Nokia 7750 Service Router and Nokia 7450 Ethernet Service Switch - Any service any port media dependent adapters. The Nokia 7750 Service Router (SR) and 7450 Ethernet Service Switch (ESS) Any Service Any Port (ASAP) Media Dependent Adapters (MDAs) provide valuable options for delivering highly scalable multiservice, multi-encapsulation connectivity for IP/MPLS-based routing and services.