Yes, I have several sites where there is a WAN link router and an SRST / Voice Gateway router.
You just specify the SRST router in Callmanager.
I do find it more difficult however to have one SRST router with the PSTN links on another router. Then you need to configure dial peers between the SRST router and the PSTN router. If you can put your PSTN link on the same box as the SRST router…
