we have a Cisco 3745. When a user connects via ISDN PRI, everything is fine for about 210 Seconds. Then the users traffic is heavily disturbed. When I ping the user, every second ping gets lost, in the scheme: !.!.!.! and so on.
We tried firmware 12.4.13b and 12.4.16.
Under "show [users virtual interface]" I can see increasing input errors. The increase is analog to the pings. But they are already increasing from the beginning of the connection.
Users hardware interface:
There are no input errors on the users hardware interface. But when the disruption has started, for every outgoing ping there is shown an increase in outgoing AND ingoing packets (this happens of cours before the disruption, too). But wireshark and the ping process said, that every second packet is lost.
Wireshark sniffered on the connection between the 3745 and the switch ethernet interface.
What could be the reason for that behaviour? We have currently 10 users, so load should not be the problem.
Please tell me if I shall provide configfiles.