It is necessary to add VOIP gateways in access layer for interlinkage between the circuit switch network and IP network so that the traditional PSTN/ISDN users can access NGN smoothly and successfully.是什么意思_It is necessary to add VOIP gateways in access layer for interlinkage between the circuit switch network and IP network so that the traditional PSTN/ISDN users can access NGN smoothly and successfully.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句