Back up is slower than usual

[Chynaliz]

We are using Symantec backup exec15 and when we run the back up, It is slower than usual, In job history, previous Job rate is 1000MB/min but now it became 500mb/min , please advise what to do to increase the performance. it was taking only 7 hours to do the process before but now it is taking 1 day already. Thanks in advance!

[kf2013]

Any change to hardware and software?

Please also check the NIC on backup exec server and agent.

I had similar experience that the NIC was changed from 1000Mb to 100Mb due to hardware problem.