Re: speed up query

[Rick James]

SHOW TABLE STATUS -- I need to see how big these tables are.
Please use aliases on all field when you have JOINs (srnup).
Is there some reason for the ids to be NULLable?
How many rows in dsl_data are there for a typical day & port_id?
Minor bug: BETWEEN is causing you to have midnight in two days.
"int(3)" should probably be TINYINT UNSIGNED (4 bytes -> 1 byte)

  PRIMARY KEY (`id`),
  KEY `idx_site_ip_id` (`id`),

The second is redundant an probably should be removed.

Changing
KEY `idx_dsl_data_port_id` (`port_id`)
to the compound key:
INDEX (`port_id`, time)
would help some.