I need to connect 800 series router to 2600 router. 800 series is main router and connected with ISP. I have four ethernet port on 800 series router. 2600 series router is for internal IP phone (7960) connection testing. 2600 series has only one ethernet port. What card do i need to use on the 2600 series router to connect with 800 router aslo with Poe Switch+IP phone.