求翻译：Companies used to provide Internet connectivity through central proxy and content security gateways to assure consistent security policies, with state-of-the-art antivirus patterns dealing with accounting information covering all Internet activities and all with low administrative effort. While this concept has proved reliable, it is also highly cost intensive since the WAN infrastructure is based either on dedicated WAN networks (e.g. MPLS) with high bandwidth costs or cheaper VPN via public Internet. Routing all Internet trafc to headquarters and then exiting to Internet results in high data volumes and 是什么意思？

待解决 悬赏分：1 - 离问题结束还有