Currently i have a couple T1s going to our frame service provider, with PVCs going to about 20 remote divisions. I need to add more T1s, and to make this easier, i would like to run frf.16 with an IMUX comming in on a hssi port on my 3640. Since most of my divisions have less then 786kb, i need to run frf.12. So on to the question...can i run frf.12 on a hssi interface?