Can I bring my Freephoneline adapter to South East Asia??

Hello everyone,
I'm planning on bringing my Freephoneline adapter with me to Southeast Asia in countries like Cambodia/Vietnam. Will it work? Am I able to use it as I would at home and receive calls?
Anyone have knowledge, background or experience with this, please let me know. Much appreciated.
I'm planning on bringing my Freephoneline adapter with me to Southeast Asia in countries like Cambodia/Vietnam. Will it work? Am I able to use it as I would at home and receive calls?
Anyone have knowledge, background or experience with this, please let me know. Much appreciated.