Pierre-Eric,

There could be more than one reason for the server to give you that error
message.
If the scheduler works fine, so you say, check the following things:

Options on the client:
TCPIPPort:      Is the port set correctly?
                If you are backing up through a firewall, make sure the port is 
opened.
                The server attempts a connection to a client trough port 1501.
TCPIPClientadress: is the ip-adress correct?
Is the scheduler service really running, or did it hang?
Is the client scheduler account still available?
                If the scheduler is running on a certain account, check if the 
account is
locked.

Check the dsmsched.log and dsmerror.log on the client for more information.
There is a communications problem between the server and the client.

Met vriendelijke groet,
Kind regards,

___________________________________________________

Ilja G. Coolen
ABP / USZO / CIS / ES / Storage Management
Tel: +31 (0)45 579 7938
Fax: +31 (0)20 882 7286
Email : ilja.coolen AT abp DOT nl <mailto:ilja.coolen AT abp DOT nl>