The ATM Switches
There are many ATM switch manufacturers, but only a handful are serious competitors. For example, Marconi offers the ASX-4000 for the backbone edge provider switches, and the ASX-1000 for customer access ATM switches.
We will use Marconi as a sample backbone hardware configuration.
Comparing the older Nortel Vector edge switches with Marconi ASX-4000. The new edge switches are more robust, and offer HEC mapping, which has a lower overhead than the PLCP mapping of the Vector switches. The Vector switches offer DS1, DS3, and OC3 UNI speeds. The Marconi ASX-4000 adds OC12 to that array of available UNI speeds. Each Marconi switch has dual IMT's to two other remote ATM The provider sites.