these locations to make eventual cutover much easier. This would require capturing the VLAN sizing information for those that want to join with the lager buildings so that the address space can be appropriately sized. These sites are identified as 'Collapsed' and 'Unconnected' in the Building List.

    Design Criteria and Constraints 

    A routed collapsed backbone shall be installed that connects each previously unconnected building so as to have near full 10 megabit ethernet bandwidth available at all times. Within the unconnected buildings, ethernet switches shall be installed as connection points for unconnected users. These shall be installed in such a fashion as to provide the same degree of subnetting as intended in the final Network 21 configuration. If this requires more switches that the final Network 21 configuration would require due to the efficiencies that the use of VLAN's will afford, those additional switches may be re-deployed into the final Network 21, provided those switches meet the same performance, standards and specifications as those deployed in the final Network 21.
    IV. Unconnected Users in Connected Buildings 
    DaFIS Users 

    Design Criteria/Constraints 

    New DaFIS users on existing LANs 

    Additions to existing LANs shall be designed and implemented in such a way as to preserve existing (LAN) subnetting if possible.

    DaFIS Users on New LAN's in Connected Sites

    Use the same technical approach as unconnected users in unconnected buildings including: collapsed backbone topology; Net 21 closets, fiber, and horizontal wiring; ...and new address space considerations.

    Non-DaFIS Unconnected Users in Connected Buildings 

    There may be as many as 5000 unconnected NAMs in connected buildings, excluding DaFIS users.

    New Non-DaFIS users on existing LANs 

    Additions to existing LANs shall be designed and implemented in such a way as to preserve existing subnetting on existing LANs if at all possible.

    Additions to existing LANs shall add new users to existing LAN only within same buildings as those where that LAN currently exists.

    In selecting sites for equipment to be installed, attempt to use Net21 closets, horizontal and switches where possible.

    Additions to existing LANs shall be designed and implemented in such a way as to avoid forcing cutover of existing users on existing LANs if at all possible.

    Performance and functionality shall include but not be limited to address space and existing LAN design (physical constraints, addressing constraints, ethernet standards and limitations).

    Non-DaFIS users on New LANs in Connected Sites 

    Use the same technical approach as unconnected users in unconnected buildings, including: collapsed backbone topology; Net 21 closets, fiber, and horizontal wiring; ...and new address space considerations.

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