What are you referring to by " if they'll do appropriate things with gigE, ISDN BRI ?"
An RJ45 jack will be pinned out ok for POTS, Ethernet of all speeds, and ISDN. Aside from it's promise of surge protection, all it really has to do is maintain an electrical connection between your two patch cords.
Now re. the cable inside from the [in jack] to the [out jack], I would hope that the connecting cable inside between the in and the out is twisted correctly to maintain shielding up to at least CAT5 standards, maybe even CAT6 (either might be pushing it.) But honestly, I'm not sure. I wouldn't be surprised to see straight pairs.
Even if wasn't, the very tiny distance from the in jack to the out jack probably wouldn't result in enough distance to degrade the signal. Although, maybe being in close proximity to so many other power cords introduces a problem? Damn it! Stop making me paranoid. LOL!
Perhaps our local electrical engineer can fill us in.
