What is Q-series protocols?
Also called Series Q protocols, a set of protocols developed by the International Telecommunication Union (ITU) that includes the following:
Q.920/921: Specifies the User-Network Interface (UNI) data-link layer for Integrated Services Digital Network (ISDN), including the ISDN D channel’s Link Access Procedure D (LAP-D) data-link protocol.
Q.922A: Specifies the ITU encapsulation method for frame relay networks.
Q.931: Specifies mechanisms for establishing, maintaining, and tearing down ISDN connections. This includes working with connections in the LAP-D data-link protocol, which runs on the ISDN D channel.
Q.93B: The Asynchronous Transfer Mode (ATM) signaling protocol, which specifies mechanisms for establishing, maintaining, and tearing down broadband ISDN (B-ISDN) connections.