Inter-exchange media types

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


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?

Dtatacom tests were performed in the 10/100 setup. Obviously
the Fast ethernet switches had an advantage over the FDDI
switches since Fast ethernet and conventional ethernet work
with the same frame types. FDDI switches on the other hand
has to convert ethernet frames to FDDI frames and vice versa.
Todays NAPs in most cases are not 10/100 set up. It is more like
DS3/100/100 setup where routers are feeding traffic into the Gigaswitch
using FDDI and since HSSI and FDDI is using same MTU size, no
fragmentation is involved.