Testing LAN Performance

The performance of most LANs exceeds the capacity available in the wide area. This section asesses the performance of 10 and 100 Mbps LAN technology using Ethernet switches and hubs. The theoretical capacity of various topologies is summarised below:

Theoretical Performance

Theoretical Maximum Capacity of Various Topologies

Medium  Mode  Max Server Rate  Max Client Rate  Max Util *
 10 Mbps  Shared  10 Mbps  10 Mbps  2-10 Mbps **
 Switched  10 Mbps  10 Mbps  10 Mbps
 100 Mbps  Shared  100 Mbps  100 Mbps  2-80 Mbps **
 Switched  100 Mbps  100 Mbps  80 Mbps
 100/10 Mbps  Switched  100 Mbps  10 Mbps  10 Mbps
 155/10 Mbps  Switched  155 Mbps  10 Mbps  10 Mbps

* Maximum utilisation assuming full duplex operation.

** Maximum utilisation depends on number of nodes simultaneously attempting transmission.

Performance Measurements Results

The following delivery network topologies are examined:

  1. 10 Mbps Shared (i.e. 10 Mbps to Hub or 10Base2 or 10Base5)
  2. 10 Mbps Switched (i.e. 10BaseT to an Ethernet Switch)
  3. 100 Mbps Shared (i.e. 100 Mbps Ethernet to Hub)
  4. 100 Mbps Switched (i.e. 100 Mbps to an Ethernet Switch)
  5. 100/10 Mbps Switched (i.e. 100 Mbps Ethernet Uplink to a 10 Mbps Switch)
  6. 155/10 Mbps Switched (i.e. ATM LANE to a 10 Mbps Switch)


The performance of the Local Area Network will be measured at ERG (Ethernet and WAN measurements) and Forester Hill sites (ATM and Ethernet measurements).

The following LAN measurements were performed using the ERG JTAP Test Network. The throughput perfromance for UDP packets from both 100 Mbps and 10 Mbps interfaces were measured using the performance measurement tools developed for the JTAP project. The measured performance are reported in this section. These results are compiled from the preliminary measurements. They will be further analysed and extended in the near future.

Host Interface and Protocol Processing Performance

Host interface performance is to be analysed for the delivery PCs and SUN Ultra servers.

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