All things related to multicast

[Russ Hobby <>]

A few months back at a CENIC TAC meeting I polled the member campuses about 
the state of multicast and found that several campus had backslid and had 
less multicast penetration then a couple of years ago.  Most of those that 
backslid indicated it was because that they installed new equipment 
(usually routers) and had not turned on multicast, either because they saw 
no demand to do so, or the new equipment was different to configure 
multicast and they had not figured it out yet (again demand would have made 
a difference).  A couple of other cases  multicast was turned off because 
people did start using it, but that broke unicast (or all networking).

The latter was the case here at UC Davis.  We have an ATM Backbone running 
LANE.  Muitcast goes thorough the Broadcast Unknown Servers, a limited 
resource.  So when multicast traffic got to the point where it was swamping 
the servers, netops just turned it all off and will only turn on multicast 
on special request to specific locations.  Fortunately the ATM network is 
scheduled to be replaced in a couple of months.

Russ