Ullumbana ceremony according to vietnamese buddhist tradition

In Pali literature, Pethavatthu in Khuddhaka Nikaya recorded story about venerable Sariputta and his mother in previous life. A story entitles Sariputta thera Matu Petivatthu Vannanna which notes the existence of Ghost realm with many suffer, pain and distress. One time Buddha was staying at Bamboo garden who retold this story. Sariputta was dwelling in the forest not far from Rajagaha. At that time a Peti as female ghost arised who wanted to meet venerable Sariputta. But Deva heaven rejected her to reach his abode. She begged them and spoke that she was his mother in the fifth past life. Final Sariputta saw her through out of loving meditation state. She was suffering with hungry, thirsty, no cloth, no home and expected his saving. Sariputta and Mahamoggallana (Sanskrit: Mahamaudgalyayana) went to the residence of king Bimbisara asked king for supporting. King Bimbisara built huts, water, food, fruit and all life necessary things to Sariputta. Afterthat he offered them to monks in four direction and transfer great credit to his mother. She received it and reborn in heaven as Devi. This story roots in India which inspires for establishment a nice tradition as known as Ullambana festival which appreciates about the filial piety conduct. It is the foundation duty of human being for parents. Ullambana ceremony is observed in many Buddhist countries as China, Japan, Korea, Viet Nam. In this article explains, analyses, discusses in limited area for Ullambana ceremony according to Vietnamese Buddhist tradition which will have some characteristics different with another Buddhist countries