Telecommunications and exchange between information technology systems - Requirements for local and metropolitan area networks - Part 1AX: Link aggregation

1.1 Scope
Link Aggregation provides protocols, procedures, and managed objects that allow the following:

• One or more parallel instances of point-to-point links to be aggregated together to form a LinkAggregation Group (LAG) so that a Link Aggregation Client can treat the LAG as if it were a single link.
• Conversation-Sensitive Collection and Distribution (CSCD) that specifies a means to identify the distribution algorithm in use to assign frames to individual links in a LAG and to convey that information to the System at the other end of the LAG.
• Distributed Resilient Network Interface (DRNI) that enables a LAG to terminate at a pair of cooperating Systems in order to provide system-level as well as link-level resiliency.

1.2 Purpose
Link Aggregation allows the establishment of point-to-point links that have a higher aggregate bandwidth than the individual links that form the aggregation and the use of multiple systems at each end of the aggregation. This allows improved utilization of available links in Bridged local area network (LAN) environments, along with improved resilience in the face of failure of individual links or systems. In applications connecting separately administered networks, the networks are isolated from each other’s fault recovery events.

1.3 State diagram conventions

This standard uses the state diagram conventions in Annex E of IEEE Std 802.1Q™-2018.1

When implementation of a state diagram is required for conformance, all states and transitions shown with solid lines shall be implemented. States and transitions shown with dashed lines may be implemented. If a conflict exists between a state diagram and either the corresponding global transition tables or the textual description associated with the state machine, the state diagram takes precedence.

Information on references can be found in Clause 2.