Comparing POS and ATM interfaces
R. Hay · Computer · 2000
Carrier-class Internet service providers (ISPs) must choose an appropriate interface for long-distance data transmissions. The two technologies they most often choose are packet-over-Sonet (POS) and asynchronous transfer mode (ATM). Vendor devices implement POS and ATM to transport data over Sonet (Synchronous Optical NETwork)-a standard for sending data over fiber-optic cables-and SDH (Synchronous Digital Hierarchy), which is Sonet's international equivalent.