Sean Donelan wrote:
ATM is just a technology. Over the last decade, depending on who had the faster chipset, folks have chosen an ATM chipset, an Ethernet or even a Frame-Relay chipset for their NAPs/Exchange Points. At one point in time, the Gigaswitch was the fastest available. Then ATM switches could do 155Mbps and OC12. GigEthernet and 10 GigEthernet appeared, and folks went the other way.
Both ATM and Ethernet exchange points have route-servers. Equinix, PAIX, SBC, and Worldcom have route-servers at their exchange points in the USA. LINX and other have route-servers at exchange points outside the US. Fully filtering your peering sessions with route-servers is relatively simple.
ATM has PVCs, Ethernet has VLANs. Ethernet interface cards tend to be less inexpensive than ATM interface cards. ATM is a natural wide-area technology, Ethernet is a natural local-area technology. Frame-relay tends to be used for smaller exchange points, although it could also work in a mid-sized exchange points.
The reliability between ATM and Ethernet isn't that different over the long term. Most of the problems tend to be with the end-connections (congestion and broadcast loops), and not the fabric itself. But there have been notable outages with atm switches and ethernet switches at exchange points.
Multicast is an interesting problem in itself. None of the ATM switches handle multicast very well, and even the ethernet switches have problems.
Generally, to date, multicasting has gone on a separate switched fabric when the exchange allows it at all. Fixing this, or making it work better in general, will require Layer 3 snooping. Anyone who is interested in this should contact me off-line. Regards Marshall Eubanks T.M. Eubanks Multicast Technologies, Inc 10301 Democracy Lane, Suite 410 Fairfax, Virginia 22030 Phone : 703-293-9624 Fax : 703-293-9609 e-mail : tme@on-the-i.com tme@multicasttech.com http://www.on-the-i.com http://www.buzzwaves.com