AT$H11

B0       ITU-T V.22 when line speed is 1200 bits/s                                      

B1       Bell 212A when line speed is 1200 bits/s                                       

B2       V.23 originate/answer: T75/R1200 when DTE speed is 1200 bits/s                 

B3       V.23 originate/answer: T1200/R75 when DTE speed is 1200 bits/s                 

B15      V.21 when line speed is 300 bits/s                                             

B16      Bell 103 when line speed is 300 bits/s                                         

B30      V.22 bis when line speed is 2400 bits/s                                        

B41      V.32 when line speed is 4800 bits/s                                            

B52      V.32 bis when line speed is 7200 bits/s                                        

B60      V.32 when line speed is 9600 bits/s                                            

B64      V.FC when line speed is 9600 bits/s                                            

B70      V.32bis when preferred line speed is 12000 bits/s                              

B71      V.FC when preferred line speed is 12000 bits/s                                 

B75      V.32bis when preferred line speed is 14400 bits/s                              

B76      V.FC when preferred line speed is 14400 bits/s                                 

B81      V.FC when preferred line speed is 16800-28800 bits/s                           

B82      Reserved for V.terbo when preferred line speed is 16800-19200 bits/s