Издательство: | Книга по требованию |
Дата выхода: | июль 2011 |
ISBN: | 978-6-1331-2069-3 |
Объём: | 72 страниц |
Масса: | 129 г |
Размеры(В x Ш x Т), см: | 23 x 16 x 1 |
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Via Net Loss (VNL) is a network architecture of telephone systems using circuit switching technologies deployed in the 1950s with Direct Distance Dialing and used until the late 1980s. The purpose of the VNL plan and a five-level long distance switching hierarchy was to minimize the number of trunk circuits used during a call and maximize the voice quality achieved on each circuit. Excessive noise or loss meant that subscribers may have difficulty hearing each other. This was particularly important in the 1960s when dial-up data applications were developed using analog modems.
Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.