% APNIC found the following authoritative answer from: whois.apnic.net

% [whois.apnic.net]
% Whois data copyright terms    http://www.apnic.net/db/dbcopyright.html

% Information related to '203.150.144.0 - 203.150.158.255'

% Abuse contact for '203.150.144.0 - 203.150.158.255' is 'op-network@inet.co.th'

inetnum:        203.150.144.0 - 203.150.158.255
netname:        INET-TH
descr:
country:        TH
admin-c:        INR1-AP
tech-c:         INR1-AP
abuse-c:        AI358-AP
status:         ALLOCATED NON-PORTABLE
mnt-by:         MAINT-TH-INET
mnt-irt:        IRT-INET-TH
last-modified:  2023-08-15T09:47:06Z
source:         APNIC

irt:            IRT-INET-TH
address:        Internet Thailand Public Company Limited
address:        1768 Thai Summit Tower, 10th -12th Floor and IT Floor
address:        New Petchburi Road, Khwaeng Bang Kapi,
address:        Khet Huay Khwang, Bangkok 10310 Thailand
e-mail:         op-network@inet.co.th
abuse-mailbox:  op-network@inet.co.th
admin-c:        TY1494-AP
tech-c:         IP219-AP
auth:           # Filtered
remarks:        op-network@inet.co.th was validated on 2025-09-15
mnt-by:         MAINT-TH-INET
last-modified:  2025-11-17T23:08:36Z
source:         APNIC

role:           ABUSE INETTH
country:        ZZ
address:        Internet Thailand Public Company Limited
address:        1768 Thai Summit Tower, 10th -12th Floor and IT Floor
address:        New Petchburi Road, Khwaeng Bang Kapi,
address:        Khet Huay Khwang, Bangkok 10310 Thailand
phone:          +000000000
e-mail:         op-network@inet.co.th
admin-c:        TY1494-AP
tech-c:         IP219-AP
nic-hdl:        AI358-AP
remarks:        Generated from irt object IRT-INET-TH
remarks:        op-network@inet.co.th was validated on 2025-09-15
abuse-mailbox:  op-network@inet.co.th
mnt-by:         APNIC-ABUSE
last-modified:  2025-09-15T12:43:30Z
source:         APNIC

role:           INET NOC ROLE
address:        1768 Thai Summit Tower, New Petchburi Road
address:        Khet Huay Khwang, Bangkok
address:        Thailand 10310
country:        TH
phone:          +662 02 2577000
fax-no:         +662 02 2577275
e-mail:         noc@inet.co.th
remarks:        send spam and abuse reports to noc@inet.co.th
admin-c:        CN7-AP
tech-c:         AP224-AP
tech-c:         IP219-AP
tech-c:         NL276-AP
nic-hdl:        INR1-AP
remarks:        http://www.inet.co.th
notify:         noc@inet.co.th
mnt-by:         MAINT-TH-INET
last-modified:  2024-09-19T08:38:11Z
source:         APNIC

% Information related to '203.150.154.0/24AS4618'

route:          203.150.154.0/24
origin:         AS4618
descr:          Internet Thailand Company Ltd.
                1768 IFCT Tower, 10th-12th FL
                IT Floor New Petchburi Road
                Khwaeng Bang Kapi
                Khet Huay Khwang
mnt-by:         MAINT-TH-INET
last-modified:  2020-11-19T08:37:58Z
source:         APNIC

% This query was served by the APNIC Whois Service version 1.88.36-SNAPSHOT (WHOIS-AU5)