TIA-810-B Standard for Narrowband Digital Phones May 5, 2015/在: For Purchase Telephone Sequences /通过: ZarinaThis sequence has been superseded by the TIA 920-B test sequence. More https://www.listeninc.com/wp/media/logo.png 0 0 Zarina https://www.listeninc.com/wp/media/logo.png Zarina2015-05-05 12:34:032018-10-12 14:56:49TIA-810-B Standard for Narrowband Digital Phones