PBX, nke akpọchiri maka Exchange Branch Branch, bụ netwọk ekwentị nkeonwe nke a na-arụ n'ime otu ụlọ ọrụ. Na-ewu ewu na nnukwu ma ọ bụ obere, PBX bụ usoro ekwentị nke a na-eji n'ime ụlọ ọrụ ma ọ bụ azụmahịa site n'aka ndị ọrụ ya karịa ndị ọzọ, na-akpọ oku ụzọ na ...
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