Upto 2MB connections, the default queueing is WFQ, which is weighted fair queueing, which gives higher weights to interactive traffic such as telnet. compared to bandwidth hogging apps such as a file transfer, ftp session.

Give a show queue serial 0 and you should get the queueing strategy thats currently enabled on the interface. It should be written weighted fair for WFQ.

If you additionally want, high priority for telnet and low for everything else, you can use priority queueing.

Key in the following commands.

priority-list 1 protocol ip high tcp telnet

int s0

priority-group 1

The above commands create a priority list of protocols, with telnet traffic in the high queue, while the rest by default goes to normal queue.

and priority-group 1 command attaches this priority list to the physical interface.

If you want to make it more granular by specifying ip addresses of end points, you can use the "list " parameter for the priority-list, and create an access list matching the telnet traffic specific to either host.

HTH