Yes, I think you can do it on a 1710 as well.
I assume that your primary is 30.30.30.30, backup is 40.40.40.40
crypto isakmp policy 20
encr 3des
authentication pre-share
group 2
crypto isakmp key sharedkey address 30.30.30.30
crypto isakmp key sharedkey address 40.40.40.40
crypto isakmp keepalive 10 20
! to keepalive when primiry site down and build up tunnel with backup site
!
crypto ipsec transform-set dsltest esp-3des esp-md5-hmac
!
crypto map test 10 ipsec-isakmp
set peer 30.30.30.30
set peer 40.40.40.40
set transform-set dsltest
match address 101
Best Regards,