Lub thawv xaim hluav taws xob ua raws li qhov chaw thauj mus los hauv lub zog hluav taws xob, nws txoj haujlwm tseem ceeb yog kev faib hluav taws xob hluav taws xob. Cov kev teeb tsa muaj xws li 1-hauv-4-tawm lossis 1-hauv-6-tawm tsim:
Cov kab nkag: Txuas mus rau lub cable tseem ceeb, feem ntau yog siv ib zaug - cov khoom siv hluav taws xob.
Outgoing Line: Ua haujlwm ntau- cov qauv tsim hluav taws xob tsim hluav taws xob, muaj peev xwm muab lub zog ib txhij rau ntau qhov chaw.
Cov xwm txheej: Cov chaw nyob hauv cheeb tsam siv hluav taws xob feem ntau siv 1-hauv-4-tawm kev teeb tsa, thaum cov chaw lag luam yuav xav tau 1-hauv-8-tawm teeb tsa.
