Topology: user----MA5300-----MA5200F-----public network.
It uses radius authentication.
There was 1M ADSL users, and their download speed can reach 100KB. However, when the network speed is improved, the download speed does not.
1. Check the configurations of DSLAM, and it is found that the interface speed template of the user has been changed, and DSLAM has no CAR configured.
2. Check the configurations of MA5200, and it is not configured with user-car. So BAS device is not configured with CAR.
3. Check the detailed information of MA5200 by display access-user username command; the CAR value (bandwidth) set by Radius is 1024K. Adjust the value, and the speed improvement succeeds.
Perform a test on site, and the instant speed can reach a high level, but it declines to 100K at once, indicating that some device at the network is configured with CAR.
1. When the problem occurs, check if the devices at various layers are configured with CAR, which can help locate the source of problem as soon as possible.
2. If CAR for interface is configured, the instant speed can reach a high level and then decline fast during downloading by multiple threading.