WJEC Digital Technology Practice Test

The key concept is symmetry in the data stream: a broadband service where upload and download speeds are the same. Commercial organizations often need to send large amounts of data as well as receive it—things like backing up data to the cloud, hosting services, or video conferencing—so having equal upstream and downstream bandwidth is important. Symmetric Digital Subscriber Line (SDSL) provides that balance, delivering the same data rate in both directions over the same copper line. That makes it well suited to business needs where reliable bidirectional performance matters, without the compromise of a slower upload path. Other options don’t fit as well. ADSL is designed to maximize download speed over upload, which isn’t ideal for businesses frequently sending data upstream. Cable and Satellite typically offer higher download speeds but are not truly symmetrical and are often shared among many users or subject to higher latency, making them less reliable for consistent two-way data transfers required by commercial users.