IEEE 802.9, also known as Integrated Services LAN (ISLAN), pertains to the integration of voice and data over the same network. The 802.9 standard was designed to support both time-critical services like voice and video as well as data traffic over a single network. This was accomplished by using Time-Division Multiplexing (TDM) methods.

Here are a few highlights:

  1. Integration of Services: The main goal was to provide an integrated service where both data and voice could coexist on the same local area network (LAN).
  2. Data Rate: The standard originally aimed to provide data rates up to 20 Mbps.
  3. Application: It was primarily targeted for office environments, where there would be a need for voice (like telephone) and data (like computer networks) services.

However, the rapid advancements in other networking technologies and protocols somewhat overshadowed the popularity and application of IEEE 802.9, leading to it not being as widely adopted as some of the other IEEE 802 standards like 802.3 (Ethernet) or 802.11 (Wi-Fi).