mms-out.movistar.com.ar has no NS records.
NS records for this zone are defined at movistar.com.ar.
NS records for this zone are defined at movistar.com.ar.
Question and response
Question
dig mms-out.movistar.com.ar. NS
Answer
The response has no answer records.
Authority
movistar.com.ar. 600 SOA nsvel1a.tgt.net.ar. admindnsmovistar.telefonicamoviles.com.ar. 2016041677 1800 900 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0