IEEE 802.6 is a standard that relates to Metropolitan Area Networks (MANs). Specifically, it defines a Distributed Queue Dual Bus (DQDB) system, which was one of the early standards for MANs. Here are some key points about IEEE 802.6 – DQDB:
- Purpose: IEEE 802.6 was designed to cover wider areas than Local Area Networks (LANs), bridging the gap between LANs and Wide Area Networks (WANs). It was aimed to serve metropolitan areas, which can span up to 40 kilometers (about 25 miles).
- DQDB (Distributed Queue Dual Bus): The architecture is based on two unidirectional buses that transmit data between nodes. Each node on the network connects to both buses but transmits on one and receives on the other.
- Access Mechanism: The DQDB protocol uses a distributed queue system. Nodes wanting to send data would place a request in the queue. Once they have permission to send, they can transmit their data packets.
- Bandwidth: The DQDB system was designed to support high data rates suitable for both voice and data communication.
- Support for Broadband ISDN: The 802.6 standard was considered as one of the means to implement Broadband Integrated Services Digital Network (B-ISDN) services.
- Decline: With the rise and domination of IP-based networks and other standards, the popularity and implementation of DQDB-based MANs have waned.
In the broad spectrum of networking standards, IEEE 802.6 had a specific purpose for metropolitan areas, serving as a bridge between local and wide-area networks. However, newer technologies and evolving network architectures have since overshadowed its utility.