[PLUG] SSH session hangs over WiMAX

[Jeff_W]

(3rd attempt at posting this; guess mailman is picky)

I recently opted to try Clear.com's WiMAX Home service [1] as a replacement
for DSL.  The Home service consists of a Motorola CPEi150 [2] bridge(?)
device that connects the Clear's WiMAX transmitter and does NAT and DHCP
and some basic firewalling.  It's a dynamically assigned IP unless one
shells out an extra $10/month for a static IP.

Anyways, while basic web surfing seems to work fine, ssh sessions are
either disconnecting or just hanging frequently, usually within 5-10
minutes.  Doesn't seem to matter if I'm actively typing or just running
something like top(1).  I tried adding ServerAliveInterval <sec> with
various time intervals (180, 240, 300) to my ssh_config file without much
improvement.  It's pretty annoying and I'm almost to the point of boxing
it up.  Anyone have any insight as to what might be the problem?  An online
chat with Clear's support service wasn't particularly enlightening; the
tech thought perhaps packet splitting might be the cause.  My NIC is
currently set at MTU=1500 - pretty standard I think.

I'm about 5 days into the 7 day evaluation period, after which I'm locked
into Clear's two year WiMAX contract, so any timely feedback would be
greatly appreciated.  Off-list replies are encouraged as I'm subscribed
to the list's digest.

Thanks,
Jeff

[1] http://www.clear.com/shop/home_services.php
[2] http://www.motorola.com/business/US-EN/CPEi+150_US-EN.do?vgnextoid=617323805ae46110VgnVCM1000008406b00aRCRD