3115cn MFP Fax Modem AT Commands

How may I send AT Commands to the Fax Modem in a 3115cn MFP printer please?

I need to send it "ATS11=70&W" to overcome a very slow, lengthy, touchtone dialing tone spacing.   Fax calls are timing out.  Can I telnet or SSH into it & reach the Fax modem command line interface?

Thanks,

Sam