I have one service of the Voice and IP. I use vanguard 340E at data services. My telephony is separate via Parks Modem ( used with DM ). My problem is, when i plug my cisco 2500 in parks modem, my telephony down, and my internet link not encaminhate e-mails of the > 1MB. In annex, post my configurations, configuration of the ISP and debug ppp. What's wrong? Best reggards.