LAN - Next Steps
Double aggregate bandwidth ~ every 12-18 months
- more segmentation (hubs => switched ports, 1 host/collision domain)
Dedicated 100Mbps Ethernet to power user desktops
Gbps trunks between switches & core routers
Replace FDDI rings with high speed switched core
Higher speed routing & more integrated with switching
1997: 5.1 host / collision domain
Now: 3.6 hosts / collision domain
Hubs are on their way out.
We did a pilot ATM (OC3) vs Fast Ethernet evaluation with BaBar,
and decided the extra complexity & cost (e.g. LANE which is limited to MAC
layer and MPOA is further out and even more complex) is not worth it for
the LAN and will probably go with Gbps Ethernet, we do not have the
real-time LAN requirements (e.g. video, voip, multimedia) that drive ATM.
Even the traditional ATM strongholds og QoS & real-time are now being
addresses by IP and Ethernet.
Intel working with Layer to provide Gbps over Copper (72% of
installed nets are copper), demo early 1999, but will it work on existing Cat5 for
100meter, if not then probably move to fiber?. 100Mbps to a few desktops at
SLAC. Do not see beyond 100Mbps to desktop in general use for about 5 years,
so UTP Cat 5 OK for a while.