Ping time

good day!
question has arisen due to increased ping.

what may be the case? at the same time with 600 clients ping less than 1 ms. Pack 1456

about every day disappears ppp - interface. when connected 800-1000 users there empty. New clients can not connect on port 1723 is not responding. old clients work fine. PPOE not work too. helps to reboot and all Restores

are your interfaces 100 Mbps? then replace them with 1G interfaces - seems like 100M is not enough

all interface 1 G intel card

what version of ROS do you use?..