As a important part of VoIP network, IP phone gateways are usually produced on PC platform, router platform or switch platform and may have high average channel cost, less flexibility and inadequate QoS.

• 目前，作为VoIP网络重要组成部分的IP电话网关，一般是在微机、路由器或者交换机平台上实现，造成其均线成本偏高、系统灵活性不够、服务质量不稳定。