top level aggregation (IPv6) (TLA)
The Top Level Aggregation(TLA) is a 13-bit long data field in the IPv6 address.
The TLA data field is used by the router to first identify a data packet at the highest level, i.e., Top Level Domain( TLD). At this level, the routing hierarchy can make distinctions related to organizations and transit services on the Internet.
Using the 13-bit TLA data field, routers can distinguish 8,192 (`2^13`) top-level domains (TLDs) and store them in their routing tables. The other level aggregation, Next Level Aggregation( NLA) and Site Level Aggregation( SLA), are disregarded first, which contributes to a significant reduction in address processing.