Local Tandem is any Local Only, Local/IntraLATA, Local/Access or Access Tandem Switch serving a particular local calling area.
Tandem Switch or “Tandem Office” or “Tandem” is a switching entity that has billing and recording capabilities and is used to connect and switch trunk circuits between and among End Office Switches and between and among End Office Switches and carriers’ aggregation points, points of termination, or points of presence, and to provide Switched Exchange Access Services.
Access Tandem Switch is a Switch used to connect End Office Switches to interexchange Carrier Switches. Qwest's Access Tandem Switches are also used to connect and switch traffic between and among Central Office Switches within the same LATA and may be used for the exchange of local traffic.
Tandem Office Switch or “Tandem(s)” are used to connect and switch trunk circuits between and among other Central Office Switches. A Tandem Switch does not include a PBX.