Are those other servers all connected to the SAN? The reason I am asking is that you haven't mentioned this, and if you don't then your jobs are going across your LAN. 2TB of data will take a long time as a result.
Something to look into is Backup Exec's SAN SSO option. Instead of backups running across your LAN, they will run directly across your SAN and make use of that speed (2 or 4GB vs. 100 or 1000MB), and backups should complete much quicker. That's the upside...the downside if you need to load that option on a server designated as a SAN SSO server, and then you need to load full versions of Backup Exec on each SAN-attached server, and run a wizard to configure them to use that server.
I used this option on our Head Office site before it got virtualised, and cut backup times by 60%.
If this is too pricey, I'd look into using a FULL/INCREMENTAL backup strategy. This will ensure that your daily jobs go through successfully, and quite quickly too, leaving your weekly job to run over a weekend.
I take it your CAS is initiating the jobs? I run a CAS in our environment, and basically use it for monitoring only. THe site servers do their own management of, and initiating of jobs. A major reason for this is the WAN speeds into Africa and Asia.