A cellulose acylate film comprising cellulose acylate which has a degree of crystallinity represented by the following expression of 0. A transparent horizontally loading folded sheet protector, with a \xbd\u2033 ring retaining extension on the right edge of the back panel, was designed to mount onto the rings of this binder. A DSL multiplexer has a DSL current rate detector for supplying DSL rate information indicative of a currently set DSL rate, and transmits the ATM cells from the IPATM converter or the IP packets from the packet scheduling apparatus to user terminals through DSL processing using telephone lines.