Thats what I needed a little push in tehe right direction.
So it seems totally automatic, when the T1 goes down it goes to the backup route with the 4 pots. You can set who can grab the alternate route (lines) first based on user priority and how long the lower level people have to wait before they get a dial tone in the wait time field. Here's further info from the help screen on ARS forms in manager copied here...
thanks Kevin
Alternate Route Priority
Default = 3. Range = 1 (low) to 5 (high).
If the routes specified by this form are not available and an Alternate Route has been specified, that route will be used if the users priority is equal to or higher than the value set here. User priority is set through the User | User form and by default is 5. If the users priority is lower than this value, the Alternate Route Wait Time is applied. This field is greyed out and not used if an ARS form has not been selected in the Alternate Route field.
Alternate Route Wait Time:
Default = 30 seconds
If the routes specified by this form are not available and an Alternate Route has been specified, users with insufficient priority to use the alternate route immediately must wait for the period defined by this value. During the wait the user hears camp on tone. If during that period a route becomes available it is used. This field is greyed out and not used if an ARS form has not been selected in the Alternate Route field.
Alternate Route:
Default = None.
This field is used when the route or routes specified by the short codes are not available. The routes it specifies are checked in addition to those in this ARS form and the first route to become available is used.