1. An integrated end-to-end framework for network service assurance implemented using one or more computing devices, the framework comprising: a presentation layer; a service management layer; a network-infrastructure management layer; and a unified network-access layer, the unified network-access layer configured to: receive a network request in a standard abstracted format, the network request associated with at least one network element of a plurality of network elements; based on information about the at least one network element, select a vendor adaptor from a plurality of vendor adaptors; using the vendor adapter, generate a vendor-formatted network request based at least on the received network request; and send the vendor-formatted network request to the at least one network element.