Inter-exchange media types

Sun Apr 28 07:49:52 UTC 1996

On Thu, 25 Apr 1996 12:34:25 -0400  Curtis Villamizar wrote:

>For many products, there is a big difference between how many
>interfaces physically fit in the card cage and how many actually work
>under a fairly heavy load.  Have you tested a 12 port switched 100
>Mb/s ethernet under load?  The DEC gigaswitch has been tested under
>load and has held up so far under load.  The Cisco 5000 may bridge
>better than it routes since there is no route change to deal with, but
>I'd be a bit worried about deploying without stress testing.
>
>The problem for the major exchanges may soon be what to do when the
>gigaswitch runs out of bandwidth.
>
>Curtis
>

The Feb 1996 issue of Data Communications ran a benchmark on these switches
along with a few others.  I will just summerize the Digital and Cisco info
that they state:

Cisco Catalyst 5000 - Full duplex Ethernet, half duplex FDDI, full duplex fast 
Ethernet; Max: 96 Ethernet, 4 FDDI, 50 Fast Ethernet; Price: $22K for chassis, 24 
Ethernet ports, 2 FDDI

Digital Gigaswitch - Ethernet, Full Duplex FDDI; Max: 12 Ethernet, 8 FDDI; Price: 
$21K for chassis, 24 Ethernet ports, 2 FDDI

Benchmarks:

a) % of frames delivered without loss (100% load on 40 ports):
   Burst size (in 64 byte frames)
   24: Cisco 99%   DEC 76%
   62: Cisco 100%  DEC 75%
   124: Cisco 100% DEC 65%
   372: Cisco 100% DEC 51%
   744 Cisco 100%  DEC 49%

b) % of frames delivered without loss (64 byte frames, 24 frame bursts on 40 ports):
   70%: Cisco: 100%  DEC: 81%
   80%  Cisco   99%  DEC  79%
   90%  Cisco   99%  DEC  85%
   100% Cisco   99%  DEC  75%
   150% Cisco   99%  DEC  22%

c) Per port thruput: 64 byte frame per second (24 frame bursts on 40 ports)
   Cisco: 4891 
   DEC:   4391

d) Latency (microseconds) - 64 byte unidirectional traffic across 100Mb backbone
   Cisco:  79
   DEC    179

Bottom line: The Gigaswitch performed the  almost the worst (Fibronics took that 
honor) and the Cisco performed the best.

Perhaps it is time to revisit the Gigaswitch technology?

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Hank Nussbacher                  Manager, Internet Technology Programs
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