San Jose, CA
·Pacific Bell - SBC
Which modem? I am not certain I trust the report of the ZTE 831 II modem I have; the modem shows, "Fastpath", but the latency is screaming, "Interleaved". Not that I care about it; I'll take the Interleaving for the stability of the connection.
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum
I've noticed the same thing with my Sonic-supplied ZTE 831II. I've seen it report "Interleave" only when the line mode is G.DMT (ADSL1). In ADSL2+, ADSL2, and READSL modes, i've only seen "Fast". I first noticed this when i was on the phone with Sonic.net support and i mentioned that, while my modem was reporting "Fast" mode, ping tests were showing unusually high latency (though not itself a problem, and not the reason for the call). The Sonic rep told me that "profile optimization" was enabled and had, in fact, set interleaving on; she didn't know why my modem was still showing "Fast".
I don't know if this misreporting of interleaving status is related to line mode (G.DMT vs. ADSL2/2+/etc.) or to the way interleaving was enabled (forced on at Sonic's end vs. automatically via profile optimization), or if it's unique to this modem.
So to answer the original poster's question, you may or may not be able to find out on your modem's status page. (Look in the FAQs and forum posts for details on getting to the admin interface of various modems; post details of your setup if you're having trouble.) If you really suspect a problem, i'd suggest calling Sonic.net support.