North American Network Operators Group|
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical
Re: Where are ATM NAPs going?
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 : [email protected] [email protected] http://www.on-the-i.com http://www.buzzwaves.com