长途电路 meaning in Chinese

toll circuit
trunk circuit

The mgcph . 248 end mode in soft switching and the pure sip mode will be more suitable for the application of ip metropolitan area network of the lan access ; while the big media gateway of the soft switching mode will more suitable to replace the existing local or circuit switch ( packet switch )
软交换中mgcph . 248终端方式和纯sip方式更适应在lan接入的宽带ip城域网上开放；软交换中大媒体网关的方式更适应替代现有的本地或长途电路交换机。